Starry Nights

Eldritch eyes in the sky watch over Halloween revelers

2008-10-28T22:54:00.001-07:00

Eldritch eyes in the sky watch over Halloween revelers
by Dave Adalian

Tomorrow night, when ghosts and goblins, witches and all sort of evil thing take to the streets for Hallowe’en, an eerie trio of eldritch eyes from the early evening southwestern sky will watch them as they go.

Just after the sun sets at six o’clock, a new moon a scant few hours old will become visible a handful of degrees atop the horizon. With only the barest slice of its leading limb lit by dying sunlight the moon might look not entirely unlike the giant bloodshot eye of some cosmic creature leering down as costumed children dart among the neighborhood houses, collecting their treats and playing their tricks.

This ominous orb may be so thin it hides among wisps of lingering autumn mist, so seek for it instead by finding Venus, shining just above the moon like a baleful, unblinking witness, then wait until the sky grows darker and the moon more distinct.

Sometime also in that first hour after dark the tiny red light of Antares will appear, a bloody jewel beneath the moon. So, too, will the brighter stars of a setting Sagittarius come out, cold and shimmering beside the moon, and there above them will be Jupiter glaring out into the night.

Those three sky-bound watchers will not contain their vigil to a single eve, and the moon will float between the other two like an unquiet spirit, moving past Venus then up beyond Jupiter as the first few long November nights unfold.

These three probing autumn eyes and their glittering companions are not the only specters lingering in the heavens on Hallowe’en night. High overhead, three bright stars form a mystic triangle: white Vega in Lyra the farthest west of the group, Altair in Aquila at the south-most vertices and Deneb in Cygnus cutting the eastern angle.

In the north the Big Dipper lies low against the horizon with its bowl open, perhaps to gather candy or to be filled with water from Aquarius on the other side of the sky for cosmic apple bobbing. As always, the Dipper’s two end stars point the way to Polaris, and there beside the North Star is the W shape of Queen Cassiopeia, a ghoulish woman who would have fed her own daughter to the sea serpent Cetus.

Then in the east above the mountains the wraithlike Seven Sisters of the Pleiades begin their nightlong journey toward the west, and midnight finds them at the zenith when Halloween turns to All Saints’ Day.

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This column originally appeared in the Visalia (Calif.) Times-Delta and the Tulare (Calif.) Advance-Register.

Starry signs point toward fall

2008-09-23T10:06:00.000-07:00

Starry signs point toward fall
by Dave Adalian

‘You know Orion always comes up sideways.
Throwing a leg up over our fence of mountains
And rising on his hands he looks in on me. ...’
-- Robert Frost, The Star Splitter

It’s that time again, when we pack away summer in our memory and all too soon turn our thoughts to woolen hats, warm coats and icy fog.

Some of us declare the season at an end when Labor Day rolls around and we spend three lazy days enjoying the last few hours of summer heat with barbecues, long stretches of green grass and cool dips. Others of a more serious and scientific mind say the season passes on the equinox, as the Sun, our giver of life and warmth, turns south again to shine on more exotic lands.

I suppose they’re right, but for me the change of season is measured by the stars.

First sure sign summer’s at an end comes just after dark when the Summer Triangle of Vega, Deneb and Altair sits directly overhead insisting that the season isn’t quite over yet, not yet! But we know better, and each next long night finds them farther west than the one before.

If that weren’t evidence enough, when we turn to the east we find four bright stars in an enormous square -- the Great Square of Pegasus -- looming, and there beside it to the northeast the glowing ghost of the Andromeda Galaxy, a haunting specter of a Hallowe’en soon to be.

In the hour before midnight, when the Square takes the place of the Triangle at the top of the sky, the raging bull of Taurus begins its autumn charge over the eastern mountains: Aldebaran a glowing red eye in the V-shaped face of the Hyades and the seven starry sisters of the Pleiades riding on its back.

Were there any doubt left in us by the hour after midnight, the giant figure of Orion climbing sideways into the sky would chase it from our minds. The ancestor of us all, this ancient man of the mountain has come again to rule over the long, cold nights of a winter not yet quite begun.

In that coldest hour just before dawn, Orion the Hunter, followed by the faithful Dog Star Sirius, takes his stand in the south where he looks over the harvest and waits for the frozen chase to begin. Autumn has arrived.

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This column originally appeared in the Visalia Times-Delta and Tulare Advance-Register in August 2008.

Triple conjunction challenges eagle-eyed planet hunters

2008-08-27T09:33:00.000-07:00

Triple conjunction challenges eagle-eyed planet hunters
by Dave Adalian

The next two weeks present a challenge for planet hunters in possession of either keen eyes or a pair of binoculars. Those who take up the difficult task will also need an unobstructed view of the western horizon and patience.

About half an hour after sunset tonight, Venus should be obvious to the naked eye directly west and around 10 degrees or about two hand-widths above the horizon in sunset’s afterglow.

The most eagle-eyed might also see dimmer Mercury shining in the gloaming less than a hand-width to the left of Venus. Those of us without such keen vision will have to resort to binoculars. Just about any will do, though a magnification of at least seven times is recommended.

But, even those with the sharpest of eyesight likely won’t find dim Mars just two hand-widths above and to the left of the Goddess of Love. For that, binoculars are a must, but the extra effort will be worthwhile as this trio draws into an ever tighter triangle during the first half of September.

While the God of War is still about 10 degrees separate from the Goddess of Love, by next Wednesday the distance will be half that. Four days later on Sept. 7, Venus and Mars will be only 2.5 degrees apart. The gap will be only 1.75 degrees the next night, and a mere 1.5 the night after that.

On Sunday, Sept. 10, the two planets will appear less than a single degree apart, and on Sept. 11, when the two are at their closest, only three-tenths degree separates them.

During the close call on Sept. 11, when Love and War appear almost on top of one another, remember they’re really millions of miles apart. Though they look close enough to collide, Venus is 138 million miles away from Earth, while Mars is 227 million miles distant.

Mercury, meanwhile, is a relatively close 88 million miles away from Earth.

While this triple conjunction unfolds, the trio will be setting earlier night to night, so by the end even the keenest of eyes will need binoculars to follow the show. Just don’t point them at the sky until after sunset to avoid eye damage.

For a beautiful bonus look for the new moon near the trio on Sept. 1, when it will hover just above the horizon but below the planets, and again on Sept. 2, this time off to their left.

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This column originally appeared in the Visalia Times-Delta and Tulare Advance-Register in August 2008.

Earth’s Seven Sisters are out this Week

2008-08-19T17:52:00.000-07:00

Earth’s Seven Sisters are out this Week
by Dave Adalian

All seven of Sol’s other planets are out this week, and with a little luck and patience earthbound planet hunters will be able to collect them all.

Tonight (Aug. 21, 2008) is the night to be lucky -- and careful -- to find the first target. Saturn follows the sun over the western horizon about 30 minutes after sunset, making it a difficult target for the naked eye.

Because it’s bright, Saturn should turn up in the reddened western sky glow. For safety sake, start searching for the ringed planet only after Sol’s disk has completely disappeared. This is especially true when using binoculars: Viewing the sun through optics will cause vision loss.

If Saturn won’t cooperate tonight, Friday and Saturday are also possibilities, but chances of seeing the sixth planet grow slimmer each night.

After the search for Saturn, finding Venus and Mercury will be a breeze. (Well, easier anyway, but because they’re so low the search might still require the aid of binoculars.)

The innermost planets are in close conjunction for the next few days, and can be seen together above and to the left of where the sun met the horizon at sunset. The pair may also help locate elusive Saturn: it will be between the pairing of the first and second planets and the sun.

Follow that imaginary line connecting Sol, Saturn, Mercury and Venus -- the ecliptic -- further up and to the left to find ruddy Mars. The Red Planet is now so far away it’s little more than a reddish pinpoint, but like all the planets it doesn’t twinkle. Again, binoculars will help.

King Jupiter is impossible to miss, shining bright in the south on the shoulder of Sagittarius the Archer after sundown. The only reason for binoculars here is to search for the planet’s larger moons.

Binoculars will be a must to find Neptune, the eighth planet out. Look for Neptune’s tiny blue-green disk about halfway up the sky due south at 30 minutes after midnight tonight. After Pluto’s demotion, Neptune is now the farthest planet out.

Closer in but farther out along the ecliptic at present is the seventh and final planet, Uranus. It will be due south about 2 a.m., and can be seen with the naked eye. Because Uranus is at the edge of the eye’s range, binoculars will help you locate it. A finder chart will make finding both Uranus and Neptune much easier.

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This column was originally intended for publication in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register in August 2008. For some reason that didn't happen. I don't know why. So, I wrote them another one, which is the next post after this.

War, Change and the Little King

2008-07-01T16:20:00.000-07:00

Planets and Stars Gather:
War, Change and the Little King
by Dave Adalian

Look to the west tonight between sunset and 10 o’clock and you’ll find a pair of planets and a bright star artfully grouped just above the reddened horizon.

All year long, the ringed planet glided slowly through Leo the Lion while angry red Mars sat nearby in Cancer the Crab. As summer reaches its height, the War God is on the move, slipping into the lion’s den to join Saturn, Roman god of change and growth.

As the trio stands now you’ll find ruddy Mars between the brightest star in Leo, brilliant white Regulus, on Mars’ right and yellowish Saturn to its left. Although low to the horizon, the Bringer of Change still outshines almost everything else in the sky.

Of the three, Mars is smallest and closest, only 4,000 miles wide at its widest, compared to Saturn’s nearly 75,000-mile girth (or 150,000 miles if you count the rings, which are the largest structure in the Solar System after Sol).

But, Mars, Saturn and even Sol are dwarfed by Regulus, which carries a bulk three and a half times the sun’s. It’s about that many times as wide in the middle, too. Regulus -- the star’s name means “little king” -- also spins faster than the sun. Sol turns once each month; Regulus turns once every 16 hours, almost fast enough to fling the star apart, but not quite. It is fast enough to make Regulus oblate, meaning it’s squashed flat like a cosmic M&M candy.

Tonight, Mars will be closer to Regulus than Saturn, but the two planets are headed for a very close encounter on July 9-10, with Mars seeming to move steadily in Saturn’s direction during the next seven days. All during the week, the trio will make for spectacular viewing, and the show gets even better on the nights of July 5 and 6 when the conjoined planets and Regulus are met by a young crescent moon, which will be below the trio the first night and beside it the second.

This event effectively marks the end of the Saturn viewing season, and Mars and Saturn won’t be this close again until 2022, but planet hunters take heart: While Saturn and Mars are leaving the sky, Jupiter, Saturn’s son and king of the planets, is coming into its best, appearing as the brightest thing in the sky. Find it by looking southwest after sundown.

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This column originally appeared in the Visalia (Calif.) Times-Delta and the Tulare (Calif.) Advance-Register in July of 2008.

Stupid Questions

2008-06-01T16:20:00.000-07:00

Stupid questions: the dark of night reveals more than empty space
by Dave Adalian

Why is the night dark?

It sounds like one of those questions you have to be stupid to ask, but the answer can lead to a deeper understanding of how our universe works.

To be fair there is more than one answer because there’s more than one reason the sky at night is dark. The obvious reason is that at night we’re on the far side of the planet from Sol in the shadow of the Earth, so it’s dark. Simple.

But, why isn’t the night sky lit with all the shine from the uncountable number of stars aglow in the heavens? It’s the answer to this second question that’s revealing to the inquisitive mind.

If we lived in a finite universe with an even distribution of stars endless daylight is exactly what we’d see. Because the energy would have nowhere to escape, the stars would warm their surroundings until the entire universe glowed evenly with their heat.

But, that isn’t what we see.

It wasn’t until 1829 that it occurred to astronomer Charles Olbers to ask why the night is dark, and he was promptly ignored. No one had an answer for him then.

One hundred years later, another astronomer, Edwin Hubble, noticed the farther away from us an object is the more its light is distorted when it arrives here. The distortion is caused by speed, and the farther away something is the faster it appears to be traveling. The universe, Hubble had discovered, is expanding at an ever greater rate.

So what?

So imagine a party with 200 people in your living room and more on the way. There would be activity everywhere you looked, someone doing something, laughing, drinking, dancing, talking. You’d be overwhelmed like dim starlight on a bright day.

Imagine that same party in an airplane hanger and the place would seem practically deserted, dark and empty.

Now, what if your living room got bigger every time a new guest arrived? No matter how large and raucous the party became your living room would never seem crowded and the guests would never overfill it.

Strange as it seems, that’s how the universe appears to operate. The older the universe gets the larger it grows, and if we had stopped to think about why the sky at night isn’t filled with starlight, we’d have figured this out years before Hubble actually did it.

And, that is why it’s important to ask stupid questions.

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This column originally appeared in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register.

Watch Mercury rise and fall all through May

2008-05-08T10:11:00.000-07:00

Watch Mercury rise and fall all through May
by Dave Adalian

If you go outside about half an hour after sunset tonight and look just above the western horizon where the sunburned sky has yet to fade you’ll find bright pink Mercury, fastest of the planets, shining in the Sun’s wake.

Elusive Mercury--the smallest of the planets at 3,032 miles wide--is putting in its best appearance of 2008 during May. But, you’ll still need to be quick to see it.

Just 800 miles wider than Earth’s moon and never further than about 36 million miles from the Sun, Mercury is difficult to find until the sun is far enough down. By then, though, the time for viewing is short.

When you find it, you’ll notice the messenger of the gods carries a distinctly reddish hue, but it’s an illusion. Mercury, which is similar in size to our moon, is also about the same color, and Mercury, too, is covered in thousands of impact craters that bear witness to our Solar System’s violent past.

Mercury’s ruddy tint, however, is an artifact of the air, which distorts the planet’s color as the light from so far away travels through Earth’s dust-filled atmosphere.

If you look at Mercury through a telescope, you’ll notice it also shares another trait with the Moon: it goes through phases. Right now, the Iron Planet--so called because it has a massive iron core larger even than Earth’s--is about 60 percent lit. But, it’s waning, and by the middle of the month it will be just 25 percent illuminated.

At the same time, however, Mercury is also coming closer to Earth, and so while its dark side comes into view it will also seem to grow larger.

As you watch night to night, notice that Mercury trails a bit further behind Sol for the first few days. Around midmonth, Mercury will stop drifting away from the sun, then after a couple of days will start falling back sunward. A week later it will take the keenest of eyes to detect Mercury in the afterglow of twilight, and by the end of the month there’s no chance of seeing it at all.

While Mercury is invisible to us back on Earth, it will be rounding the sun on an inside track then emerging on the morning side. But, it won’t be visible to early risers until late June. It will be easy to find about half an hour before dawn on July 1 when it’s paired with the thinnest sliver of an almost new moon.

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This column originally appeared in the Visalia Times-Delta and Tulare Advance-Register on May 8, 2008.

A Week of Wintertime Planet Watching

2008-01-23T23:25:00.000-08:00

A Week of Wintertime Planet Watching

by Dave Adalian

In the last hour before the Sun comes up tomorrow, the constellation Sagittarius will just be rising above the horizon in the southeast. There among the stars of the Archer, which are usually seen on much warmer summer evenings, will be a pair of bright planets racing toward conjunction on the first day of February.

A conjunction, of course, is a coming together, and this meeting of wanderers will be an especially close one. On Friday morning at about 6 a.m. Venus will be almost directly southeast and easy to find as the brightest thing in the sky besides the nearly full moon. Down, to the left about seven degrees away and not nearly as bright as Venus, early risers will spot Jupiter.

For the next week the two heavenly bodies will drift closer to each other, moving together about a degree each day as Venus’s orbit brings it seemingly closer to the sunrise and Jupiter. By Monday morning, the gap between the two will have closed to just four degrees, and those who haven’t been making daily checks will notice a huge difference since their last look.

As the week continues the goddess of love and her sire will make their way toward a father and daughter reunion in the early twilight of Friday, Feb. 1 when the pair will be separated just six-tenths of a degree. This is only slightly larger than the width of a full moon.

The Moon that morning will be a very thin crescent at the end of its cycle, riding nearby in the stars of Scorpius. It will not be alone. Close by to its left will be Antares, the red heart of the scorpion.

Those who like to sleep in won’t be left out of the planet viewing, and they don’t have wait for next week to get started either. Tonight by about 9 o’clock, Mars will be almost directly overhead, still glowing brightly after making a close approach in late December.

Surrounding the Red Planet are the six bright stars of the Winter Circle. Going clockwise: dazzling Sirius, white Procyon, Pollux with its dimmer twin Castor, lonely Capella, red Aldebaran and brilliant Rigel.

Below them all in the east nestled in the stars of Leo the Lion sits the Moon, just two days past full. Perched there above it, glowing a golden yellow, is ringed Saturn finally making its return to nighttime skies.

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This column originally appeared in the Visalia Times-Delta and Tulare Advance-Register on Jan 24, 2008.

Planetarium Show January 11!

2007-12-20T11:50:00.000-08:00

"The Hero, the Lady and the Stars of Winter" will be shown at the Sam B. Pena Planetarium, 2500 W. Burrel Ave., Friday, Jan. 11, at 7:30 p.m., with stargazing with members of the Tulare Astronomical Association to follow.

Tickets are $4 for adults and $3 for children, and are available at the planetarium's office or by calling 737-6334.

Click here for the Tulare County Office of Education's Impact Center, home of the Pena Planetarium.

Click here for a map of the planetarium and observing site.

The Week Before Christmas: A Holiday Visit from Mars

2007-12-18T23:23:00.000-08:00

The Week Before Christmas: A Holiday Visit from Mars
by Dave Adalian

‘Twas the week before Christmas,
When up in the sky,
There appeared a bright star
Out of place to my eye.
It was in the wrong space,
With the wrong color, too,
And it didn’t twinkle,
Which is something stars do.

It had a hue like a campfire
And was awfully bright;
It outshone all the other stars
With the strength of its light.
“Could that be Rudolf?”
I wondered out loud.
“Do you think?” came an answer;
I was drawing a crowd!

It was then I remembered
That I’d seen this before:
It was fourth planet Mars
Come to knock on our door--
It’s every two years,
Regular as a clock,
Mars crosses the heavens
To visit Third Rock.

“That’s not Santa,” I said,
Pointing up at the sky.
“It’s the Red Planet,
And I’ll tell you why!
All warm autumn long
We’ve watched it grow nearer,
And now cold winter skies,
Make it seem even clearer.

“That planet a-shining
Way up high near’ to Heaven
Is now at its closest
For two-thousand-and-seven.
So bundle up Christmas Eve,
And step out after dark.
You’ll see quite the sight,
One to make you remark!

“It’ll shine in the east,
Bright fiery Mars hanging low,
And right along side it
The Full Moon will glow--
All night long the War God
Along with Luna will fly
Accompanying St. Nicholas
Away up there in the sky!

“As you stand struck with awe
At that celestial wonder
If your thoughts back to Earth
For a moment do wander
I’ll seize on the instant
For there’s something to say:
I most sincerely do wish you
A wonderful winter holiday!”

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This column originally appeared in the Visalia Times-Delta and Tulare Advance-Register on Dec. 20, 2007.

Meeting Wednesday, Planetarium Show & Star Party Friday

2007-12-01T16:59:00.000-08:00

Planetarium Show & Star Party Friday

"The Lady, the Hero and the Stars of Winter" premieres this Friday, Dec. 7, at the Pena Planetarium, 2500 W. Burrel Ave. in Visalia, at 7:30 p.m., with stargazing with members of the Tulare Astronomical Association to follow. The show will run again Friday, Jan. 11, also at 7:30 p.m.

Tickets are $4 for adults and $3 for children, and are available at the planetarium's office or by calling 737-6334. Click the link on the upper right side of this page for more information.

TAA Business Meeting Wednesday Night

The Tulare Astronomical Association will hold its monthly business meeting at 6 p.m. on Wednesday, Dec. 5, at the offices of the Delta Vector Control District, 1767 W. Houston Ave. in Visalia. This is a non-viewing meeting.

A Long Look into the Distant Past

2007-11-08T18:00:00.000-08:00

A Long Look into the Distant Past
by Dave Adalian

How far can the human eye see?

The question sounds like something a Zen master might ask a student to bring him enlightenment, but unlike puzzling over the sound of a single hand clapping, this question actually has an answer.

Two and a half million light years, about 14.7 billion billion miles, is as far as the human eye can look.

That’s how far the empty void between our galaxy, the Milky Way, and our nearest large neighbor, the Great Andromeda Galaxy, stretches, and the Great Andromeda Galaxy is the farthest thing the human eye can see without the help of a telescope.

That distance is also as far back in time as we can look.

To find the Great Andromeda Galaxy find a dark sky away from city lights on a moonless night during late fall or early winter and look almost overhead for the Great Square of Pegasus, a huge square formed by four bright stars. Then look northeast for an M-shaped group of stars in the constellation Cassiopeia and imagine a line between the brightest of these stars and the brightest star in the Great Square. Just east of that line about two-thirds of the way along it in the direction of Pegasus you’ll see the bright glow that is the light of the Great Andromeda Galaxy.

That faint and distant glow left its home galaxy 2.5 million years ago, long before modern human beings walked the Earth. When we look at Andromeda, we are looking back in time and seeing that galaxy not as it is today but as it was in the long ago past.

We’re also seeing almost exactly what a person living on a planet in the Andromeda Galaxy sees he when looks up on a clear and moonless night and gazes back across the empty void and the endless years at the Milky Way, since the two galaxies are very similar in size and form with each containing billions of stars arrayed in vast and sweeping spirals.

If the sky is dark enough and one’s eyes are good enough, the Great Andromeda Galaxy appears huge, stretching about five degrees across the sky or 10 times the width of a full moon.

What isn’t obvious when looking at Andromeda is that it and the Milky Way appear to be on a collision course, moving toward each other at more than 250,000 mph. Not to worry, however. Even at that speed if the two do collide it won’t be for another three billion years.

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The Tulare Astronomical Association and the Tulare County Office of Education will present The Hero, the Lady and the Stars of Early Winter, a planetarium program written and narrated by Starry Nights columnist Dave Adalian Dec. 7 and Jan. 11 with a free star party to follow. For details, check the Starry Nights blog at starry-starry-nights.blogspot.com or the Pena Planetarium website at www.tcoe.k12.ca.us/ImpactCenter/Planetarium.shtm

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This column originally appeared in the Visalia Times-Delta and Tulare Advance-Register on Nov. 22, 2007.

TAA to Meet Nov. 7

2007-11-06T11:15:00.000-08:00

The Tulare Astronomical Association will hold its monthly business meeting at 6 p.m. on Wednesday, Nov. 7, at Amigos Restaurant, 5113 W. Walnut Ave. in Visalia. This is a non-viewing meeting.

We'll have news from the Sequoia Riverlands Trust regarding the Dry Creek Drive site.

UC Berkeley Astronomy Lectures Online

2007-10-13T14:12:00.000-07:00

As a public service, University of California, Berkeley is allowing everyone streaming access to webcasts and podcasts of the lectures of several of its classes, including two classes entitled Introduction to General Astronomy, via Real Player. The course lectures are also downloadable.

To view them, go to http://webcast.berkeley.edu/ and select the "/courses" link. The two astronomy courses are listed as Astro 10P and Astro C10/LS C70U.

Early Autumn is the Season of the Moon

2007-10-01T18:21:00.000-07:00

Early Autumn is the Season of the Moon
by Dave Adalian

In ye olde days, when folks made their livings off the land, the Moon was an invaluable tool for bringing in the harvest when days turned short just as the crop came ripe.

Light the face of the full moon reflects, even though it’s much dimmer than the Sun’s, is enough to swing a scythe by. It allowed farmers to work well past sunset and get food they and their animals needed to survive a long, harsh winter into storage before wet and freezing weather rotted it in the fields.

While most of us toil in air-conditioned surroundings these days, echoes of earlier times are still with us in the names we give each month’s full moon and in the myths that surround our satellite.

The full moon of September, when the last of the corn is being cut and the hay mowed, is the Harvest Moon, the one that helped our ancestors see their way through the night, and it still carries that honorific today. October’s full moon, rising when the fields are cut to stubble and prey has nowhere left to hide, is still called the Hunter’s Moon in these modern days of supermarkets.

The other thing autumn’s moons carry with them is the myth they loom larger in the sky than moons do the rest of the year. It isn’t so.

The Moon is always the same size, and though its orbit isn’t a perfect circle -- meaning it’s sometimes slightly closer to Earth than at other times -- the difference isn’t noticeable to the naked eye. But, when the Moon is close to the horizon, it appears bigger than when it’s high overhead. A trick of the eye that’s perhaps more noticeable this time of year when more people are out and about at moonrise.

On Friday, the Moon will be at first quarter, meaning its western half will be illuminated, and it will be due south at sunset. Watch as it grows fatter and moves east from night to night until it reaches fullness seven days later.

That night, when the full moon rises over the Sierra, notice how large it looks, then measure it by holding your hand at arm’s length with a pinkie extended. Half the tip of your little finger should cover it.

Come back outside closer to midnight, when Luna is riding high, and measure her again. She’ll look much smaller up among the stars, but your finger will tell you the difference is all in your head.

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For more on the names of full moons, check out this article from the Old Farmer's Almanac.

What phase is the Moon in tonight? Click here to find out.

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This column appeared originally in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on Oct. 18, 2007.

Planetarium Show this Friday!

2007-10-01T11:13:00.000-07:00

The show I've written for the Sam B. Pena Planetarium, 2500 W. Burrel Ave., premieres this Friday, Oct. 5, at 7:30 p.m., with stargazing with members of the Tulare Astronomical Association to follow. The show will run again Friday, Nov. 2, also at 7:30 p.m.

Tickets are $4 for adults and $3 for children, and are available at the planetarium's office or by calling 737-6334.

Click here for the Tulare County Office of Education's Impact Center, home of the Pena Planetarium.

Click here for a map of the planetarium and observing site.

Do Some Simple Science!

2007-09-28T21:42:00.000-07:00

Here's a chance to do some real science while stargazing. The Great Worldwide Star Count is a project aimed at finding out how much light pollution has dimmed our view of the stars around the planet. This simple collaborate effort of "citizen scientists" requires just a bit of effort and will help us get a better picture of our night skies around the planet.

Click here for The Great Worldwide Star Count.

Mars Really Is Looming Large

2007-09-14T07:52:00.000-07:00

Mars Really Is Looming Large
by Dave Adalian

Used to be Mars was a hot topic of astronomical conversation only once every two years.

That’s how long it takes Earth to swing around the Sun and catch up with the fourth planet of our solar system, which itself is racing along in the same direction.

These days, thanks to the Internet, Mars reappears every August, and it’s always going to be the size of a full moon when it arrives. At least that’s what emails my readers forward to me say. The questions they usually send along with these emails run like this:

“I know this can’t possibly be true, but I wanted to know for sure so I don’t miss it if it is, so is it?”

No.

Welcome to the annual Mars hoax, an unsinkable chain letter saying Mars will appear the same size as the full moon in August. The people who email know this can’t be right, but the allure of Mars is such they want it to be. So do I. But, alas, it isn’t going to happen. Never.

But the god of war will be here soon, and this year, Santa won’t be the only thing dressed in red, white and black showing up on Christmas Eve.

Mars reaches opposition on Dec. 24. It will rise as the Sun sets and stay up all night. It does this because the red planet is opposite the sky from Sol, which is what “opposition” means.

It also means the time to start watching Mars is now.

The reason my hopeful correspondents know Mars isn’t going to be the size of the full moon is we’d start seeing it looming ridiculously large months before the big show. The same is true for this lesser but at least real apparition: Mars is already showing itself, rising around 11 p.m. between Orion and Gemini and getting high enough for good viewing by 1 a.m.

And, Mars isn’t sitting still. Right now Earth and the red planet are zooming toward each other at around 25,000 mph. In October 2006, Mars was on the other side of the Sun from Earth, 243 million miles away. Now, a year later, Mars is just over 90 million miles distant, and the gap is shrinking fast.

Between now and Christmas Eve, Mars will come 35 million miles closer to Earth and brighten by a factor of four, all the while rising earlier and earlier each night. Just step outside and you can watch it happen.

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The Tulare Astronomical Association and the Tulare County Office of Education will present The Stars of Autumn, a planetarium program written and narrated by Starry Nights columnist Dave Adalian on Oct. 5 and Nov. 2 with a free star party to follow. For details, check the Starry Nights blog at starry-starry-nights.blogspot.com or the Pena Planetarium website at www.tcoe.k12.ca.us/ImpactCenter/Planetarium.shtm.

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This column appeared originally in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on Sept. 20, 2007.

Moon 2.0

2007-09-13T11:30:00.000-07:00

Google and the X Prize Foundation are sponsoring two $30 million purses to the first two teams to put a roving robot on the Moon. There are bonuses for discovering water ice in the permanently dark craters near the lunar south pole, surviving the long lunar night and visiting the remains of past lunar exploration. Blast off!

THE GOOGLE LUNAR X PRIZE HOMEPAGE

TAA at the Pena Planetarium

2007-09-10T15:41:00.001-07:00

I've written a script for a planetarium show at the Tulare County Office of Education's Pena Planetarium, which will be shown the nights of Oct. 5 and Nov. 2. The show will cover some of the constellations of autumn, specifically those in and around the Summer Triangle and Hercules. Keep an eye on this space or check the planetarium's website for details.

We'll be setting up our telescopes for a look at some of the objects mentioned in the program after the show is over.

The Pena Planetarium at the TCOE Impact Center

TAA to Meet Sept. 6

2007-09-05T18:05:00.000-07:00

The Tulare Astronomical Association will hold its monthly business meeting at 6 p.m. on Thursday, Sept. 6, at Amigos Restaurant, 5113 W. Walnut Ave. in Visalia. This is a non-viewing meeting.

Map to meeting location.

Sky Dragon Swallows the Moon

2007-08-06T18:44:00.000-07:00

Sky Dragon Swallows the Moon

by Dave Adalian

In the early morning hours of Tuesday, Aug. 28, the Moon will be swallowed by a great sky dragon that will slowly consume it, turning the lunar disk a deep blood red.

The Moon will not sit well on the dragon’s stomach, and 90 minutes later it will escape back into the sky to the thunderous noise of exploding firecrackers, the clash of pots and pans and the hoarse and angry screaming of humans shouting to frighten the hungry dragon away.

At least that’s the way it would happen if this were ancient China. If we were among the Vikings, it would be pretty much the same thing, with a wolf eating the Moon instead of a dragon. For the Serrano Indians, it’s the spirits of the dead doing a bit of celestial binging and purging.

The reality isn’t nearly so fanciful, but it’s at least as dramatic.

Usually once or twice a year--but sometimes thrice or even not at all--the Earth, Moon and Sun will for a brief few minutes line up so Earth’s shadow falls across the Moon, nearly blotting it from the sky. But, because Earth’s atmosphere bends some of the sunlight, the shadow is never completely dark, giving the Moon a red or brown tint during totality.

On the morning of Aug. 28, the Moon will begin to darken at a few minutes before 1 a.m., as it enters Earth’s penumbra, the lighter ring of shadow surrounding Earth’s darker inner shadow, the umbra.

Just moments after the Moon is entirely within the penumbra, a minute or two after 2 o’clock, its leading edge will enter the darker umbra and begin to take on the ruddy aspect of blood.

For almost an hour the Moon will fall deeper into the umbra until by 3 a.m. it will be entirely consumed by darkness.

The only way out for the Moon is through, a journey that will take some 90 minutes to complete. The Moon will reemerge beginning about 4:25 a.m., exiting the umbra entirely an hour later.

The Moon will still be in the lighter penumbral shadow for another hour, finally escaping Earth’s shadow into the pale blue light before dawn, only a scant few minutes before the Sun rises on the opposite side of the sky and the Moon sinks into the west.

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This column appeared originally in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on Aug. 23, 2007.

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For a more technical discussion of the Aug. 28, 2007 lunar eclipse, along with charts and times, visit NASA's Eclipse Home Page.

TAA to Meet Aug. 2

2007-07-28T00:47:00.000-07:00

The Tulare Astronomical Association will hold its monthly business meeting at 6 p.m. on Thursday, Aug. 2, at Amigos Restaurant, 5113 W. Walnut Ave. in Visalia. This is a non-viewing meeting.

Falling Stars on Hot August Nights

2007-07-14T12:47:00.000-07:00

Falling Stars on Hot August Nights

by Dave Adalian

About every 130 years or so, Comet Swift-Tuttle swings by Earth, circles the Sun, then heads back out into the dark, cold recesses of the Solar System.

As it sails along, the comet loses bits of itself, leaving a trail of tiny specks of ice and rock in its wake. As the years go by these comet crumbs spread out along Swift-Tuttle’s orbit into a huge doughnut-shaped cloud. Then, each August, Earth dives into that cloud, and the result is the annual Perseids meteor shower.

The Perseids are the year’s most reliable shower, with only a dud or two in the last decade. The 2007 show isn’t expected to bring the 400 or more meteors an hour seen in the early 1990s but away from city lights under a transparent sky, 80 to 100 an hour during the peak isn’t an unreasonable expectation.

The 2007 Perseids reaches an apex the night of August 12-13, with the greatest number of meteors predicted to fall between 10 o’clock and a half an hour after midnight.

The new moon will be absent from the sky, which is perfect for a meteor watch. Unfortunately, the peak’s timing is a bit off.

Best time to see meteors is around 2 a.m., when the sky overhead is facing forward with respect to Earth’s motion around the Sun, making it just like a car’s windshield. There are always more bug-splats on the front window than on the sides, and during the peak, the sky here will be like the side window of a car. So, like bug-splats on a side window, there will be fewer meteors but the ones we do see will be more like spectacular streaks than splats.

These meteors, known as earthgrazers, will come blazing in from the northeast, where the constellation Perseus--which gives the shower its name--will be rising, then shoot across the sky toward the opposite horizon.

Fortunately, the Perseids are very active around the peak. Rates of 40 meteors an hour the nights before and after are a real possibility. The Perseids is also a long shower that began July 17 and lasts through Aug. 24.

But, the best night for Perseids watching will be the night of the peak, and meteors will still be falling when 2 a.m. rolls around. And for those who stay up late, there’s the bonus of seeing Mars rise among the meteors around 1 a.m.

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This column appeared originally in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on July 26, 2007.

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For the International Meteor Organization's 2007 Meteor Shower Calendar, which includes technical discussion of the showers and sky charts, click here.

TAA Monthly Meeting July 5

2007-07-03T18:54:00.000-07:00

The Tulare Astronomical Association will hold its monthly meeting on Thursday, July 5 at 6 p.m. at 4423 E. Sycamore Ct. in Visalia. All interested parties are invited to attend.

Directions:

FROM HWY 99: GO EAST ON HWY 198.

EXIT ON LOVERS LANE – TURN LEFT.

TURN RIGHT ON HOUSTON AVE.

RIGHT AFTER YOU PASS SOL ROAD, LOOK FOR TALL TREES ON RIGHT THAT IS COMSTOCK (EASTOAK ESTATES SUBDIVSION) TURN RIGHT IMMEDIATELY.

GO TO NEXT TO LAST STREET, TURN LEFT ON SYCAMORE COURT.

WE ARE ON THE RIGHT SIDE OF SYCAMORE.

Summer of the Planets Continues

2007-06-25T13:05:00.000-07:00

Summer of the Planets Continues
by Dave Adalian

The brightest of the planets will meet the most beautiful of the planets in the west this weekend.

Since the start of the year, dazzling Venus has been hanging in the western sky after sunset. Long night after long night, the evening star grew brighter and higher in the sky until it reached its peak in the much shorter nighttimes earlier this month.

Now, the goddess of love has begun her decent back into the overbearing glare of the sun, but before she fades away she’ll be visited by another of the planets, the one considered by many as the Solar System’s loveliest.

Six months ago, when Venus was making her first tentative appearance as daylight faded in the west, Saturn was becoming prominent in the east. As the months passed, nightfall found Saturn further west each night until it was hanging low in the western sky at sunset.

While Saturn was creeping across the celestial sphere, Venus waited patiently. The two will finally meet this weekend.

When the sun goes down tonight, Venus will be where it has been all year, following the sun as it sets in the west. About an hour after sundown, Venus will be unmistakable as the brightest thing in the western sky. Above and to its left you’ll find a much dimmer Saturn.

Though Saturn, at 75,000 miles in diameter, is much larger than 8,000-mile-wide Venus, Venus is much closer to Earth, a mere 50 million miles away compared to a whopping 925 million miles for the more distant ringed planet.

Tonight, the two planets will be less than 2 degrees apart, about twice the width of the tip of your little finger held at arm’s length or about four times the width of a full moon.

By Friday night, the pair will have closed to just 1 degree, close enough you will be able to hide both of these worlds behind your little finger. Fittingly, on Saturday, Saturn’s day, the two will be at their closest, about three-quarters of a degree apart.

The two remain less than a degree apart as Saturn slips by on Sunday, then they’ll be just more than a degree apart when Monday comes to a close.

Keep watching the pair as the grow apart and on July 16 you’ll be rewarded with the spectacular grouping of Venus, Saturn, the moon and the bright star Regulus.

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This column appeared originally in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on June 28, 2007.

TAA July Meeting

2007-06-12T17:46:00.000-07:00

At the TAA business meeting in June, it was decided to hold monthly meetings to conduct club business and discuss the latest developments in astronomy. The July meeting, open to all interested persons, will be held at 6 p.m. on Thursday, July 5. The location will be announced.

THIS WILL BE A NON-VIEWING MEETING.

TAA Annual Business Meeting June 5

2007-05-31T14:41:00.000-07:00

NOTE CORRECTED ADDRESS!

The Tulare Astronomical Association will hold its annual business meeting on Tuesday, June 5 at 6 p.m. at 3124 W. Hillsdale Dr. in Visalia. All interested parties are invited to attend.

Map to the meeting.

Mars Joins Planetary Parade

2007-05-28T13:50:00.001-07:00

Mars Joins Planetary Parade
by Dave Adalian

In my last column, I took you on a tour of the naked-eye planets, starting at sunset with elusive Mercury and ending in the early morning hours with blue Neptune. This time, another member of the solar system entourage joins the show while two others put in their best appearances of the year.

Tiny Mercury, a rocky planet just 3,000 miles wide, sits closest to the Sun, making it a bit of a challenge to view. But on Saturday, Mercury will be as far as it ever gets from the Sun as seen from Earth, a condition known as greatest elongation.

While Mercury, swift-footed messenger to the gods, will be visible for another couple of weeks, now, before it falls back into the fiery skirts of Sol, is the best time to see it. Look a bit north of dead west about an hour after the Sun retires to find it.

Don’t confuse Mercury with its brighter sister, Venus, also prominent in the west after sundown. This brightest of planets reaches greatest elongation one week after Mercury, but being farther from the Sun rides higher in the sky. Venus is a bright white, while Mercury, seen through more of Earth’s atmosphere, appears pink. Beside Venus are the twin suns of Gemini, Pollux and Castor.

Imagine a line through Mercury and Venus and follow it up the sky about the same distance as the current separation of Mercury and Venus. There, you’ll find Saturn, still sitting like a cosmic ball of yarn before the paws of Leo the Lion.

Saturn and Venus are headed for a close conjunction toward the end of June, so watch them night-to-night as grow ever closer together. Both will be gone from the sky by late July.

While the western trio is riding high, the King of Worlds, Jupiter, is rising in the southeast. By 11 o’clock it is well placed for viewing.

By 3 a.m., Neptune is high enough to be seen--if the sky is dark enough--but a chart is necessary to find it. (See link to a finder chart below.)

About an hour and a half later, just before dawn’s probing fingers creep above the horizon, look east to find Mars’ shining ruddily.

The Red Planet bears watching over the next year as it sweeps toward a close pass of Earth on Christmas Eve then fades back into the distant reaches of the Solar System, not to return again until mid-2009.

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This column appeared originally in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on May 31, 2007.

Finding Neptune (and Uranus, too!)

2007-05-23T17:50:00.000-07:00

Here's a link to a set of charts to help planet-hunters find the dimmest of naked-eye planets, Neptune. The charts are also good for finding Uranus, but you'll need at least a pair of binoculars to see it.

http://www.rasnz.org.nz/SolarSys/UranNept.htm

Thanks to the Royal Astronomical Society of New Zealand for the charts.

Conjunction Images

2007-05-20T13:58:00.000-07:00

Here's a shot of Venus and the new moon I took from my backyard in Visalia, Calif. around 8:45 p.m. PDT on May 19, 2007.

http://farm1.static.flickr.com/195/505508659_ef30c03152_b.jpg

Here's the best of the snaps I got of the Mercury-Moon conjunction two nights earlier from a local park about 8 o'clock:

http://farm1.static.flickr.com/224/505499552_1e4120f52c_b.jpg

Planetary Tour Starts Tonight

2007-05-09T17:46:00.000-07:00

Planetary Tour Starts Tonight (May 3, 2007)
by Dave Adalian

You may be one of the many people who found themselves with a sudden interest in the stars and planets after the announcement last month of the discovery of a possibly earthlike planet just 20.4 years away.

If the first earthlike planet we’ve found is this close, imagine how many others there must be in a galaxy bigger than 100,000 light years across. Suddenly, the possibility we’ve got neighbors who could be peering back at us with their own telescopes from their own backyards becomes tantalizingly real.

The star the newly discovered planet orbits, Gliese 581, is a dim red dwarf in the constellation Libra, and it doesn’t do much for the imagination, especially if you’re a newly minted planet-gazer looking for something to hang your dreams of space upon.

But, I’ve got good news for you would-be space cases: there is a bevy of much closer planets you can see with your own eyes starting tonight.

If you look west tonight just after sunset, you’ll find the brightest of the naked-eye planets, brilliant Venus, shining like a jewel. This sister planet to Earth will be spending the entire summer as the evening star.

To find the largest of the local planets, you’ll have to stay up tonight until the Moon rises around 11 o’clock. When it makes its way skyward, it will sit just to the right and below Jupiter.

Though you’ll need a telescope if you want to see it, the recently demoted dwarf planet Pluto is to Jupiter’s left. The bright red star to the right and above the Moon is Antares.

When Jupiter and the Moon are just entering the sky, Saturn will be in the opposite direction, sitting well above the horizon to the west in the constellation Leo.

The dimmest of the naked-eye planets, sea-blue Neptune, is rising in the early morning these days, around 3 o’clock. It takes a dark sky to see Neptune, but you can get a very good idea of its general location when the Moon rises near it on the morning of May 10.

On the evening of May 17, the Moon will be back in the west just after sunset, this time with elusive Mercury just below it. The Moon will be the barest slice, just a few hours past new, and may itself be difficult to find.

Finish your springtime planetary tour on May 19 when Venus and the Moon meet in an incredibly close pairing that’s sure to dazzle.

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This column appeared originally in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on May 3, 2007.

Venus Visits Star Sisters

2007-03-29T20:26:00.000-07:00

Venus visits star sisters

by Dave Adalian

If you go out tonight around 8:30 p.m. and look west you’ll find white Venus shining brilliantly back at you from above the horizon.

Venus will be about 20 degrees high or four times the width of your fist held at arm’s length with knuckles raised and thumb tucked. Not quite that same distance above Venus you’ll discover a cluster of blue-white stars in the shape of a tiny dipper. They are the Pleiades, or Seven Sisters, and they’re on course for a close pass with Venus that will be a stargazer’s delight.

Of course their apparent proximity will be just an illusion. Venus is never farther than 160 million miles from Earth, while the Seven Sisters are some 400 light years away.

And there are a lot more than just seven sisters. Most folks see just six of the Pleiades with their naked eyes. Viewing with binoculars drives the number much higher, and a telescope reveals 100 or so suns blazing away in a cluster that fills a spherical area 14 light years across.

The much smaller but brighter Venus is a dainty 8,000 miles wide, just a deep breath thinner than its twin Earth.

While these celestial ladies look to be a fair distance apart at the moment, over the next couple of weeks they’ll pull together until they’re a scant 2.5 degrees separate, close enough an extended hand could hide them.

It just so happens Venus will seem to stand almost perfectly still with respect to the Sun over the next few weeks, so most of the effect we’ll be witnessing is the stars shifting as the days of spring pass and Earth races through its orbit at some 67,000 miles an hour.

The change will be subtle at first. It takes until Tuesday for the Pleiades to close to within 10 degrees of Venus, but then the pace picks up and the distance will be 5 degrees by Saturday, April 7, and only 4 degrees the next night.

The gap shrinks about half a degree a night until Venus and the Seven Sisters reach their closest on Wednesday, April 11. The two will still be a mere 2.75 degrees apart the next night and only 3 degrees distant the night after that.

Venus will still be just 10 degrees above the Seven Sisters on Thursday, April 19, when a thin slice of crescent moon settles between them.

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This column originally appeared in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on March 29, 2007.

Winter Skies Are Tricky

2007-02-15T14:12:00.000-08:00

Winter Skies Are Tricky
by Dave Adalian

Icy February nights aren’t well suited to stargazing, but this winter the Solar System is putting on an early evening show that will have planet hunters back safe and warm at a reasonable hour.

But, when those would-be planet seekers trudge home they may feel frustrated as the skies are presenting a trio of difficult challenges this month.

In early evening since the year began the most brilliant of the planets, Earth’s twin Venus, has shone like a searchlight in the western sky in the hours after sunset. While there’s nothing difficult about finding this fiery gem after dark, those who like a real challenge can search for cloud-covered Venus winking in the deep blue while the Sun is still up.

To find any planet when the Sun is still above the horizon, it’s important to know exactly where to look. The easiest way to know where Venus will be is locating it just after sunset the night before a daytime search.

If that’s too easy, the try looking for Venus about 10 degrees to the left of the Sun--that’s about two widths of a fist held at arm’s length--and about 25 degrees above it--about five fists’ worth. Stand in a shadow to cut down on glare, and do not look directly at the Sun for any reason.

Despite any frustration this may cause, do not attempt to aid a daytime search with binoculars or a telescope because even a brief accidental view of the Sun can cause permanent eye damage or even blindness.

The next challenge has to be completed before Mercury moves back into the Sun’s glare this weekend. The innermost planet has just passed greatest elongation, when it appears farthest from the Sun, and it is visible just above the horizon right after sunset. Because Mercury never rises far from the Sun, it can be difficult to find and many longtime amateur astronomers have never viewed it, making it a feather in the planet hunter’s cap.

The final February planetary challenge is on the other side of the sky, where Saturn is now rising as the Sun sets in the west. To find it among the stars of Leo, look a bright light that doesn’t shimmer like the rest of the stars. The full moon will remove any doubt of Saturn’s identity on March 1 when it rides beside it through the sky all night long.

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This column appeared originally in the Visalia (Calif.) Times-Delta on Feb. 15, 2007.

A Ring Fire in the Sky

2007-01-15T00:00:00.000-08:00

A Ring Fire in the Sky
by Dave Adalian

By far the brightest stars of the year are to be found in the skies on winter nights, glinting like shards of ice in the frozen heavens.

The brightest of the bright stand together early in the southeast, describing an enormous ring stretching from a hand’s breadth above the horizon to almost the top of the sky just an hour or two after nightfall.

Lowest and brightest among these jewels of the young year is Sirius, the Dog Star, which shines, glinting and shimmering with spikes of every color as it dances in the turbulent air, directly to the southeast. Brightest of all stars we can see from Earth at magnitude -1.5, Sirius marks Canis Major, faithful hound of Orion the Hunter.

Orion is home to Rigel, another blue-white gem that is the Hunter’s foot just above and to the right of Sirius. A dimmer star than dazzling Sirius, magnitude 0 Rigel--seventh brightest in the sky--only fails to outshine Sirius because it is more than 100 times farther away.

To the left of Rigel and inside the ring of winter gems is Betelgeuse, a magnitude 0.5 red star that ranks ninth among its peers.

Continuing on around the ring of fire find angry Aldebaran, the orange-red eye of Taurus the Bull. This 13th brightest star shines at just under magnitude 1 and is directly above Orion’s head as the Bull charges down upon the Hunter.

The highest point of the fiery ring is Capella, a yellow diamond of magnitude 0, sixth brightest of the stars in the sky. Capella is the she-goat and it rides across the sky carried in the arms of Auriga the Charioteer, a constellation that is itself a ring of stars.

Dropping back toward the horizon, look for the bright twins of Gemini, Castor and Pollux, directly below and slightly to the left of Capella. Orangish Pollux is merely the 16th brightest of the night’s stars, just dimmer than magnitude 1, but perhaps it seems to the eye to glow with more luster when aided by Castor, his nearby magnitude 1.5 brother.

Lower than the twins and seated between them and brightest Sirius is Procyon, another shining yellow-white gem. At a bit dimmer than magnitude 0, Procyon is the eighth brightest of the stars and the brightest of the tiny constellation Canis Minor, the lesser of Orion’s hunting companions.

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This column originally appeared in the Visalia (Calif.) Times-Delta in January of 2007.

Give the Gift of the Stars

2006-12-15T00:00:00.000-08:00

Give the Gift of the Stars
by Dave Adalian

If there’s someone on your holiday list who’s got stars in their eyes, then the gift of astronomy might be a perfect solution, and it can be done without breaking the bank.

The best way to start someone on the hobby of amateur astronomy is to get them out under the heavens with nothing but their naked eyes.

To learn the bright stars and the constellations they’ll need a set of star maps, which can be found in lots of places, either on their own in sky atlases or as part of a publication.

Atlases tend to be pricey and are definitely geared toward the experienced observer using a telescope, so for the beginner a better gift is a book or perhaps a magazine subscription.

Terence Dickinson’s Nightwatch: A Practical Guide to Viewing the Universe is an excellent title for would-be astronomers young and old. It includes a good set of simple maps as well as advice on getting started in the hobby and chapters on various aspects of the night sky such as planets, star clusters and galaxies.

For very young stargazers, Find the Constellations by H.A. Rey, author of the Curious George books, might be a better fit.

For someone who’s already read a bit about the hobby, a magazine subscription is a better idea. Both Astronomy and Sky and Telescope feature monthly calendars with sky charts and have the added bonus of articles on stargazing for all experience levels.

Buying a telescope is usually a personal experience for the amateur observer and isn’t something that should be done without lots of research, so I don’t recommend it as a gift idea. But, a good sturdy pair of binoculars can make an excellent first set of optics for beginning stargazers.

Binoculars are rated by a pair of numbers separated by an X. The first number is the magnification, and the second is the size of the objective lenses. To be useful for astronomy, binoculars should be at least 7x35s--they magnify objects by seven times and have lenses 35mm wide. Better would be a pair of 10x50s, which can usually be had at local department and sporting goods stores for $20 to $40.

And if the stars in your would-be observer’s eyes fade, binoculars have dozens of other terrestrial uses, from bird watching to viewing sporting events and won’t go to waste.

If none of this appeals then remember that it’s cold on those long winter watches after dark. The gift of a warm hat or a thick sweater also suits those who spend their nights under the stars.

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This column originally appeared in the Visalia (Calif.) Times-Delta in December of 2006.

Clouded Out!

2006-11-10T15:58:00.000-08:00

Looks like we're in for a weekend of cloudy and possibly rainy weather, which means no star hunting tonight (Friday, Nov. 10). Enjoy the wet stuff folks, and maybe we'll get back to star gazing next month.

-- Dave

Meteor Magic on Demand

2006-11-10T13:29:00.000-08:00

Meteor Magic on Demand
by Dave Adalian

Almost everyone has been dazzled by the sight of a meteor burning its way across the dark heavens on a starry night.

There’s something magical about those little bits of dust no bigger than a grain of rice superheating the atmosphere as they come rushing at speeds dozens of times faster than sound.

The only trouble is you can never tell when you’ll see a shooting star.

Some may say not knowing when a meteor will fall from the sky is part of their particular magic. I happen to disagree.

Even when you know there is likely to be a meteor shower, as there should be Saturday night, Nov. 18, when the Leonids reach their annual peak, the magic is still powerful.

Those who wish to experience this bit of scheduled magic will find the shower’s peak timed slightly too early for our side of the globe, but there should still be a good show.

The Leonids, which take their name from the constellation Leo the Lion where they appear to originate, should reach highest concentration at about 8:45 p.m.

While it will already be plenty dark by then, Leo will not have risen above the eastern horizon and won’t until around 2 a.m., which is the best time to see the Leonids.

Even so, at the time of the peak observers here may get a special treat, an abundance of “Earth grazers”, meteors that shoot from one side of the sky to the other. The number of meteors to be seen is impossible to say, though a more realistic count is 10 to 25 an hour during the course of the entire night.

That number, of course, describes what might be seen under ideal conditions of a dark sky with Leo well above the horizon at the moment of the shower’s peak.

While there won’t be a high flying lion at peak, we can maximize our meteor potential by seeking darker skies than those in our backyard. Falling star seekers should head to the hills or at least well outside the city limits as urban viewers will miss three quarters of the show.

Wherever you go to view the Leonids, bring along a chair that will let you comfortably scan the sky about 60 degrees above the horizon, and point your toes toward the darkest part of the night.

Remember to dress warmly for an extended stay in the cold, and don’t forget the warm drinks and snacks.

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Join the star hunters of the Tulare Astronomical Association this Friday night, Nov. 10, 7-9 p.m. for a look at the stars of late autumn at the Arthur L. Purcell Observatory, 9242 Ave. 182, 2.1 miles west of Highway 99 and south of Tulare. Information and directions: http://starry-starry-nights.blogspot.com/.

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This column originally appeared in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on Nov. 9, 2006.

The Lion, the Moon and Saturn

2006-10-25T17:35:00.000-07:00

The Lion, the Moon and Saturn
by Dave Adalian

Starting before dawn on Monday morning, the Moon will enter the belly of the beast.

In the early morning, around an hour or so before sunrise, the slender crescent of a waning moon will lie due east, sitting like a cosmic ball of yarn between the paws of Leo the Lion.

But, it won’t be alone. Just below and the to the right of the Moon will be the bright, yellow ringed planet Saturn, making it a cinch to find this second largest of the eight planets.

While it will seem the Moon and Saturn are so close they could reach out and touch one another, in reality the Moon is just 220,000 or so miles from Earth, while Saturn is more than 900 million miles away at present. And, while Saturn, a simple pinprick in the sky, seems much smaller than our 2,000-mile-wide Moon, it is actually 75,000 miles across.

In fact, Saturn’s rings are the largest structure in the Solar System besides the Sun itself. Measured side to side, Saturn’s ring system is an impressive 155,000 miles wide.

On Tuesday morning, a still thinner Moon will head deeper into Leo, sitting just below the lion’s brightest star, Regulus. The word Regulus is Latin for “the prince,” and is sometimes referred to as Cor Leonis, or the heart of the lion.

Regulus is a young, fast spinning star, making a complete revolution about every 16 hours, a spin so quick it makes the star bulge in the middle. And, while Regulus is a very bright first-magnitude star, it is actually 77.5 light years away.

By Wednesday morning, the Moon will have moved on again, its crescent growing smaller still as it leaves Leo and passes just to the right of the brightest star in Leo’s tail, Denebola, a name which means “tail of the lion” in the original Arabic.

While second-magnitude Denebola is not nearly as bright as Regulus, it is actually larger at 1.6 million miles wide compared to Regulus’ 1.4 million mile girth. It’s also closer, less than half as far away at 36 light years.

If Denebola is closer and bigger than Regulus, why does Regulus shine more brightly? Simply because it is hotter, its higher temperature making it shine 350 times brighter than our Sun. Cooler Denebola is a mere 12 times brighter than 865,000-mile-wide Sol.

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Join the Tulare Astronomical Association for a look at the stars of autumn Friday, 7:30 to 9:30 p.m., at the Arthur L. Purcell Observatory, 9242 Ave. 182, south of Tulare and 2.1 miles west of Highway 99. Information and directions: http://starry-starry-nights.blogspot.com/.

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This column originally appeared in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on Oct. 12, 2006.

Don’t Mourn for Pluto

2006-10-25T17:31:00.000-07:00

Don’t Mourn for Pluto
by Dave Adalian

After 76 years as the Solar System’s ninth planet, Pluto suddenly finds himself all alone out in the cold.

Of course, he’s probably used to that by now.

At a meeting of the International Astronomical Union last month, Pluto was stripped of its status and reclassified as a “dwarf.”

The poor little guy. But, does he deserve it?

Truth be told, Pluto is a whole lot different than his Sun-hugging cousins.

First off, he’s tiny, about half the diameter of Mercury, smallest of the rocky inner planets, smaller than many of the other planets’ moons, including Earth’s. His size really isn’t all that odd, except Pluto lives in the land of the gas giants, the smallest of which, Neptune, could hold 60 Earths if it were hollow.

Making Pluto even odder, his axis is inclined so much his north pole points at the Sun. But, he’s not alone here. Uranus, too is tilted on its side.

Also, the largest of Pluto’s three moons, Charon, is almost half as big as he is, making them a double system in the minds of some astronomers. And again, he’s not alone in this. Earth and the Moon are somewhat similar in size and considered a double planet in some circles.

So, what’s the fuss?

Well, the IAU’s new definition of a planet says planets have orbit the Sun, have to be round, can’t orbit another planet and have to clear their orbit of other objects. It’s that last item that’s gotten Pluto in hot water.

Pluto takes a unique path around the Sun. Not only is his orbit tilted, taking it up and down like a horse on a merry-go-round, that orbit is also highly eccentric, sometimes taking the small body inside the orbit of Neptune.

Pluto doesn’t move like the other planets do because it is one of the largest objects in the Kuiper Belt, and since there are thousands of other Kuiper Belt objects sharing Pluto’s orbit, he just doesn’t fit the IAU’s new definition. So, out he goes.

In general, astronomers aren’t an excitable bunch, but the decision last month has professional stargazers around the world crying foul. The vote, held on the last day of the IAU’s meeting, only included the opinion of a handful of the body’s 10,000 or so members, many of whom are calling for another vote on the matter.

So, Pluto might regain his status as a planet the next time the IAU comes together. Either way, Pluto probably doesn’t much care what people on a planet so far away it can’t even be seen from where he sits call him.

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This column originally appeared in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on Sept. 14, 2006.

Planets Dance in the Predawn Light

2006-10-25T17:10:00.000-07:00

Planets Dance in the Predawn Light
by Dave Adalian

Early risers and those who like to stay up until dawn will be treated to a planetary dance if they’ll look to the east before first light all next week.

On Sunday morning just before the Sun rises three planets will hover just above the eastern horizon. Brightest and easiest to find of the trio will be Earth’s twin sister Venus.

This 8,000-mile-wide orb is about the same size as our own planet, but covered with a planet-wide haze that reflects back much of the light that strikes it, making it one of the most dazzling sights in the night sky.

Closer to the horizon and to the left of Venus will be a close pairing of Mercury and Saturn. On Sunday morning, Mercury will sit about a degree above the ringed planet and both will be very close to the horizon. Twenty-four hours later, the pair will have switched positions, with swift-footed 3,000-mile-wide Mercury moving so quickly toward the Sun it will appear about one degree below slower-moving Saturn.

Also joining the dance on Monday morning will be a very slender crescent moon sitting above the planetary trio. The Moon will be even thinner still, as thin as you are ever likely to see it on the last day of its 28-day cycle, on Tuesday morning when it floats near Saturn’s left-hand side.
For a striking example of what a difference distance makes for planetary viewing, remember that our moon is just 850 miles more narrow than faraway Mercury but appears roughly 166 times larger to the naked eye.

By Wednesday morning, Venus and 75,000-mile-wide Saturn will be all alone in the eastern sky with Mercury lost in the wash of predawn brightening.

Their other dance partners now gone, Venus and Saturn will go it alone over the next several mornings while Venus makes its way closer to Saturn and sunup each day.

On Tuesday, with the Moon close at hand, Saturn and Venus were some 5 degrees apart, by Friday the gap will have narrowed to less than 2 degrees, or about four times the width of the full moon.

The gap will be at its smallest over the weekend when Venus will be less than one degree above Saturn, and the final move of the celestial cotillion will come on Sunday morning when the two change position, with Saturn now less than a degree above Venus.

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Join the Tulare Astronomical Association for its monthly public star party this Friday, 9-11 p.m., at the Arthur L. Purcell Observatory, 9242 Ave. 184, south of Tulare and 2.1 miles west of Highway 99. Information and direction: http://starry-starry-nights.blogspot.com/.

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This column originally appeared in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on Aug. 17, 2006.

A Sky Without Stars

2006-06-24T12:51:00.000-07:00

A Sky Without Stars
by Dave Adalian

The greatest bane of astronomers is encroaching light.

When the Moon is full or the neighbor leaves his porch light on all night the splendor of the starry sky is ruined.

Fortunately, in Tulare County (Calif.) we can always retreat to the countryside and the vast open acres of croplands and grasslands.

My favorite place to remove myself from the lights of an increasingly bright Central (San Joaquin) Valley is the lonely cattle country of Yokohl Valley east of Rocky Hill.

Out among rolling hills covered in brown grass baked in the heat the sky is still a jewel encrusted dome, where thousands of lights dazzle on a velvet backdrop. Just minutes from downtown Visalia (Calif.), where the star clouds of the Milky Way are never seen, our home galaxy stretches itself from horizon to horizon so beautifully it pulls the breath from your body.

Just five miles down a winding two-lane road there is isolation almost complete, where seeing more than two cars in a night is heavy traffic. Owls cry in the dark. Coyotes yip and laugh and howl to one another among the silhouettes of ancient oak trees standing sentinel on far away ridge tops. It is so quiet you can hear the clicking screech of bats finding their way through blinding inkiness.

Yokohl Valley is a place that I hold dear, and it has been my secret retreat for a dozen years. Now, I’m sharing it with you.

You’d better get there soon.

I’ve been selfish with my hideaway, but no more. As many people as can come should see the wonder of this hidden foothill valley before it’s gone.

An international corporation has decided to turn my secret Eden into a retirement community. If our leaders lend support to this idea, the splendor of Yokohl Valley will soon be no more.

The land will still be there. The stars will still shine overhead, too, but we’ll never see them in the glow of a thousand shining street lights.

Come out to Yokohl Valley before the Sun sets and let the blazing summer turn into cool, dark night around you. Let the sweet smell of wild grasses baked in the sun fill your senses. Hear nighthawks’ screams echo among the rocks and feel the chill on your skin as the coyotes call to one another across the empty spaces.

See the stars shining over this doomed valley before they’re lost forever.

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Join the Tulare Astronomical Association for a public star party this Friday, 9:30-11:30 p.m., at the Purcell Observatory, 9242 Ave 198, south of Tulare (Calif.) and 2.1 miles west of Hwy 99. Information: http://starry-starry-nights.blogspot.com/.

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This column originally appeared in the Visalia (Calif.) Times-Delta and Tulare (Calif.) Advance-Register on Thurs., July 13, 2006.

Solstice Marks Summer's Start

2006-06-13T20:38:00.000-07:00

Solstice Marks Summer's Start

by Dave Adalian

Soaring temperatures may make it seem like summer has already arrived, but even so the astronomical start of the season is still nearly a week away.

Summer, according to astronomers, begins with the solstice, the moment when the Sun reaches the northernmost point above the celestial equator, an imaginary line above Earth’s equator that divides the sky into northern and southern hemispheres.

The solstice is also marked by the rising and setting of the Sun as far north on the horizon as it can reach. If you watched the sunrise each day, you’d notice the Sun swings back and forth slowly along the horizon until it reaches its northernmost point in June and its southernmost point in December. Solstices mark the days when the Sun stops then reverses direction. In Latin the word solstice literally means Sun (Sol) stands still (sistere).

The Sun will reach the summer solstice on Wednesday at 5:26 a.m., just a few minutes before it rises, and summer 2006 will be underway.

Even if you didn’t have the Sun to set your calendar by, the stars could serve in its stead.

It’s a sure sign spring is at an end when the constellation Leo is standing on its head above the western horizon just after the Sun goes down. Find it by looking for the backward question marking the lion’s head and the triangle of stars that is its haunch.

Looking north, the Big Dipper of Ursa Major is propped up with its handle high in the air. Following the curve of its tail and extending it past the end of the handle and across the zenith takes us to bright orange Arcturus in the constellation Bootes. This star is the brightest in the summer sky and the northern hemisphere.

After arcing to Arcturus, continue along the curve from the Dipper and speed on to Spica, the brightest star in the Virgo. Don’t make the mistake of confusing Spica with bright Jupiter which sits just up and to Spica’s left.

The eastern sky holds a trio of bright stars so tied to summertime the shape they draw is named after the season. Deneb in the north, Altair in the south and Vega above them form the Summer Triangle. One of the brightest portions of the Milky Way spills through the center of the triangle and is visible even from urban backyards. For an even better view, head for the darker skies outside the city.

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This column originally appeared in the Visalia Times-Delta on Thurs., June 15, 2006.

The June Moon

2006-06-11T16:18:00.000-07:00

I've been playing the shutter bug this month with my new camera. My subject has been the Moon, and here are the results:

http://dave.adalian.googlepages.com/thejunefullmoon

Rain?!?

2006-05-19T16:38:00.000-07:00

Well, it's an official record. As I type this it is raining after an entire month of clear skies. This makes eight months in a row the Tulare Astronomical Society's monthly star party has been rained or fogged out. We'll try it again in June, folks...

You can check the hour-by-hour weather at the Arthur L. Purcell Observatory by clicking the link on the right side of this page.

Manmade ‘Stars’ in Summer Skies

2006-05-19T16:34:00.000-07:00

Manmade ‘Stars’ in Summer Skies

by Dave Adalian

If you’re gazing skyward on a warm night in late spring or summer and it appears one of the stars has come loose from its moorings to drift across the heavens there’s no need to worry. You’re not imagining things.

What you’re seeing isn’t a star. Instead it is something far closer to home, a satellite.
It used to be the only thing in orbit around the Earth was our moon, but with the first successful rocket launch into low Earth orbit by the former Soviet Union back in the middle 1950s everything changed.

Since then, mankind has peppered the heavens with more than 27,000 artificial satellites, from the huge International Space Station down to bolts, lost tools and bits of discarded trash, even an unlucky astronaut’s glove, all left to drift in space until Mother Earth’s relentless gravity finally coaxes them back for a fiery reentry into the atmosphere.

Of those various bits of stuff we’ve heaved into the sky, some 9,000 of them are still up there, and of those several hundred of are visible to the naked eye.

When you find one of these star-like pinpricks making its stately way through the heavens, what you’re seeing is actually reflected sunlight shining off it. How bright a satellite appears depends on several factors, including how high above the Earth it orbits, its size and how well it reflects sunlight.

During the shorter nights of the warmer months, the tilt of the Earth’s northern hemisphere toward the Sun not only causes summer’s weather, it also causes Earth to cast a shorter shadow. This means more of the satellites soaring overhead are exposed, which makes this the best time of the year to see them.

It also helps that the warmer weather makes it more likely would-be satellite hunters will venture outside.

Among the brightest of satellites is a group known as the Iridium Constellation. Dozens of these communications satellites surround the Earth, producing extremely bright flares on a regular basis.

Another favorite bright target of satellite seekers is the Hubble Space Telescope, which will be making a series of predawn passes throughout May before becoming an evening object again in June.

You can find out when the Iridium satellites, the HST and the ISS will be visible overhead where you live by visiting www.Heavens-Above.com.

The site also provides predicted appearances for dozens of other satellites, along with maps and observing tips.

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The column appeared originally in the Visalia Times-Delta on May 18, 2006.

The Stars of Winter Fade

2006-04-17T23:19:00.000-07:00

The Stars of Winter Fade
by Dave Adalian

With the spring rains finally starting to taper off it’s a good time to get reacquainted with the night.

As April comes to a close, the bright constellations of the winter sky drop quickly over the western horizon after darkness takes hold so you’ll need to catch them around 9 o’clock.

The most recognizable of the winter constellations, Orion, is lying low almost due west. At its most basic, Orion is a great rectangle of bright stars, including brilliant Rigel, at the western corner, and the red giant Betelgeuse sitting at the most easterly. In the center of Orion’s familiar shape are the three belt stars, Alnitak, Alnilam and Mintaka.

These three equally bright white suns form a straight line at Orion’s waist pointing the way to the sky’s brightest star, Sirius. Extend the line of the belt to the south and you’ll find Sirius shimmering in the southwest. Sirius, which sits in the constellation Canis Major or the Big Dog, is the brightest star as seen from Earth.

Following the belt stars of Orion in the other direction leads to the V-shaped face of Taurus the Bull. This gathering is actually an open cluster of associated stars known as the Hyades. Brightest among them is the red giant star Aldebaran, however, Aldebaran isn’t actually a member of the Hyades but only appears to be sitting in front of it from our vantage.

Aldebaran is sometimes called the Bull’s Eye, but its name translates as “the Follower.” It earned the moniker because it seems to trail the Seven Sisters of the Pleiades through the sky. You’ll find the Pleiades just north of the Hyades.

Above the Hyades and the Pleiades is a ring of five bright stars in the constellation Auriga the Charioteer. This group is an ancient one known as Rukubi the Chariot to the Babylonians.
The most northerly star in the ring is also its brightest, Capella the She-goat.

Southeast of Auriga, just above Orion, are the twin stars Castor and Pollux of Gemini.

All of these constellations are mainstays of winter, but spring is in full bloom now and a sure sign of this is Leo riding high overhead. To find the lion search for a reversed question mark that outlines Leo’s mane. Nearby is a triangle of stars that is Leo’s hindquarters. The brightest of these is Denebola, the “tail of the lion.”

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This column originally appeared in the Visalia Times-Delta on Thursday, April 20, 2006.

Stargazing Without Stars

2006-03-20T18:43:00.000-08:00

Stargazing Without Stars
by Dave Adalian

The rain we’ve been getting for the last two months is great if you’re a farmer or a frog. But if you’re an amateur astronomer eager to see the night sky the constantly cloudy skies are enough to make you want to do an anti-rain dance.

Time spent waiting for the rain gods to grow tired doesn’t, however, have to be time spent away from the stars if you’ve got an internet connection.

Amateur astronomy is a hobby for those of us who think all things scientific are pretty nifty, in other words geeks, and the internet falls squarely in our zone of interest. That means there are tons of astronomical websites available to keep the soggy stargazer busy on cloudy nights.

If you’re looking for the latest news of the night sky, you can point your browser to any one of dozens of news services. Among the more popular are the home of Astronomy Magazine, astronomy.com, and the home of Sky and Telescope Magazine, skyandtelescope.com.

Services like SpaceRef.com and Space.com will put the latest in space exploration and astronomy news in your email in-box on a daily basis when you sign up at their homepages.

For discussing the latest news about the heavens with fellow astronomers there are some great online forums. CloudyNights.com is a popular message board, and a host of similar discussion groups are available at http://groups.yahoo.com. Some of the more popular groups there include Astronomer, Starry Nights and WannaBeAstronomers, a group for those just dipping their toes into the Milky Way.

Also at Yahoo! Groups is CenCalAstro, a group of Tulare, Kings, Kern and Fresno county amateur astronomers who post news of local sky watching events.

If you’re looking for help planning a stargaze once the weather clears, head to SkyMaps.com, where you’ll find printable maps of the night sky for the current month, along with lists of recommended targets for the naked eye, binoculars and telescopes, as well as tips for making the most of a night’s viewing.

You can also find out what artificial lights will be up in the night sky at Heavens-Above.com, a site that alerts readers about what satellites--including the International Space Station, the space shuttle when it’s aloft and the Hubble Space Telescope--will be visible and when.

Finally, if you just like to look at pretty pictures, then the Astronomy Picture of the Day is the place for you. Check it out at antwrp.gsfc.nasa.gov/apod/astropix.html.

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This column originally appeared in the Visalia Times-Delta on Thursday, March 23, 2006.

The Underside of Clouds

2006-02-17T08:57:00.000-08:00

Unless we get a radical clearing of the sky before this evening, which the weatherman says isn't going to happen, we'll being giving the Feb. 17 star party a miss. Sorry, folks! I was looking forward to it, too, but I'm not driving all the way to the observatory just to look at the underside of clouds...

Since you already set aside the time, why not head over to the College of the Sequoia's for tonight's SVPC Presents the Talk of the Town: Global Warming and the Central Valley? The presentation is at 7 p.m. in Lecture Hall 350 (behind the COS Theater), 915 S. Mooney Blvd. in Visalia. The speaker will be Erin Rogers of the Union of Concerned Scientists.

Earth’s Bright and Angry Sister

2006-02-15T20:09:00.000-08:00

Earth’s Bright and Angry Sister
by Dave Adalian

That bright light shining in the east during early morning hours this spring isn’t a UFO, and it’s not an airplane coming in to land, either.

It’s Earth’s sister planet, Venus.

Of the four inner rocky planets of our Solar System, Venus is the most like our home--but there’s a world of difference, too.

Venus is almost exactly the same size as Earth, just over 400 miles slimmer at the equator, and boasts 80 percent of our planet’s mass. Venus and Earth (and Mercury and Mars, too) are also made of pretty much the same stuff, unlike the outer gaseous planets, and at one time Venus had its own water.

This is where the similarity stops.

Venus is about one third closer to the Sun on average than Earth, and solar heating caused by this proximity kept the water on Venus from becoming a liquid. Having an atmosphere comprised of mostly water vapor led to an extreme greenhouse effect, with the trapped heat eventually destroying Venus’s water and driving huge amounts carbon dioxide from the surface rock, pushing the heat even hotter.

Today, temperatures on Venus range from lows in the 260-degree range with highs approaching 900, and the atmospheric pressure is 90 times that of Earth at sea level. These conditions are widely, famously and rightly reported as being hot and nasty enough to melt lead.

Adding to Venus’s oddness is its retrograde rotation. While the other planets turn counterclockwise as seen from above their north poles, Venus rotates clockwise, meaning on Venus the Sun rises in the west. But, you’d have to wait a long while to see it.

Venus, because it is closer to the Sun, has a year that is only 225 Earth days long, but it takes 243 days to turn on its axis. On Venus, a day is longer than a year.

As 2005 ended, Venus put on a months-long display as the spectacular Evening Star, dazzling in the west during the hours after sunset.

Now, she’s back, only this time in her incarnation as the Morning Star, shining her brightest for 2006 tomorrow during the hours before dawn when early risers will find her hanging jewel-like in the predawn eastern sky.

This apparition will last into May, when we should be hearing much more about Venus and its bright atmosphere as the European Space Agency’s Venus Express probe reaches our sister planet and begins returning data on the makeup of its stifling conditions.

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This column appeared originally on Feb. 16, 2006 in the Visalia Times-Delta.

The Other King of the Planets

2006-01-18T12:54:00.000-08:00

The Other King of the Planets
by Dave Adalian

While Jupiter is regarded as king of the Roman gods and of the planets, he’s actually got a rival in the night sky, Saturn. But, it’s all in the family.

Saturn’s counterpart in Greek mythology, Cronus, was king of the Titans, who were the beings that ruled the Cosmos before the birth of the gods. It was foretold that one of Cronus’ children would replace him as ruler of all that is, but Cronus had a plan to stay in power. He decided to eat his offspring as they were born to his wife Rhea.

Problem solved.

But it wasn’t. When Rhea gave birth to Zeus, the Greek equivalent of Jupiter, instead of giving Zeus to Cronus she gave him a rock, which Cronus swallowed instead. After Zeus was raised by a magic goat, he forced his father to cough up the other gods and took his father’s throne.

Cronus, or Saturn as we know him, is actually larger than his son Jupiter, at least if you count his rings. While Jupiter is some 88,000 miles wide, Saturn’s ring system spans twice that distance at 176,000 miles. Saturn’s disk is 75,000 miles wide.

Saturn, which is the sixth planet out from the Sun, will be at its closest and brightest for the year on the night of Friday, Jan. 27.

Right now, Saturn is in the constellation Cancer, rising just as the Sun is setting. By midnight it reaches its highest point in the sky, shining bright and yellow. Even though Saturn appears so bright, it will still be 755 million miles away when it makes its closest approach to Earth next week.

Besides being the only planet in our system with a set of rings visible from Earth, Saturn is also less dense than regular water. That means if there was an ocean big enough to dunk it in Saturn would float.

Out of the more than 140 moons in the Solar System, Saturn’s moon Titan, at 3,200 miles wide, is the second largest, just 80 miles more narrow than the largest, Jupiter’s Ganymede.

Titan and several of Saturn’s other moons and the beautiful rings are visible from Earth through a telescope, but the planet is still a wonder even without one. This will be especially true during the first few days of February when the ringed planet slides into a bright star cluster in Cancer known as the Manger.

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This column appeared originally in the Visalia Times-Delta on Jan. 19, 2006.

Long Nights full of Planets

2005-12-22T15:07:00.000-08:00

Long Nights full of Planets
by Dave Adalian

For the price of a little midnight oil, along with some luck and a bit of persistence, the naked-eye planets can all be viewed in a single night this week. But, you’ll have to move quickly and be eagle-eyed.

The easiest of the nighttime wanderers to find is Earth’s sister planet, bright Venus, which, like Earth, is about 8,000 miles wide. Even though Venus now appears as the wisp of crescent through a telescope it shines brilliantly as the Evening Star low in the southwest before it chases the Sun over the horizon.

Far more difficult to find is 30,000-mile-wide Uranus, the dimmest of the naked-eye planets. It too is in the southwest just after sunset, in the constellation Aquarius, but unless you know exactly where to look you’ll likely miss it. You’ll also need a very dark viewing spot well away from city lights.

While Uranus, the father of the Titans, can be seen without optical aid, your best bet is to look for him with binoculars on the night of Tuesday, Jan. 3, when he’ll be just a degree or so northwest of the new moon. His methane-rich atmosphere will make him look like a bluish star.

Far easier to find is bright and ruddy, 4,000-mile-wide Mars. The God of War sits high in the sky just after sundown, almost straight overhead. He’ll make his way slowly across the sky as the night moves on, finally setting in the early morning hours.

Mars will remain a prominent feature of the night for many month yet, not passing from the sky until spring turns to summer.

Just now making his move into the evening sky is golden Saturn, the 74,000-mile-wide ringed planet. He rises about 8 p.m. in the constellation Cancer and takes the entire night to cross the sky, setting in the hour after dawn.

West of Saturn is a ghostly naked-eye star cluster known as the Beehive.

Rising at about 3 a.m. is 88,000-mile-wide Jupiter, King of the Gods. This bright gas giant planet with its bands of red and swirling storms is directly southwest as dawn begins.

Minutes before the Sun rises the last of the naked-eye planets appears. Swift 3,000-mile-wide Mercury hovers just above the horizon as the sky begins to brighten, heralding the return of daylight. By the end of the week fleet-footed Mercury will be impossible to find as it fades back into the glare of the Sun.

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This column appeared originally in the Visalia (Calif.) Times-Delta on Dec. 22, 2005.

A Story in the Stars

2005-11-24T00:00:00.000-08:00

A Story in the Stars
by Dave Adalian

High in the northern sky this time of year hangs the bright constellation Cassiopeia, the Seated Queen, and with her a tale of love, vanity, monsters and heroism that is as old as western civilization.

Vain Cassiopeia ruled ancient Aethiopia with her husband, King Cepheus. She was indeed lovely and bragged she was even more beautiful than the Nereids, companions of the sea god Poseidon. As punishment, Poseidon sent a terrible monster, Cetus, to wreak his vengeance upon the land.

King Cepheus consulted the oracle for a divine solution and was told he must sacrifice his daughter Andromeda to Poseidon to end the terror. So, at the king’s orders Andromeda was chained to the rocks at the edge of sea to die.

But death did not come to the maiden.

The hero Perseus was returning home after slaying Medusa, whose snake-haired head could turn men to stone. Flying through the sky on the winged sandals of Hermes, god of the underworld, Perseus spied Andromeda below and instantly fell in love. He swooped to her rescue and slew Cetus, saving both the girl and her land.

With Aethiopia secure, all was well, except for Cassiopeia. As punishment for her vanity and the trouble it caused she was doomed by the gods to ride forever in circles about the North Star, spending half the year dangling in embarrassment from her throne.

Cassiopeia’s bright stars form an obvious W-shape during warmer months. But on the longer nights of fall and winter the queen sits upside down, tied in her chair to keep from falling, and the W becomes an M above the North Star at about 8 p.m.

Cepheus’ faint constellation lies between the North Star and Cassiopeia, and Cetus, another dim group, is opposite Cepheus in the sky, far south with only a single bright star, Diphda.

Andromeda’s constellation and the bright and misty naked-eye galaxy that bears her name sit directly overhead around 8 o’clock during autumn nights. Perhaps her galaxy reminded the ancients of spindrift blown up from the waves that crashed around her feet as she awaited her terrible fate.

Perseus, holding Medusa’s head, is a starry constellation east of Cassiopeia. Medusa was also mother of Pegasus the winged horse, and his constellation and its Great Square shine west of Andromeda. West of Pegasus is the tiny Equuleus the Horse, which some say shows Chrysaor, earthbound brother of the flying horse.

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This column appeared originally in the Visalia (Calif.) Times-Delta on Nov. 24, 2005.

Real Deal on Mars

2005-10-12T13:50:00.000-07:00

Real Deal on Mars
by Dave Adalian

If you were hoping to see Mars appear the size of a full moon last August, as a widely circulated hoax email suggested it would, no doubt you were very much disappointed.

Some prankster decided for reasons known only to himself to twist information about the close pass of Mars back in 2003 to make it sound as though the Red Planet would make an impossibly close pass by Earth this summer.

Thankfully, it didn’t happen. Had Mars come close as that hoax email described, the resulting disruption to Earth would have spelled disaster.

The real facts are these: Back in August 2003, Mars came closer to Earth than it has during recorded human history, about 34.6 million miles. For those lucky enough to get a look at the God of War through a telescope at 100X magnification during that close approach, its disk appeared the same relative size as a full moon does when viewed with the naked eye.

As I said in this space during summer of 2003, in a scope Mars looked like a pea in a Petri dish, although a beautiful one with reddish planes, dark surface features and clouds obscuring the southern pole -- in other words, like an alien planet that we still cannot be sure doesn’t harbor life of some kind.

If you missed it during summer 2003, it won’t be as close again until 2287. It really was a once-in-a-lifetime experience and a spectacular one at that.

But life is as full of second chances as it is once-in-a-lifetime opportunities.

Mars is coming in for another close pass this month, one of 40.3 million miles, a mere 4.3 million miles further away than in 2003. Bumping up the magnification to about 125X will give that full-moon effect once more. And, yes, it will be a breathtaking sight to behold.

Opposition, when Mars rises at sunset, will happen on Nov. 7, but the closest pass will come two nights before Halloween, when a pumpkin-colored Mars will rise about 6:30 to fly high in the east and come closest at about 8:25 p.m. It will be shining high and bright still when trick-o’-treaters take to the streets on Halloween.

Tonight, Mars is in the east over the trees by about 9 o’clock. If you watch night by night, you’ll see it rise earlier and double in brightness by October’s end as autumn’s warmth fails.

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Join the Tulare Astronomical Association Friday, Oct. 21, 8-10 p.m., for a close-up look at the Angry Red Planet at the Arthur L. Purcell Observatory, 9242 Ave. 184, 2.1 miles west of Highway 99. Information and directions: http://starry-starry-nights.blogspot.com/.

Clouds Win Again

2005-09-23T18:39:00.000-07:00

Sorry, folks, but the satellite images show that this cloud cover over Central California is probably going to last most of the night, so there goes the star party. We'll try again on Friday, Oct. 21. See you then!

Return of the Long Nights

2005-09-19T13:25:00.000-07:00

Return of the Long Nights
by Dave Adalian

Summer is taking an early departure this year, folding away her brown mantle and allowing the cool days and chill nights of autumn to come quickly as the leaves begin to fall.

This is fitting as (on Sept. 22, 2005) at 2:23 p.m. PDT the Sun crosses south of the celestial equator, reaching equinox and marking the moment when autumn begins and the days shorten while nights grow long and cold.

When the Sun sets this evening, it will fall directly west and rise again tomorrow due east, silhouetting the crags of the Sierra Nevada. Though the periods of light and dark won’t be perfectly equal as the Latin term equinox implies, the time between sunset tonight when half the Sun’s disk is below the horizon and sunrise tomorrow when half the disk is above the horizon will be just eight minutes shy of 12 hours.

The equinox is the moment when the Sun crosses the dividing line that splits the sky into two equal northern and southern halves, creating some special effects here on Earth.

At the equator on the days of the March and September equinoxes, the Sun not only rises and sets at the points of true east and west, it also passes directly overhead when it reaches its highest point in the sky, something it never does at more northern or southern latitudes.

At the poles, the effect is far more dramatic.

At the North Pole, the September equinox signals a plunge into six months of darkness, with the Sun dropping below the horizon not to be seen again until the end of March.

On the bottom of the planet, the effect is reversed, with the Sun finally returning to the sky for six uninterrupted months of daylight. Instead of rising and falling as it does elsewhere, during the months-long period of day the Sun skims along the icy horizon, climbing higher in the sky as the solstice approaches.

Were it not for the killing cold of the arctic winter, the North Pole would be a Moon-lover’s delight. During the six-month darkness, the Moon rises above the horizon not to set again for two weeks. The Moon moves through its cycle in unashamed plain sight before dipping again below the horizon for a fortnight’s absence.

Late Sept. 21 and 22 here at home, the Moon will put on a beautiful display in the east, joining the Seven Sisters of the Pleiades, the V-shape of the Hyades and a bright and ruddy Mars.

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Join the Tulare Astronomical Association for a public star party this Friday, Sept. 23, 8:30-10:30 p.m. at the Arthur L. Purcell Observatory, 9242 Ave. 184, south of Tulare and 2.1 miles west of Highway 198.

Deep Impact Reveals Comet's Secrets

2005-09-09T23:47:00.000-07:00

The first findings from the Deep Impact collision with Comet Tempel 1 back in early July have been announced and the mission's results are going to change the way astronomers think about comets in a lot of ways. We've assumed comets were dirty snowballs, but it's looking more like they're icy dirt balls made mostly of powder and have the consistency of a soufflé, so don't slam the oven door or your comet may collapse.

Here's a great article on the findings from Science News.

Soak In Some Earthshine

2005-09-06T10:09:00.000-07:00

When a very slim crescent moon joins Jupiter, Venus and Spica on the western horizon tonight just after sunset, be sure to look for the Earthshine, too.

The Sun is the only source of bright light in our solar system. All the light coming from the planets and their moons is just a reflection of our home star. When the Moon is only a couple of days past its new phase it presents a large dark limb, and the light that makes that dark limb visible is Earthshine, light from the Sun that strikes the Earth, reflects back to the dark portion of the Moon and then shines back on the Earth.

Venus and the Virgin

2005-09-05T13:34:00.000-07:00

The sky show continues tonight on the western horizon after sunset with Spica, the alpha star of Virgo the Virgin, shining less than two degrees southwest (down and to the left) of Venus. Jupiter is about four degrees to the right. For those with a clear view to the west, a very young new moon is just above the horizon and will set by about a quarter after 8 o'clock local time. The Moon will be right in the midst of this grouping tomorrow night 30-45 minutes after the Sun goes down.

One Hundred Billion Failed Stars

2005-09-04T00:52:00.000-07:00

For every star shining in our galaxy there's another one that didn't make it. Astronomers at Arizona State University working from Hubble Space Telescope infrared data have discovered the Milky Way has as many brown dwarf bodies as it does stars -- 100,000,000,000 of them and every one without enough mass to begin nuclear fusion, the process that makes the stars shine. These dark bodies weigh anywhere between 13 to 75 times as much as Jupiter, so their combined mass isn't enough to account for all of the galaxy's so-called missing matter by a long shot.

Here's Astronomy.com's article announcing the discovery.

Look to the West

2005-08-29T19:16:00.000-07:00

Don't forget the meeting of Jupiter and Venus. Look due west 30 minutes after sundown to see these bright planets converge. They'll come closest to one another Thursday, Sept. 1, when they'll be about 1.2 degrees apart, just more than twice the width of a full moon or about the width of your pinkie finger when held at arm's length.

Click here for my earlier, more detailed post about this conjunction.

CalStar Party at Lake San Antonio

2005-08-27T16:19:00.000-07:00

Lake San Antonio is a great dark-sky location and CalStar is a well-attended party attracting observers from all over the state. The 2005 CalStar, hosted by the San Jose Astronomical Association, will be held Sept. 29-Oct. 1 at Lake San Antonio, 25 miles east of Paso Robles.

Details are here:

http://www.sjaa.net/calstar2005.html

Mars NOT Looming Large

2005-08-24T18:59:00.000-07:00

If you expect to see Mars swelled to the size of a full moon on Saturday, Aug. 27, 2005, you've probably been the victim of a cruel hoax. Someone, for reasons known only to himself, decided to pull a prank on all the would-be planet-gazers out there by sending around an email describing a closer-than-ever pass of Earth by the Red Planet.

It's not going to happen, at least not again.

Most of the information in this fatuous email is very near the truth about the close approach of Mars back in summer 2003. Mars did come closer to Earth than it has in 60,000 years and it did appear the size of a full moon, but only if you viewed it magnified by 100 times in a quality telescope. I wrote a column about it at the time, which you can read here.

The good news for those who'd like a gander at the God of War is he'll be making a bright appearance at the end of October and beginning of November. Watch this space as details will come as the date approaches. In the meantime, Mars is coming up in the east about 11 p.m. your local time, and over the month of September it will double its brightness, which is a great reason to start watching now.

Hubble Scanning Moon for Base Sites

2005-08-22T09:41:00.000-07:00

I know this is meant to be an astronomy blog, but I find this so cool I have to post it. The Hubble Space Telescope is being used to look for lunar base locations. I'll be packing my bags! Here's the story as told in New Scientist magazine.

Wanna See Something Beautiful?

2005-08-20T10:43:00.000-07:00

Go out and look west tonight just after sunset and you'll see two extremely bright "stars" down near the horizon. These are really Jupiter, king of the gods, and his daughter Venus, goddess of love. Venus is the one on the lower right and Jupiter is up to the left.

Over the next two weeks they are going grow closer until they reach their closest on the nights of Wednesday, Aug. 31 and Thursday, Sept. 1. Keep watching as they part ways because on Tuesday, Sept. 6, they're going to be joined by a very slender sliver of a moon. Make sure to look for earthshine in the Moon's darkened limb that night.

Venus and Jupiter will be easiest to find about 30-45 minutes after sunset. If you have trouble finding planets, here's a Quicktime video of this conjunction from skyandtelescope.com that may help.

Full Green Corn Moon

2005-08-19T00:35:00.000-07:00

The Moon is full today, Friday, Aug. 19. Because this is the month before harvest begins in many areas, this full moon is sometimes known as the Green Corn Moon or the Grain Moon. It's also the Full Sturgeon Moon, this being the season when that fish is most easily caught. (But don't ask me why--damn it, Jim, I'm an astronomer not a ichthyologist!) You'll find the names of each month's full moon here:

http://www.space.com/spacewatch/full_moon_names_2005.html

The Strolling Astronomer

2005-08-14T23:14:00.000-07:00

The Strolling Astronomer
by Dave Adalian

During summer I take my walks after the Sun is down, when my family's gone to bed and the heat of the day has faded. I stroll among the stars, hoping for the thrill of a meteor and making sure those points of light are still fixed to their places.

My front door faces east, and as August fades the Great Square of Pegasus, part of the winged horse’s constellation, hovers above my neighbor’s rooftop. Later the Square will rise high into the night sky, trailing Pisces the Fish behind, but early on it sits on its eastern point, a huge diamond-shape of stars.

Right of Pegasus’ Square are the dim, indistinct zodiacal constellations of Aquarius the Water Bearer and Capricornus the Sea Goat. This seemingly empty ocean of sky has a single bright star, lonely Fomalhaut in Pisces Austrinus, the southern fish, hanging over the southeast horizon, bobbing above the houses as I lope along.

Beyond this barren portion of the night is Sagittarius the Archer with his famous Teapot asterism and to his right the long, barbed hook of Scorpius the Scorpion, home of the red supergiant star Antares. Despite the city lights, I can still sometimes see the Milky Way rising like steam from the Teapot’s spout to trail beside huge Ophiuchus, the snake-handler, whose healing power defied death itself until Zeus immortalized him in the sky.

Walking west, I see the orange star Arcturus shimmering in the heavy air marking Boötes the Plowman, and above it is a half-circle of stars, Corona Borealis, the Northern Crown. Higher still is brave Hercules, club at the ready.

As I march along, I catch glimpses of the Big Dipper in Ursa Major among the trees and housetops northwest, and due north is always faithful Polaris, the North Star, in the Little Dipper in Ursa Minor. When I finally turn back toward home again there is the W-shape of Cassiopeia the Queen standing on edge in the northeast, and below her the hero Perseus defending Andromeda, the Chained Lady, who lends her brightest star to Pegasus as the northernmost corner of his Square.

I arrive back at my doorstep and crane my neck to look straight overhead for the Summer Triangle: Altair in Aquila the Eagle, white Vega in Lyra the Lyre and Deneb marking the tail of Cygnus the Swan. Then I quietly steal inside, careful not to awake those who lie sleeping.

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This column appeared originally in the Visalia (Calif.) Times-Delta on Aug. 25, 2005.

And Still More Perseids

2005-08-12T11:15:00.000-07:00

I woke up at a quarter past three and came back outside where I stayed until about a quarter after four, lying under a blanket on the diving board at the north end of the yard where the light is least. I spotted another 25 Perseids and three more meteors from other sources, including two that seemed to come from the direction of Aquarius, home to a minor shower or two this month. What a beautiful night of viewing, especially considering I was able to do it from my own backyard.

Perseids Watch

2005-08-12T01:54:00.000-07:00

I did a short Perseid meteor watch from my backyard tonight starting at about 12:40 and going until just before 2 a.m. I saw 22 Perseids, some of them very bright and beautiful, and about five sporadic meteors. I'm going to get some sleep now, but I may come back for another look in about 90 minutes.

Astronomy TV Online

2005-08-06T15:53:00.000-07:00

Here are a couple of astronomy-oriented television programs available via the web:

First, here's Jack Horkheimer's Star Gazer, a series of one- and five-minute programs on the week's astronomical highlights. And, second, the venerable The Sky at Night hosted by Sir Patrick Moore.

Getting to the Purcell Observatory

2005-08-05T00:00:00.000-07:00

Getting to the Arthur L. Purcell Observatory is very simple in broad daylight, but can be a bit tricky in the dark.

Take Highway 99 south past Tulare to the Avenue 184 exit. Turn left onto Avenue 184 and drive west approximately 2.1 miles. To do this you'll have to go through the intersection of 184 and Road 96; the observatory is about half a mile past the intersection on the right-hand (north) side of the road, so keep an eye on your odometer.

We have a sign for the observatory at end of the driveway, but it sits slightly off the road and is not lighted. The driveway leads to our parking lot, and the observing is done in our courtyard just beyond.

If you're not comfortable walking in darkness, a flashlight with a red filter will help, but please do not use unshielded lighting once you have left the parking lot.

This interactive Google map can provide driving directions from any location in Tulare County.

Welcome to Starry Nights!

2005-08-04T17:04:00.000-07:00

Welcome!

This is the new online home of my astronomy column, Starry Nights, published monthly in the Visalia (Calif.) Times-Delta. Besides posting my columns both old and new, I'll be including interesting astronomy-related news and links, as well as announcements of the Tulare Astronomical Association's monthly star parties.

Comet Dust Drives Summer Shower

2005-07-28T00:00:00.000-07:00

Comet Dust Drives Summer Shower
by Dave Adalian

(July 28, 2005) Anyone who attempted to observe Comet Tempel 1 earlier this month when NASA’s Deep Impact probe slammed it with an 814-pound copper bullet moving at 6.3 miles a second knows first-hand comets are an unpredictable lot.

Hopes were high this visitor from the outer reaches of the Solar System would brighten from an almost undetectable smudge in small telescopes to a naked-eye delight. The mission succeeded, but the brightening didn’t happen.

Fortunately, next month holds good promise of a sort for would-be comet observers.

August, as seasoned meteor observers know, is time for the year’s most reliable meteor sky show. The Perseids began lighting the night sky early this week and continue until late August with the peak expected to produce between 40-80 meteors an hour on the night of Aug. 11-12 and perhaps again on Aug. 12-13. Meteors from other minor showers will add 15-20 an hour.

Perseus, the constellation from which the Perseids stream, rises in the northeast around 10 o’clock. The best meteor viewing is after moonset--around 11 the first night and nearer midnight the next--until dawn. The darker sky you find yourself under, the better the viewing will be.

What does this have to do with comets? The Perseids are tiny pieces of Comet Swift-Tuttle.

Meteors aren’t really stars falling from the sky. Instead, they are bits that have broken off of other bodies--usually ice and dust the consistency of ash or more rarely solid rock--colliding with Earth’s atmosphere at several thousand miles an hour, ionizing the air and producing that magical glow.

Comet Swift-Tuttle is a periodic comet, returning again and again to swing around the Sun before heading off to the dark and frozen outskirts of our star system on a 135-year circuit. While Swift-Tuttle was first discovered in 1862, the shower it produces is known throughout history. During the 11th century, astronomers in China recorded an intense display, and Perseids are sometimes called St. Lawrence’s Tears to honor his martyrdom in coincidence with the shower of 258.

Swift-Tuttle returned most recently in 1992, freshening its trail of debris significantly as the Sun’s gravity drew the comet in, warming its surface and causing it to shed potential meteors. Therein lies this comet’s uncertainty. This year Earth enters the 1992 debris stream for the first time, and the usual rates of 40-80 meteors an hour on nights near the shower’s peak could be far higher than normal.

Or maybe not... We’ll just have to see.

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This column originally appeared in the Visalia (Calif.) Times-Delta on July 28, 2005.

When Worlds Collide

2005-06-23T00:00:00.000-07:00

When Worlds Collide
by Dave Adalian

The cusp of June into July is going to be a planet-hunter’s delight this year.

Eighty-eight-thousand-mile-wide Jupiter continues to reign over the southern sky, shining high after sunset. Ruddy Mars, as it moves toward another close pass by Earth in mid-November, is coming up in the east for night owls at around 1:30 a.m., just as Jupiter is retiring on the opposite horizon.

The three outer planets--Uranus, Neptune and Pluto--are all available to those with telescopes during various times through the shortened dark hours of early summer. From an unpolluted sky, those who know exactly where to look, perhaps by using an online guide such as www.skymaps.com, can see blue-green Uranus with the naked eye.

The real show, however, is in the west just after the Sun reaches the horizon.

Those who followed the progress of Saturn this year as it hovered in the constellation Gemini know it is coming to the end of its 2005 appearance. As June closes, Saturn is only visible for a short time before it follows the Sun and slips below the western horizon.

Already Saturn is almost lost in the afterglow of twilight and hard to see until at least 30 minutes after the Sun is gone. Look tonight around 9 o’clock to see that Saturn has a bright companion, Venus, sitting very close by and outshining it.

In fact, brilliant Venus sits at the center of a trio of planets, with Saturn to her left and speedy Mercury on the right. Together the three span only three degrees, just six full-Moon widths.

Friday the trio is even tighter, sharing just two degrees of sky, and the group will be its tightest on Saturday when Saturn, Venus and Mercury are just one and a half degrees apart with the ringed planet below the two innermost planets of our star system.

While they sit close compare the pink of Mercury, blue-white Venus and yellow Saturn. Notice too how the trio sits undisturbed in the sky while around them stars shimmer in the gloaming.

Keen-eyed observers noticed Mercury rising to meet Venus while the planetary trio gathered. Mercury moves closer still the next two nights as Saturn retreats until on Monday the two are less than one tenth of a degree apart, so close they may appear to the eye as a single point of light. The merger is a once-in-a-lifetime event, not happening again until 2070.

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This column appeared originally in the Visalia (Calif.) Times-Delta on June 23, 2005.

Hopping through the Sky

2005-05-26T00:00:00.000-07:00

Hopping through the Sky
by Dave Adalian

Anyone who’s ever looked up at night has noticed a problem facing astronomers: there are a lot of stars up there, and it’s easy to get lost in space.

That’s one of the reasons we have constellations, to help us fix in our minds the location of the wonders of the night. Still, knowing where to find a constellation only gives us the general location of whole groups of stars, some of them very large. How does anyone find anything among all those points of light?

They hop to it.

Star-hopping is an age-old and easy technique. Start by finding a bright star or well known constellation and connect the dots to find the target.

The best known star-hop is the Arc to Arcturus. It starts with one of the better known constellations in the sky, Ursa Major, the Big Bear.

The most recognized star shape in the sky, the Big Dipper, lies in the Ursa Major. Find it by looking due north just after sundown. As spring wraps up, the Big Dipper pours its contents onto the North Star and its tail points up and toward the east.

Follow the arc along the three bright handle stars about the same distance as the length of the Dipper to come to the first stop, the orange giant star Arcturus.

Arcturus is the brightest star in cone-shaped Boötes (boo-OH-tes), the Herdsman, and the fourth brightest seen from Earth. It’s 20 times larger than the Sun and shines 115 times brighter from 37 light years away. Arcturus is so bright in the infrared we can measure its heat here on Earth--the same as a candle flame five miles away.

Arcturus is one of the fastest stars, traveling at 90 miles a second toward Virgo, the second stop on this star-hop. If you “speed” along the arc past Arcturus, you’ll soon come to first-magnitude Spica, Virgo’s brightest star. Like Arcturus, Spica is brighter than the Sun, 13,400 times so, and masses 11 times more, but it sits 260 light years away.

Continue the arc again to reach our final stop, Corvus the Crow, an irregular box of four stars that is normally not a big attraction. Currently, however, it’s pointing its beak towards Jupiter, which sits directly above the Crow.

Astronomers have an alliterative phrase to remember this popular hop: “Arc to Arcturus, speed on to Spica and continue on to Corvus.”

Enjoy the ride!

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This column appeared originally in the Visalia (Calif.) Times-Delta on May 26, 2005.

Moon to Hide Supergiant

2005-04-15T00:00:00.000-07:00

Moon to Hide Supergiant
by Dave Adalian

A fat full Moon is usually a problem for astronomers, its bright, white light washing fainter objects from the sky. Other times, it’s the star of the show, as it will be the night of May 23-24 when the Moon occults the red supergiant star Antares.

Occultation is a body blocking the view of another more distant body, and a few minutes before midnight on May 23 the Moon will do just that to the ruddy star at the heart of Scorpius. The show, however, starts at sunset.

In Arabic, Antares is called Kalb al Akrab, heart of the scorpion, and staying true to this metaphor, early Muslims named two bright nearby stars Al Niyat, the arteries. The brighter of the two artery stars, Al Niyat (Sigma), will be behind the Moon when it rises. Stargazers with access to a very clear horizon will see this third-magnitude star reemerge from behind the lunar disk at about 8:48.

About then Antares will become visible above the horizon, one and a half degrees or so below the Moon. As the Moon travels west across the sky, it moves east through against the starry background at about half a degree or one full-Moon width an hour, edging ever closer to Antares as midnight approaches.

The Moon appears much brighter and larger than Antares, but this is a mere deception of distance. The Moon is just a quarter million or so miles away and is roughly 2,000 miles wide at its equator. Antares, on the other hand, lies 600 light years away, is 12,000 times brighter than the Sun and measures 745 million miles across. Keep this in mind when the Moon makes supergiant Antares disappear from the sky at four minutes from midnight.

Another thing to keep in mind is Antares advanced age. While it is younger than Sol, our star, it is much larger and brighter, meaning a far shorter lifespan. When the end comes for Antares, it will be with a bang--because of its size, Antares will end life as a supernova.

That explosion could come at anytime, a million years from now or while the Moon is hiding it from view. Likely, Antares will emerge from behind the Moon at 1:12 a.m. no different than when it disappeared. Or, it may reappear as the aftermath of a titanic stellar explosion, outshining all the other stars in our galaxy combined.

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This column appeared originally in the Visalia (Calif.) Times-Delta in April 2005.

Return of the King

2005-04-01T00:00:00.000-08:00

Return of the King
by Dave Adalian

What’s bigger than a bread box, smaller than the Sun and the brightest thing in the night sky after the Moon these days? It’s 88,000-mile-wide Jupiter!

Those with eyes for the skies may have recognized the bright object dominating the east after sunset the last few weeks as the King of Planets. A fixture in the winter sky for the past few years, Jupiter is making the transition to spring skies as it moves to opposition--when it appears opposite the Sun and is up all night--on Sunday, April 3.

Not to insult the King, but Jupiter really is an old gas bag, and a big one to boot. Jupiter is the largest thing in the Solar System after the Sun, and while it’s only about six times wider than Earth, it would take more than the volume of 1,000 Earths to fill Jupiter’s interior.

Jupiter is so large that it contains more mass than all of the other planets combined, 1.9x10^27 kilograms worth--that’s a 19 followed by 26 zeroes! Astronomers who think they’re cleaver like to say the Solar System is made up of the Sun, Jupiter and assorted rubble.

The Jupiter System itself is fairly rocky, too. When Galileo first viewed Jupiter through a telescope in 1610 he saw just the four bright moons Io, Europa, Ganymede and Callisto. These days, Jupiter’s official NASA moon count is up to 63, with the smallest measuring just three miles across.

Moons aren’t the only thing going around Jupiter. Like Saturn, this gas giant planet also has a set of rings. Jupiter’s rings are much less complex and dimmer, so much so they weren’t discovered until Voyager I visited in 1979.

Like the Sun, the Jupiter is mostly hydrogen, and because of the gravitational pressure of its mass, inside temperatures reach more than 10,000 degrees Fahrenheit. That pressure has caused the formation of a core of metallic hydrogen 6,000 miles below the surface of Jupiter’s atmosphere. Some scientists believe the planet also has a rocky core 10 times the mass of Earth. Others disagree, saying it’s hydrogen all the way through.

In the telescope, dark, cloudy bands reveal themselves on Jupiter’s disk. The four bright Galilean moons are obvious as they dance along night to night, and careful observation reveals the Great Red Spot, a storm three times larger than Earth that has raged since before its discovery in 1664.

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This column appeared originally in the Visalia (Calif.) Times-Delta in April 2005.

Vernal Equinox on the Horizon

2005-03-03T00:00:00.000-08:00

Vernal Equinox on the Horizon
by Dave Adalian

Despite winter’s best efforts, spring is finally showing. Buds are turning to blossoms and temperatures are rising. The Sun is making the occasional appearance between rainstorms and soon it will let us know the season has changed.

Imagine the Sun, stars and planets as points of light on the inside of an enormous sphere surrounding Earth. Next, project a circle from Earth’s equator onto the sphere, forming a celestial equator dividing the sky into northern and southern halves. Then imagine another circle on the sphere, this one marking the Sun’s apparent path during the course of a year.

The two circles don’t match, and it’s that misalignment that causes Earth’s seasons. During winter months, the Sun sits south of the celestial equator so the northern hemisphere gets less light and temperatures drop. In the summer, the Sun appears to be north of that line and daylight hours are longer and hotter.

Twice a year, once in March and again six months later in September, the line marking the Sun’s progress and the celestial equator intersect. These events are known as equinoxes, Latin for equal night, and they mark the changes of summer to autumn and winter to spring.

This year’s vernal--or spring--equinox will happen at 4:34 a.m. PST on Sunday, March 20, when the Sun crosses the celestial equator and moves into the northern half of the sky. At that moment spring begins, and for a few days on either side of the event nighttime and daytime will be the same length.

Not coincidentally, the Sun rises exactly east on a few days surrounding the equinox and sets directly west. During the course of summer, the point on the horizon where the Sun rises and sets will appear to move north until summer solstice in June, when it again decsends toward fall.

The vernal equinox has been an important event for humans since the dawn of civilization. Ancient Egyptians paid homage to it by building the Sphinx to face sunrise that day, and closer to home the Mexican Pyramid of Kulkulkan, honoring the serpent god Quetzalcoatl, was designed so the shadow of the god appeared to slither down the steps on the equinox.

But, forget the egg balancing. Raw eggs do not balance on their ends more easily on the equinox. A Chinese New Year’s ritual performed about six weeks before the vernal equinox is the source of the myth.

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This column appeared originally in the Visalia (Calif.) Times-Delta on March 3, 2005.

Time to Look at Mars Again

2005-02-03T00:00:00.000-08:00

Time to Look at Mars Again
by Dave Adalian

Planet Mars grabbed big headlines in summer of 2003, making its closest approach to Earth in 60,000 years while millions turned out worldwide for the spectacular show.

Lately, the Red Planet has been sitting dim and far away on the other side of the Sun, but during the next 10 months that will change as Earth cozies up for another close pass. With nearly a year before Mars again becomes one of the brightest objects in the night sky, now is the time to start watching.

Think of Earth and Mars as cars on a race track. Mars sits farther out, moving slowly, while Earth roars along on an inside track. Even though Mars isn’t the speedster Earth is, it still takes us some 28 months to lap it, which is why we’re only starting to get good views of it again now as Earth rounds her home star.

Getting up early is required for finding Mars. The God of War is currently rising about 4 o’clock in the morning, but doesn’t clear the treetops until 30 minutes or so later. To sight it, look to the southeast near the horizon for its pink light.

Don’t confuse Mars with much brighter Antares, the brightest star in the constellation Scorpius that is also not far above the horizon in the southeast, but up and to the right of Mars. This red star is actually named for its resemblance to the Red Planet. Antares means rival of Aries, the Greek name for Mars.

Mars now sits just west of Sagittarius and will have moved to the east side of the Celestial Archer by month’s end. But, because it moves in the same direction around the Sun as Earth, there isn’t much change in the time it rises until the they’re far closer together. By April, Mars is up around 3 a.m., rising in Capricornus, and in May it’s up by 2 o’clock in Aquarius.

It spends the summer cruising through Pisces, picking up an hour each month and brightening along the way. Through September, Mars rises just after 9 p.m., almost due east, in Aries, where it will stay until it reaches its brightest and closest by mid-November. Then, it rises at sunset to shine overhead by midnight.

Mars won’t be as spectacular as summer 2003, but will certainly be well worth seeing, especially for those who weren’t watching the last go-round.

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This column appeared originally in the Visalia (Calif.) Times-Delta on Feb. 3, 2005.

Winter Stars Are Brighter

2005-01-06T00:00:00.000-08:00

Winter Stars Are Brighter
by Dave Adalian

Nights in winter seem starrier partially due to drier air overhead, but mostly because there are just more bright stars in the winter sky.

Winter begins with the Summer Triangle of Vega, Deneb and Altair lingering in the west after sundown. These jewels set quickly, and on the opposite side of the sky the Winter Hexagon’s easternmost members emerge.

By 7 o’clock, Sirius is high enough for viewing east of Orion’s belt. The Dog Star shines from 8.6 light years away in Canis Major, but because it is 20 times brighter than our sun remains the brightest star that can be seen from Earth at magnitude -1.4.

Sitting at due east and rising just before Sirius is a magnitude-0.0 star 11.4 light years distant. Because it rises just ahead of Sirius it’s known as Procyon, which means before the dog. A double star, its companion is a tiny, invisible white dwarf.

To the northwest, the third corner of the Hexagon is occupied by Castor and Pollux, the twins of Gemini. Between the twins and Procyon lies bright yellow Saturn, which will be much in the news later this month when the Huygens probe lands on its moon Titan.

Pollux, a magnitude-1.1 star 33.7 light years distant, glows orange. Farther, dimmer Castor--magnitude 1.6 at 51.5 light years--appears white to the eye. Through a telescope Castor becomes three stars, and though not visible each of these is a double for a total of six suns looking like one to the naked eye.

Above and right of the Twins is Capella, the fourth corner of the Hexagon and the sky’s sixth brightest star at magnitude 0.1. It shines from 41 light years away in Auriga the Charioteer.

Lower and farther right is Aldebaran, the red eye of Taurus the Bull, occupying the fifth spot at 60 light years away and magnitude 0.9.

Completing the Hexagon is Rigel, brightest of stars in Orion and just right of his belt. Even though it is some 1,400 light years away, Rigel still shines at magnitude 0.5, making it seventh brightest as seen from Earth.

While Rigel officially ends the lap around the Winter Hexagon, many find it natural to make a sharp left to finish up at magnitude 0.5 Betelgeuse, which also sits some 1,400 light years distant. This red giant is nearing the end of its life, making it a prime candidate to go supernova.

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This column originally appeared in the Visalia (Calif.) Times-Delta on Jan. 6, 2005.

Something's Missing from the Night Sky

2004-12-01T00:00:00.000-08:00

Something's Missing from the Night Sky
by Dave Adalian

Something is missing from the night sky.

Looking north just after dark in December, stargazers will find the familiar Big Dipper of Ursa Major gone.

It hasn’t vanished. The well-known asterism is now at its lowest and most northerly for the year, so that it hangs partially hidden behind the horizon and the trees, buildings and mountains that obscure it. This is the season when whatever celestial liqueur it is that passes between these stellar vessels flows from the Little Dipper of Ursa Minor into its greater counterpart.

It may seem strange to think of the Dipper as anything other than itself, but these stars have almost as many names as there have been cultures of men gazing up at them.

It could be the low, late-autumn sweep--which sends the Dipper’s stars cutting into the earth--that prompts Britons to call the group of seven bright stars the Plow. Across the English Channel, the French call it the Saucepan.

Of course Greeks and Romans saw the Great Bear that gave us the name Ursa Major, but several other cultures around the ancient world did, too. Micmacs of North America see the four stars of the Dipper’s bowl as the feet of a bear that slowly circled the North Star. Iroquois imagine a group of hunters following a bear.

The Chumash of the Central Coast tell a story of seven boys who ran away from homes where they weren’t wanted and turned into geese, and Pawnee legend describes a sick man carried on a stretcher.

Many cultures have seen the Big Dipper as a wagon. Norse myth puts Thor at the reins, while Germanic legend says it belongs to his father Odin. Coming full circle, the Chinese version includes a horse-drawn wagon for the celestial emperor on the back of a bear.

While the Big Dipper is low after sunset, it rises quickly to stand on its handle by 10 o’clock. This happens earlier each night as we move into winter.

The middle five stars of the Dipper comprise an open cluster, all of them moving together through the galaxy. This cluster, at 75 light years to its nearest sun, may be the closest to Earth. Or not. Sol moves in nearly the same way, leading some astronomers to conclude we may be part of the cluster ourselves, our star forming from the same dust cloud as those of the Big Dipper.

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This column appeared originally in the Visalia (Calif.) Times-Delta in December 2004.

A Season of Long Nights

2004-11-01T00:00:00.000-08:00

A Season of Long Nights
by Dave Adalian

As autumn ripens after the October rains and fog, a season of long nights begins. Day turns to evening during the dinner hour and skies darken early for digestive strolls spent wandering with the stars.

With no moon this week, nights will be dark and starry. Walkers will notice the Summer Triangle of Vega, Altair and Deneb still riding high in the west after sundown, while at the same time, the Great Square of Pegasus shines in the east. Already well up in the sky, by the end of the month the Square will be overhead just after dusk, a telltale of the coming of winter.

Alpheratz, the star marking the northeast corner of the Great Square, is actually the brightest in the constellation Andromeda. This willowy arrangement of stars represents a celestial princess awaiting rescue by Perseus, the Greek hero who slew Medusa. Not far to the northeast of Alpheratz, look closely to find the faint wisp of that is the Great Andromeda Galaxy, one of the Milky Way’s closest neighbors at only 2.9 million light years distant. It is the farthest object that can be seen by the unaided eye.

The constellation Perseus itself lies farther to the northeast of Andromeda, a riot of stars sitting just below the W of Andromeda’s mother Cassiopeia. Below it and to the right are the wonders of Taurus the Bull discussed here last month--the Pleiades, the Hyades and the bright red giant star Aldebaran.

The Moon returns to the early evening sky in mid-month, appearing briefly as a thin crescent in the southwest the nights of Nov. 15 and 16, when it will sit in Sagittarius.

Each month the Moon traipses through the Zodiac, rising earlier night to night and making the stars seem faint by comparison as it brightens. By Nov. 17 Luna is amid the dim stars of Capricornus, the Sea Goat. Two nights later it’s well into Aquarius, the Water Barer, and on Nov. 22 it swims with the fishes of Pisces.

By Nov. 24, the almost full Moon sits in Aries the Ram, a group of dim stars remembered because of its association with astrology. Aries’ three brightest stars, representing the ram’s horns of plenty, sit directly above the Moon this night before Thanksgiving.

The Moon is in Taurus when full two nights later, then finishes the month with the twins of Gemini, rising just after dark.

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This column appeared originally in the Visalia (Calif.) Times-Delta in November 2004.

Taurus Marks Return of Fall

2004-10-01T00:00:00.000-07:00

Taurus Marks Return of Fall
by Dave Adalian

Astronomers mark the Valley’s slow decent into autumn not by the colors of the leaves and a drop in the mercury alone. They watch too for the return of Taurus the Bull to the night sky.

This compact constellation of the Zodiac rises in the east just after sunset during October, bringing a dazzling string of astronomical delights as it stampedes over the horizon.

First to rise is the Pleiades, those famous Seven Sisters the Japanese call Subaru. This compact group of stars--an open cluster some 380 light years distant--dazzles the eye with hot, white stars that shine and twinkle like diamonds through the Valley haze of walnut dust and cotton defoliant.

From the city the best one can hope to see are the six brightest stars of the Pleiades in a shape some people mistake for the much larger Little Dipper of Ursa Minor in the north. A dark night in the countryside will push that number to about nine, while getting above the smog will produce as many as a dozen for the naked eye when the Moon is new.

In total, the cluster contains some 500 stars, many of which can be seen in a backyard telescope.

Below the Sisters and rising about an hour later is Taurus’s less famous open cluster, the Hyades. This V-shaped cluster is perhaps the closest one to Earth at 150 light years distant. The Hyades, another group of sisters from Greek mythology who died from grief for their brother Hyas, represent the face of Taurus.

At the end of the eastern arm of the V is the bright red star Aldebaran, which marks the angry, bloodshot eye of the charging bull. While Aldebaran appears to be part of the Hyades cluster it is actually less than half the distance at just 60 light years.

Telescopes reveal another treasure of Taurus lost to those with unaided eyes. Rising after the Hyades comes the Crab Nebula, the remains of an exploded star that dazzled during the nights of 1054 A.D. The event was reported by Chinese astronomers, and natives of the American Southwest depicted it on canyon walls.

Taurus holds one last charm for those who scan the autumn night--a minor meteor shower. The Northern Taurids begin the second week of October and last through the start of December, displaying a handful of bright shooting stars every hour from between the horns of the bull.

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This column originally appeared in the Visalia (Calif.) Times-Delta in October 2004.

A Black Hole Sits at the Center

2004-09-02T00:00:00.000-07:00

A Black Hole Sits at the Center
by Dave Adalian

A monster lurks at the center of our galaxy.

It carries mass 300 times greater than our Sun, dominates an area 250 million miles across and grabs everything that comes near. It never lets go.

This beast is properly known as a singularity, but most people just call it a black hole.

The name fits.

Black holes are areas of space from which nothing, once it enters, ever escapes. It is the stuff of nightmares. Don’t panic, though. This monster is 30,000 light years away and poses no problem here in the Milky Way’s suburbs.

Black holes are invisible, but we can detect them by their silhouettes. These one-way doors through the fabric of space-time start life as run-of-the-mill supernovae, those explosions that come at the end of large stars lives. What’s left after the star explodes then collapses, giving up the structure of normal matter and forming a super-dense star made up of particles called neutrons. A teaspoon’s worth of such a star would weigh more than all the cars, buses and trucks on Earth.

If the original star is large enough before it bursts into supernova--about 2.5 times the mass of Sol--the collapse continues past the neutron-star stage and the leftovers shrink to a single point with infinite mass yet no length, width or height--a black hole.

Singularities can’t be seen because not even light moves fast enough to overcome their pull. On Earth, anything moving faster than seven miles a minute, like a moon rocket, can leave the planet forever. Black holes’ gravity is so strong that even the speed of light--the fastest speed possible at 186,000 miles a second--is too slow to make a getaway.

While we can’t see a black hole for ourselves, we do know where to look if we could. That monster at the center of our galaxy, called Sagittarius A* (pronounced Sagittarius A Star), lies just off the end of the spout of the Teapot discussed here last month.

This month the Teapot sits due south on the horizon at nightfall. To find Sagittarius A*’s spot in the sky, follow the line from the star that marks the top of the Teapot’s body to the one that marks the tip of its spout. Continue that line about the same distance as the marker stars are apart, and there is the center of the galaxy and the lair of that ever hungry stellar beast.

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This column originally appeared in the Visalia (Calif.) Times-Delta on Sept. 2, 2004.

Meteor Showers Peaking

2004-08-05T00:00:00.000-07:00

Meteor Showers Peaking
by Dave Adalian

"Reliable" is a word not usually associated with meteors, but that’s exactly how astronomers like to describe the Perseid meteor shower that peaks next week.

Conditions for meteor viewing should be just about perfect Wednesday night, Aug. 11, with a thin crescent of a Moon not rising until the wee hours. The actual peak of the shower will come about four hours after midnight on the morning of August 12, and midnight to dawn will give the best views. But, the Perseid shower’s peak is a wide one so beautiful displays may be available from dark skies as soon as the Sun has completely disappeared.

This peak is so wide many meteors are visible a night or two before and after the peak. Meteors from this shower began appearing in late July, so those eager to get started might even catch a handful tonight before moonrise.

Average counts for experienced meteor observers have been in the range of 60 meteors an hour for the Perseids during the hours between midnight and dawn on the night of the peak. Those who predict the intensity of meteor showers say this year might bring a higher rate since Jupiter has perturbed the stream of debris that causes the shower, pushing it closer to Earth.

As always, the darker the sky above, the better the viewing below, so the best places to observe meteor falls are in the countryside, foothills or mountains.

Brighter members of the shower will probably be visible even under city lights. So, too, will be several of the brighter constellations, including the Teapot of Sagittarius in the south and to its right the scorpion of Scorpius. Overhead is the bright star Vega in the constellation Lyra. Vega, along with Deneb and Altair, create the brilliant Summer Triangle.

North is the easily recognizable Big Dipper of Ursa Major and to its right the North Star marks the end of the Little Dipper’s handle. If city skies are dark enough all seven of the Little Dipper’s dim stars might be available to the naked eye.

To the Little Dipper’s right is the bright W asterism of the constellation Cassiopeia and below that is Perseus, the star-studded constellation for which the Perseid meteor shower is named. The point where the Perseids appear to originate is between these two constellations, and around this area is the best direction for Perseid hunters to gaze.

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This column appeared originally in the Visalia (Calif.) Times-Delta on Aug. 5, 2004.

Marvelous Milky Way

2004-07-08T00:00:00.000-07:00

Marvelous Milky Way
by Dave Adalian

Cloudy nights are usually the bane of celestial sightseers but not always, not this time of year.
Recently a non-astronomer friend and I were stargazing from a dark site east of Exeter when he announced our session might be coming to an unplanned end.

“Look,” he said, pointing to the southeast, “some clouds are coming in.”

Instead of disagreeing, I pointed binoculars at the supposed storm front and let him have a look. He was quiet for a long time.

“What do you think?” I asked.

“That’s a lot of stars.”

My friend had discovered the Large Sagittarius Star Cloud, a hole in the dust that hides the bright edge-on view of our galaxy from Earth. What he was seeing that night were millions of stars in the Sagittarius Spiral Arm of the Milky Way.

As I mentioned last month, eight bright stars in the constellation Sagittarius form an asterism called the Teapot. It rides low in the southeast just after sunset, and the Moon can be used to find this stellar shape. On the night of July 27 the Moon sits to the right of the Teapot and the next night covers the Large Sagittarius Star Cloud.

It takes a moonless night far from town for finding the cloud that fooled my friend, but it’s worth the trip. This is especially true since the Large Sagittarius Star Cloud marks the gateway to one of the most beautiful stretches of night sky.

The cloud sits at one end of a white river of stars that cuts across the summer sky, Earth’s view of the Milky Way Galaxy. It’s easy to think of it as steam pouring from the Teapot’s spout.

The steam trails in wisps up and to the left of the Teapot. Besides the bright nebulas I listed last month, observers will also find the Small Sagittarius Star Cloud easily with the naked eye from a dark site. The smaller cloud is another hole through the dust.

Climbing along the trail of stars, are dark patches of dust and dozens of star clusters seen easily without optical aid. With binoculars, this trek is one of the sky’s best hunting grounds.

Before the trail ends at the other side of the sky, it meanders through another landmark of the summer sky, the Summer Triangle, a huge asterism formed in the east by the three bright stars Vega, Altair and Deneb.

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This column originally appeared in the Visalia (Calif.) Times-Delta on July 8, 2004.

Sibling of the Sun

2004-06-08T00:00:00.000-07:00

Sibling of the Sun
by Dave Adalian

The Sun once had a big sister.

Sol’s sibling is long dead, but as it went it may have given Earth the gift of life.

According to evidence presented at Arizona State, the Sun and its satellites were born in a shock wave caused by radiation from a huge star.

When that giant sun sparked to life 4.6 billion years or so ago, intense ultraviolet light poured into the nebula surrounding it, compressing and ionizing its gas until smaller stars formed.

Radiation from the Sun’s giant relative blasted away anything that couldn’t withstand its force, leaving just the Sun and the proto-planetary disk from which our world and the rest of the Solar System eventually formed.

Huge stars burn bright and live short lives. Sol’s older and much bigger sister’s life came to a relatively quick end in a supernova, scouring surrounding star systems with heavy elements formed by the pressure of the explosion.

Some of these elements were necessary for life. Others were radioactive, and the ASU researchers think the heat could have been responsible for the amount of water on Earth today. Also, the way Sol’s sibling exploded and its distance effected the type of planets that eventually formed.

The stars born in the stellar nursery with Sol drifted apart until today our closest neighbor is 4.2 light years away; and it may not be related at all.

This amazing and beautiful process of star formation is pictured in the famous Hubble Space Telescope image of the “Pillars of God” in the Eagle Nebula.

You don’t need to rely on the Hubble to see these magnificent deep space stellar nurseries. A host of them, including the Eagle, are visible in the area in and around Sagittarius.

In late spring and early summer, Sagittarius rises in the southeast an hour or two after sunset, following the familiar hooking shape of Scorpius.

A few of the stars of Sagittarius form the Teapot, and the only easy naked-eye nebula, the Lagoon, sits directly above it. It can be found from a dark spot amid the star clouds of the Milky Way.

Binoculars will reveal several others, including the Eagle, the Trifid and the Omega nebulas, along with a host of star clusters and fields. The area is one of the most beautiful in the sky for small optics.

Telescopes best show these delicate star-forming regions, revealing detail not otherwise available.

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This column originally appeared in the Visalia (Calif.) Times-Delta on June 8, 2004.

Don't Take the Moon for Granted

2004-05-11T00:00:00.000-07:00

Don't Take the Moon for Granted
by Dave Adalian

The Moon may be the most taken for granted object in the night sky.

It just sits there. Always has, always will.

Or will it?

Actually, the Moon is slowly moving away from Earth, but no need to panic. The rate of creep is just over one and a half inches a year. Since the Moon has an average distance from Earth of about 239,000 miles, it takes lots of years before those inch-and-a-halves make any difference.

Nice to know Luna’s not just sitting there.

It’s really pretty lively. The Moon moves closer and further from the Earth each month because its orbit is not perfectly round. These extremes--called apogee at the furthest and perigee at the closest--are noticeable in the Moon’s size and brightness, especially in photographs.

It’s also nice to know the Moon will never break free.

The complicated ballet of physical forces caused by the Moon’s orbit around the Earth is also making Earth turn more slowly as the Moon moves away. A similar effect between the Earth and Sun will eventually force the Moon back toward Earth.

If left alone long enough, the Moon would eventually move too close and be destroyed, however, the Sun will expand into a red giant star, swallowing Earth and Moon long before that can happen.

Earth hasn’t always had a moon. When Earth was very young, some four billion or more years ago, an object about half its current size struck it. According to this account, the Moon formed from the debris.

The Moon, at 2,000 miles wide, is by far the largest satellite in the Solar System compared to its parent body. Because of this similarity in size, Earth and the Moon are considered a two-planet system.

Research suggests the Moon was once much closer to the Earth and appeared much larger in the sky. Since then, it has drifted to its current spot and its spin has slowed so much the Moon turns only once every time it moves around the Earth and we see only a single side. The other remains forever hidden to the earthbound.

The most obvious change in the Moon are its phases, which are listed each day in this paper. The phases are a result of the changing relative positions of Earth, Moon and Sun. Try looking in on Luna every night through May and into June, witnessing her transformation as it happens.

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This column originally appeared in the Visalia (Calif.) Times-Delta on May 11, 2004.

Meteor Shower Coming

2004-04-06T00:00:00.000-07:00

Meteor Shower Coming
by Dave Adalian

Though it didn’t get much press at the time, an astronomical record was broken a few weeks ago. On March 18, asteroid 2004 FH missed us, whizzing by just 26,500 miles away, about three and a half times Earth’s width, and coming closer than any other recorded pass.

Whew!

Asteroid 2004 FH was just a little guy--only about 100 feet across--technically a meteoroid, if a very large one. Had it struck home, it likely would have exploded in the atmosphere, breaking windows and knocking pictures off the walls or more probably making lots of waves in some remote corner of the ocean.

But, it would have been one heck of a sight.

The difficult part about observing meteors is knowing when they’re going to arrive. They just aren’t reliable most of the time. This year, however, is going to be better than average for seekers of shooting stars.

Almost all of the major showers in 2004 will be free of moonlight, making even the dimmest meteors stand out when viewed from a properly dark environment. The excitement gets underway this month.

The Lyrids meteor shower peaks at 10-15 meteors an hour around 9 o’clock on the evening of April 21. Adding to the show will be another 10-15 sporadic meteors or so every hour streaking randomly across the sky.

Observing meteors is a wonderful way to get into astronomy since it requires no expensive optical equipment. It does, however, require some preparation. The smart shooting-stargazer will dress warmly for a long night under the stars. It’s also best to have a jug of hot coffee and snacks standing ready.

Of equal importance is posture. Sitting up or standing just won’t cut it. After a short time of bending the neck skyward fatigue sets in, so meteor watching is best done from a reclined position in a low-slung chair or lounge.

Showers are named after the constellation from which the meteors appear to come. To make the most of the show viewers should be sure they can see the spot the meteors are coming from and the zenith, the spot that marks the top of the sky.

For April’s Lyrids, that means pointing your toes toward the northeast.

Here is a list of other best bets for meteor watching in 2004:

The Ophiucids, June 20
The Perseids, August 11
The Orionids, October 18-25
The Leonids, November 16
The Geminids, December 13

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This column originally appeared in the Visalia (Calif.) Times-Delta on April 6, 2004.

Catch Mercury at Sunset

2004-03-09T00:00:00.000-08:00

Catch Mercury at Sunset
by Dave Adalian

Of the nine planets in our Solar System, only five are easily visible to the naked eye. This month, those with keen vision may see them all in a single evening.

The hardest to locate of the five wanderers--the Greek root of “planet” means “one who wanders” as the planets do when they slide among the stars from night to night--is swift-footed Mercury, messenger of the Gods.

Mercury is difficult because it rides so close in the sky to the Sun. During the last half of March, however, it will follow far enough behind the sunset to let those who try catch a fleeting glimpse.

The lucky can see Mercury anytime during the last 10 days of March or first few days of April, riding low in the gloaming of the western sky around 6:30 p.m. The job is made easier the evening of Monday, March 22, when a brand new crescent Moon sits above Mercury and to its left. It may even offer a little color to the eye.

Much easier to find--almost impossible to miss--is bright Venus. As I described last month, Venus is still scintillating in the high western sky just after sundown, outshining all other heavenly bodies but Moon and Sun.

The still young crescent Moon will slide past Venus the evening of March 24 in a breathtaking close pairing. Even the cheapest of binoculars will make the sight spectacular.

Just above Venus are the Seven Sisters, a familiar cluster of bright stars known as the Pleiades. Beside them is a single dim point of red light, all that remains of the brilliant Mars of last summer. Mars is now so far diminished its details are lost even in the telescope.

Saturn, on the other hand, it still at its best for viewing with or without optical aid. It sits almost at the top of the sky when darkness settles in, resting between the stars of Orion and the bright twins of Gemini, Castor and Pollux. In a telescope, its vaguely yellow color becomes a beautiful tawny golden, its rings open wide and its moons surround it.

Also astonishing when seen in the telescope is Jupiter, king of the planets. Magnified, Jupiter becomes a striped disk of swirling colors surrounded by its bright moons and sometimes highlighted by the Great Red Spot. It can be found rising in the east with the constellation Leo.

Clear skies!

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This column originally appeared in the Visalia (Calif.) Times-Delta on March 9, 2004.

Love Lingers on Horizon

2004-02-10T00:00:00.000-08:00

Love Lingers on Horizon
by Dave Adalian

Those looking for love on Valentine’s Day will have an easy job of it--all they need do is turn to the west at sunset.

What they’ll find there is the brightest of the nine planets, Venus, blazing boldly in white as the Evening Star, outshining everything else in the sky but Sun and Moon.

To the Romans, Venus was the goddess of love, presiding over affairs of the heart. It is her blindfolded son, Cupid, with his bow and arrow who is responsible for so much joy and sorrow here on Earth; “Cupid” comes from the Latin cupido, which translates as “desire.”

While Venus is already a spectacular sight during the three hours after dusk, she’s still only warming up. She’ll continue to climb a little higher in the western sky each night until March 28, when she reaches greatest eastern elongation.

Though no farther away from the Sun that day than any other time during her 225-day orbit--the roundest one in our Solar System--Venus will then appear as far from the Sun as she can, as seen from Earth.

Earth and Venus are almost twins in size. Venus is 202 miles thinner at the waist than Earth, but carries only 85 percent as much mass. This may be due to losing her water into space.

Besides being drier than any desert on Earth, Venus is absolutely hellish. At the surface, the pressure of her carbon dioxide atmosphere is equal to being six-tenths of a mile underwater, and the sky is covered perpetually beneath clouds of sulfuric acid.

Those clouds have started a runaway greenhouse effect on Venus, raising temperatures to nearly 900 degrees--easily hot enough to melt lead.

Cloud cover also causes Venus to shine so brightly. The miles-thick layers of sulfuric acid clouds are extremely reflective, bouncing back most of the sunlight that strikes them.

Because Venus orbits closer to the Sun than Earth, she appears to us to go through phases like the Moon. Now, she looks through a telescope to be slightly pregnant. As March 28 approaches, Venus will slim to last quarter. In weeks following, she’ll diminish to a sliver as she slips deeper into twilight each night.

Some, myself included, claim to have seen the shape of Venus with naked eyes. A good night to try this may be Feb. 23 when Venus shares the sky with a thin crescent of new Moon.

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This column originally appeared in the Visalia (Calif.) Times-Delta on Feb. 10 , 2004.

Giant Looms at Night

2004-01-13T00:00:00.000-08:00

Giant Looms at Night
by Dave Adalian

An ancient giant dwells in winter’s night sky, a creature old as myth.

As long as man has recognized this nocturnal titan in the stars we have called him The Hunter. Ancient Greeks first gave him the name we use today--Orion, literally “mountain man.” Even then he was already older than the hills.

Sumerian and Babylonian legends call the giant Enkidu, a tamed wild-man companion of fabled Gilgamesh. Doubtless the myth carries back to a time the stars of Orion marked a stone-age hunter-god whose name is now long forgotten.

This month Orion dominates the sky deep into the night. Already above the eastern horizon by sunset, the Hunter sits high, directly southeast by half past seven.

Stargazers easily recognize the constellation’s lopsided rectangle of bright stars. It surrounds a short line of three brilliant, white suns--the Belt of Orion. Together they form a butterfly or bow-tie shape.

Most striking of Orion’s suns is famous Betelgeuse, the bright red-giant that marks the Hunter’s eastern shoulder. At the western shoulder shines Bellatrix, and diagonally across from it Saiph shows as the western foot.

Orion’s other foot is the white jewel Rigel. Draw an imaginary line from Rigel through Betelgeuse and it goes through the dim stars of Orion’s raised club in his right hand before passing beside Saturn in nearby Gemini.

A long arc of dim stars west of Bellatrix shields Orion from Taurus the Bull. The bull stands between him and the object of his desire, Merope, brightest of the Seven Sisters in the Pleiades.

Another imaginary line drawn through Orion’s Belt from west to east passes next to Sirius. This brilliant white diamond at the shoulder of Canis Major shines brightest of all the stars seen from Earth.

Another cluster of what looks like three stars in a row lies just south of the belt. Faint fuzziness around the middle star betrays its true form: this is the Great Orion Nebula. Visible even to the naked eye, in the telescope it becomes a specter with writhing tendrils edged by hints of green and red. It is a wonder in binoculars, too.

Orion reaches his highest near ten o’clock and stands due south. From there he drops into the west to set in the cold, still hours before dawn. As he does, Scorpius, his mortal enemy who may never share Orion’s sky, rises in the east just before the Sun.

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This column originally appeared in the Visalia (Calif.) Times-Delta on Jan. 13, 2004.

Return of the Rings

2003-12-16T00:00:00.000-08:00

Return of the Rings
by Dave Adalian

Somewhere in the cold and empty void beyond the orbit of Jupiter a spacecraft is racing toward a long-awaited rendezvous.

Seven years ago NASA and the European Space Agency’s Cassini-Huygens Mission to Saturn left Earth. Twice it swung past Venus, once returned by Earth, and finally it flew past Jupiter on the way to its destination. Cassini is scheduled to enter orbit around the ringed gas-giant planet on July 1 of next year.

When the probe arrives, it will transmit back to Earth new information about the ringed world and its largest moon, Titan. Titan is the only moon in the Solar System with a thick, planet-like atmosphere, and the Huygens portion of the probe will drop below it to the surface to see for the first time what lies underneath. Perhaps lakes or oceans of liquid methane.

Potentially glorious pictures of Saturn’s 150,000-mile wide rings, its stormy atmosphere and the other lesser moons will also be captured by Cassini--the most complicated robotic probe mankind has built.

As intellectually stimulating, scientifically important and just plain exciting as that is, all the images and data in the world don’t rival viewing Saturn with one’s own eyes as it moves through the night. Now through March is the best time for doing just that.

Saturn seems to know 2004 is its year, and is planning a New Year’s celebration. Like Mars before it last August, Saturn is coming to opposition--the time of year when it appears to be opposite the Sun in the sky and is closest to Earth--on New Year’s Eve.

Because it is at opposition, Saturn rises on Dec. 31 as the Sun sets, around 4:45 p.m.

By 9 o’clock it is well up in the east, shining bright yellow from its perch in the zodiacal constellation Gemini. To Saturn’s left are the twin stars Castor and, slightly east, Pollux.

As the year turns at midnight, Saturn appears to be on the imaginary meridian line joining north pole to south, signaling our longitude--119 degrees west--is at its closest to the ringed planet for this pass. Saturn is about 800 million miles away.

This view is made truly spectacular by the current angle of Saturn’s rings, almost completely open toward Earth. A telescope will show the rings and perhaps details within them. If you haven’t got a telescope, find someone who does. It’s worth the effort.

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This column originally appeared in the Visalia (Calif.) Times-Delta on Dec. 16, 2003.

Generous Skies All through November

2003-11-18T00:00:00.000-08:00

Generous Skies All through November
by Dave Adalian

November is a traditional time of plenty on Earth, and this month the generosity extends itself into the skies.

As I mentioned last month, Venus has retaken her place as the Evening Star for the holidays, becoming the brightest of the visible planets as the year dwindles. This week, she sits low--almost due southwest at sunset--shining bright but sinking fast.

The Evenstar will be easier to spot on Tuesday, Nov. 25, when a brand new crescent Moon, just a sliver really, sits to her left. It will take a keen eye to spot so slim a Moon. Those who do may notice how bright the normally dark part of the Moon seems. That’s earthshine reflecting back at us from the shaded lunar surface.

During the last days of November, Venus follows another bright planet, swift Mercury, into the gloaming. Mercury is called quick with good reason; if you don’t get a look at him in early December, he’s lost in twilight by mid-month. For those two weeks, he’ll be below and to the right of ever brightening Venus.

While waiting for Mercury to make an appearance, take time to revisit a now much weakened Mars. The Warrior God is only about one-tenth as bright as at his height three months ago. High in the southeast at dusk, Mars sets not long after midnight. Luna will visit him on Nov. 30 and Dec. 1.

By about 10 o’clock, Saturn is high in the east among the bright stars of Gemini. Like Mars before him, Saturn is gathering for a close pass by Earth on New Year’s Eve. He still shows few obvious signs to distinguish him from a star. Best to let the Moon point Saturn out when she sits directly above him on the night of Dec. 9, then to his left on Dec. 10.

With Saturn’s rings still open and reflecting sunlight in our direction, the Bringer of Death with its dirty yellow glow is a bright and stunning sight through the telescope. See it this month or next as it won’t be this spectacular again until 2030.

The King of Planets is still better for morning larks than night owls as winter approaches. Although it rises now not long after midnight, it isn’t until the last hour or two before dawn Jupiter is best. The Moon marks Jupiter and the constellation Leo in the early morning Dec. 16.

Clear skies!

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This column originally appeared in the Visalia (Calif.) Times-Delta on Nov. 18, 2003.

Tricks and Treats in the Sky

2003-10-21T00:00:00.000-07:00

Tricks and Treats in the Sky
by Dave Adalian

When little witches, ghosts and evil things that tarry in dark places go abroad this Hallowe’en, treats better than those in plastic wrappers await trick-o-treaters who turn their eyes skyward.

If they can find a clear view west as they go from door to door, those who come out early on Oct. 31--just a few minutes after sundown--might catch a view of Venus shining low on the horizon as the Evening Star.

Venus climbs higher off the horizon each night during autumn, reaching its highest point near winter’s end then sinking back into the west in spring. Look for Mercury to join Venus in time for Christmas.

A Moon only a few hours shy of first quarter will be due south at sunset on the last day of this month, haunting the dim, V-shaped constellation Capricornus, the Sea Goat. East of the Moon, a lingering Mars holds only about half the luster it showed back in August. Still, it shines brighter now than everything else but the Moon.

Moving east and growing larger night-by-night, the Moon passes Mars on Nov. 2-3 and slips into Aquarius, the Water Bearer, another indistinct and sprawling constellation of the fall Zodiac. The only bright star there is Fomalhaut (FOAM-A-LOW), appearing yellowish-white near the horizon below Mars.

The Moon grows to full the night of Nov. 8, but when it comes up that evening it might not be there to be seen. The second total lunar eclipse of 2003 begins at 3:23 p.m. that Saturday, well before the Moon rises here in the West. But, totality, when the entire disk of the Moon is shrouded by the darkest part of Earth’s shadow, doesn’t happen until 5:06 p.m., just as the Moon is rising here.

For the first half hour of its journey across the sky, the Moon will be hidden. Eclipsed moons are notorious for their strange colors. Last May’s seemed to be pale and washed out. How will this one compare? Perhaps orange or bloody red or something more like the color of fading Mars.

Pay attention to the shape of the Earth’s shadow as the Moon emerges, beginning around 5:31 p.m. Though fuzzy at the edges, Earth’s shadow is distinctly round, proof positive if you need it we live on a sphere.

By 8:15, October’s Frost Moon will be shining bright again during the rest of a long autumn night.

Clear skies.

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This column originally appeared in the Visalia (Calif.) Times-Delta on Oct. 21, 2003.

Mars Didn't Fall Short

2003-09-23T00:00:00.000-07:00

Mars Didn't Fall Short
by Dave Adalian

As the whole world watched last month, Mars swung closer to Earth than ever in recorded history. It was quite the event.

Observatories all over were awash in a sea of visitors eager for a glimpse of the Red Planet as it passed. The Purcell Observatory in Tulare was certainly no exception, as record numbers turned up for a gander through the telescopes.

Mars didn’t disappoint. It might even have been showing off some. I’ve certainly never seen it look better. Neither has anyone else.

Unfortunately, those who didn’t see Mars at its absolute best in August won’t get another chance for 284 years.

Good news though: The 2003 show isn’t over!

Mars is still looking very good. A peek at it through a telescope this week won’t be rivaled until 2018. Members of the Tulare Astronomical Association will host a public star party Sept. 26, free of charge as always.

Those who don’t have a scope and can’t make the party should try taking in the many sights that need no optics during this season of summer’s retreat.

Mars is still a naked-eye beauty, already riding high in the southeast as the Sun sets. As the days pass and Mars moves away, watch carefully to notice its yellow-red glow grow dimmer night by night. On the nights of Oct. 5 and 6, it will be joined by the nearly full Hunters Moon.
After sunset at this time of year is when three bright stars--Vega, Deneb and Altair--sit straight overhead at the top of the sky. These stars form the Summer Triangle, a figure which surrounds a bright patch of Milky Way glow visible from here in town when the neighbors’ lights are low and the Moon is down.

Around an hour before midnight and earlier each night, the Seven Sisters of the Pleiades sparkle to the east. To see more than six of these young, hot blue-white stars in Taurus will require a trip into the countryside.

By midnight the first stars of Orion the Hunter rise in the east, and by 2 a.m. the familiar winter constellation is well above the horizon. To the left of Orion’s famous red star Betelgeuse is another bright point of light, one that unlike other stars doesn’t twinkle. This is Saturn.
Watch Saturn rise earlier and climb higher as the fall nights grow longer and the cold begins to linger.

Clear skies.

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This column originally appeared in the Visalia (Calif.) Times-Delta on Sept. 23, 2003.

Mars Makes Close Approach

2003-08-26T00:00:00.000-07:00

Mars Makes Close Approach
by Dave Adalian

When practicing a hobby like astronomy once-in-a-lifetime events happen all the time. But, three hours after midnight tonight is a very big event indeed.

At 2:51 a.m. on August 27, Mars will be closer to Earth than during all of recorded human history.

While experts disagree on when Mars was last this close, all estimates put the number at longer than people have been keeping track of things like this or anything else. Reliable numbers put the date at 60,000 years, give or take a long weekend.

In any event, this is a really exciting time for stargazers of all level. Unfortunately, Mars Fever doesn’t seem to be spreading as it should. Maybe it’s because those in the know tend to call big events like this by silly names. We call this one an opposition.

Earth and Mars are like runners on a track, with Earth on the inside lane. About every two years we pass Mars by, and because the orbits aren’t perfect circles, we pass closer at some times than at others. This go-round, the Red Planet will be a scant 34.6 million miles away.

These close passes coincide with Mars’ opposition, the time when the Sun, Earth and Mars align, and Mars sits opposite the Sun in the sky. What makes the 2003 opposition a truly big deal is Mars will be bigger and brighter than any living observer has ever seen it.

To see Mars at its finest, step outside an hour or two after sunset tonight and look a little south of due east. Mars will be unmistakable, shining as the brightest and reddest “star” in the sky.
As an added bonus, on Monday, Sept. 8, Mars will be joined closely in the sky by a nearly full Moon. Any pair of binoculars will really enhance the view.

Of course, the best look at the Red Planet will be in a telescope, but even then don’t expect exactly Hubble-like views. At 100X magnification, Mars will seem like a pea in a petri dish even though it will have the same apparent size as the full Moon when seen unaided. Even so, details like the polar ice caps, clouds and dark regions on and over Mars ruddy surface will be awesomely clear, especially when conditions allow for much higher magnifications.

One way or another, take a look at Mars sometime this week. Those who miss out will never get another opportunity like this one.

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This column originally appeared in the Visalia (Calif.) Times-Delta on August 26, 2003.

Moon May Outshine Meteor Shower

2003-07-22T00:00:00.000-07:00

Moon May Outshine Meteor Shower
by Dave Adalian

Some say a full Moon is the most romantic nighttime sight. Others say it’s shooting stars. In mid-August we’ll get both on one night during the Perseids (per-SEE-ids), the year’s most reliable meteor shower.

Falling stars aren’t really stars. Your run-of-the-mill meteor is caused by a tiny piece of rock--a meteoroid--the size of a grain of sand with the consistency of ash. They vaporize high in the atmosphere as friction from their tremendous speed causes them and the air around them glow briefly and brightly.

Most of the time they arrive sporadically, a couple every hour more or less. Periodically the rates climb, putting on a spectacular show if conditions are right.

The random bits of debris are crumbs from ancient collisions among comets and asteroids. Left floating for billions of years, the pieces sometimes fall to Earth in blazing glory one at a time.
Meteor showers, however, are caused by Earth crossing the path of a large comet or asteroid. As these bodies loop around the Sun, they lose pieces of themselves which slowly drift ahead and behind until they spread throughout their parent’s orbit.

When Earth enters one of these streams and turns its night side toward the onrushing meteoroids, the fireworks begin.

On the night of August 12, we’ll be in the thickest part of the trail left by Comet Swift-Tuttle. When this happens, rates usually climb to 80 meteors or more an hour. In 1993, hourly rates at the peak were estimated at 200 to 500.

Unfortunately, August 12 is also the night of full Moon and our bright neighbor will outshine most of the show.

It’s still worth going out for a look. The Moon will be low when the shower peaks near 10 o’clock, so from a dark site we might see 20 to 40 meteors or more an hour. Or perhaps less or even none--meteor shower prediction is still a science in its infancy. But, surprises do happen.
To view the shower, set up a low-slung chair or lounge with your head pointing northwest--the opposite direction from a close pairing of the rising full Moon and bright orange Mars--and watch the skies overhead.

The Perseids’ radiant, the area where the meteors seem to come from, lies north in the constellation Perseus. The shower lasts from July 23 to August 22, with slightly increased meteor activity before and after the peak.

Clear skies!

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This column originally appeared in the Visalia (Calif.) Times-Delta on July 22, 2003.

Think About Light Speed

2003-06-24T00:00:00.000-07:00

Think About Light Speed
by Dave Adalian

My birthday is in July, making this a perfect time to talk about cosmic distances and the speed of light.

Make sense?

It does if you realize somewhere out there is a star as many light years away from Earth as I am years old.

While I’ve been living my life, going to school, working, getting married and having children, light from my birthday star been streaming across the universe at, well, light speed, of course. Light speed is the fastest anything can go, as far as we can tell, about 186,000 miles every second--more than seven trips around Earth’s equator every time your heart beats.

How far will the light from my birthday star have come to get to me?

For perspective, remember the Moon averages a distance from Earth of about one and a half light seconds.

It took our space ships four days each way to close that meager gap.

The Sun, at an average distance of 93 million miles away, is only eight minutes distant at the speed of light.

The furthest planet out from the Sun, Pluto, is only a scant five and a quarter light hours from us. The Voyager probes, the fastest man-made objects there are, passed that distance in about 12 years.

Far beyond that, marking the distant edge of the Solar System, is the Oort Cloud, a sphere of comets surrounding our sun at a distance of about one and a half light years, or somewhere in the neighborhood of nine trillion miles.

The Voyager probes will need about 40,000 years to get there.

Light from my birthday star will have come the better part of 214 trillion miles, and it’ll hit us just as I finish my 36th trip around the Sun--a nifty coincidence making the occasion seem more grandiose.

This year, my birthday star is 54 Piscium--a dim star in the constellation Pieces. I could have searched one of several lists of stars available in books and online to find it, but instead I used a clever little program at the Joint Astronomy Centre.
If you let the Centre do the work, you’ll also get a map of the sky you can use to find your birthday star. If you have trouble finding your star, I or one of my fellow amateur astronomers would be happy to help at the Tulare Astronomy Association’s monthly star parties.

Clear skies!

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This column originally appeared in the Visalia (Calif.) Times-Delta on June 24, 2003.

Strange Lights on Summer Nights

2003-05-27T00:00:00.000-07:00

Strange Lights on Summer Nights
by Dave Adalian

Summer is my favorite time of year. Nights are warm, and the starry sky is full of wandering lights--mysterious beacons in the sky. X-Files stuff.

OK, so these aren’t aliens coming to meet and eat mankind. But they are spacecraft. And they are watching us. The guys at the controls, though, are here on Earth and as human as you and me.

Until 1957, Earth had only one satellite, the Moon. In that year the Soviet Union launched Sputnik and since then some 27,000 manmade objects have been cataloged in the sky. About 9,000 or so are still in orbit, and a few hundred of them can be viewed with the naked eye.
This is the best time of year to see them. Earth’s seasons are caused by our planet’s tilt. When our hemisphere leans toward the Sun, the weather warms into summer. This slant makes Earth’s shadow fall low in the sky a few hours after sunset and before sunrise, leaving satellites exposed to the light and easy to see.

The only thing you need for satellite hunting is a dark, clear, moon-less sky like those we’ll have this weekend. The darker the sky, the better the hunting, but around here the backyard will do fine. What I like to do is lie back--in the swimming pool if it’s warm enough--let my eyes adjust to the dark, then wait until I see a star that’s come loose from its moorings drifting slowly across the sky before fading into Earth’s shadow. This time of year, I can easily catch a dozen or more roving lights before midnight, when Earth’s shadow grows tall.

Mostly, the lights are dim but steady points, like stars sailing slowly across the night. But, some are different. Iridium satellites, a group of communication repeaters, can flare up unexpectedly, quickly becoming the brightest thing in the sky before disappearing just as fast. Others flash on and off as they tumble through the sky. Mostly, these are old, dead machines falling uncontrolled through space.

One of the brightest satellites is the International Space Station. It appears regularly over the Valley, and you can find a schedule of its passes--and the passes of dozens of other manmade moons--at Heavens-Above.com. There you’ll find maps, instructions on how to use them and some details about what you’re seeing. You can also use the service to look up previous sightings.

Happy hunting!

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This column originally appeared in the Visalia (Calif.) Times-Delta on May 27, 2003.