Thursday, December 20, 2007

Planetarium Show January 11!

"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.

Tuesday, December 18, 2007

The Week Before Christmas: A Holiday Visit from Mars

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!


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

Saturday, December 01, 2007

Meeting Wednesday, Planetarium Show & Star Party Friday

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.

Thursday, November 08, 2007

A Long Look into the Distant Past

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.


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 or the Pena Planetarium website at


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

Tuesday, November 06, 2007

TAA to Meet Nov. 7

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.

Saturday, October 13, 2007

UC Berkeley Astronomy Lectures Online

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 and select the "/courses" link. The two astronomy courses are listed as Astro 10P and Astro C10/LS C70U.

Monday, October 01, 2007

Early Autumn is the Season of the Moon

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.


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.


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

Planetarium Show this Friday!

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.

Friday, September 28, 2007

Do Some Simple Science!

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.

Friday, September 14, 2007

Mars Really Is Looming Large

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?”


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.


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 or the Pena Planetarium website at


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

Thursday, September 13, 2007

Moon 2.0

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!


Monday, September 10, 2007

TAA at the Pena Planetarium

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

Wednesday, September 05, 2007

TAA to Meet Sept. 6

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.

Monday, August 06, 2007

Sky Dragon Swallows the Moon

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.


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


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

Saturday, July 28, 2007

TAA to Meet Aug. 2

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.

Saturday, July 14, 2007

Falling Stars on Hot August Nights

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.


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


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

Tuesday, July 03, 2007

TAA Monthly Meeting July 5

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.








Monday, June 25, 2007

Summer of the Planets Continues

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.


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

Tuesday, June 12, 2007

TAA July Meeting

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.


Thursday, May 31, 2007

TAA Annual Business Meeting June 5


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.

Monday, May 28, 2007

Mars Joins Planetary Parade

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.


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

Wednesday, May 23, 2007

Finding Neptune (and Uranus, too!)

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.

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

Sunday, May 20, 2007

Conjunction Images

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.

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:

Wednesday, May 09, 2007

Planetary Tour Starts Tonight

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.


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

Thursday, March 29, 2007

Venus Visits Star Sisters

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.


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

Thursday, February 15, 2007

Winter Skies Are Tricky

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.


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

Monday, January 15, 2007

A Ring Fire in the Sky

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.


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