Tuesday, October 28, 2008

Eldritch eyes in the sky watch over Halloween revelers

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.


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

Tuesday, September 23, 2008

Starry signs point toward fall

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.


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

Wednesday, August 27, 2008

Triple conjunction challenges eagle-eyed planet hunters

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.


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

Tuesday, August 19, 2008

Earth’s Seven Sisters are out this Week

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.


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.

Tuesday, July 01, 2008

War, Change and the Little King

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.


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

Sunday, June 01, 2008

Stupid Questions

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.


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

Thursday, May 08, 2008

Watch Mercury rise and fall all through May

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.


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

Wednesday, January 23, 2008

A Week of Wintertime Planet Watching

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.


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