Stargazing Without Stars

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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?

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

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

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.