Thursday, February 14, 2008

A Cosmic Valentine

My significant other is fond of saying that Valentine’s Day isn’t a day, it’s a season. This gives him the latitude to spread dinners and small gifts over the course of a week, rather than cramming it all onto February 14. Of course, I fully support this seasonal approach. I ain’t no fool (and neither, apparently, is he).

Since our observing week begins on Valentine’s Day, I will also take the ‘seasonal’ approach with my cosmic valentine to you. Here are seven romantic delights from the cosmos to spread over your week. They’re all visible in the current night sky, and they’re 100% guaranteed to make your heart flutter.

1) Messier 37. I think jewelry is always an appropriate valentine. With a single red giant star near its center, this sparkling star cluster in the constellation Auriga the Charioteer has been called “a ruby in a field of diamonds.” To find Auriga, look for a pentagon-like shape just north of the bright red planet Mars. Mars is nearly overhead about an hour after sunset. You’ll need binoculars to see this cluster. Train your binos on the spot marked M37 on the map below.

By the way, “Messier 37” is the name given to this object in the catalog of the famed 18th century French astronomer Charles Messier (pronounced MESS ee yay).

2) Rosette Nebula. May I offer you a red rose from the heart of space?

In the constellation Monoceros the Unicorn, ESE of the red supergiant Betelgeuse in Orion, lies one of the loveliest objects in the winter sky. This nebula (cloud of gas and dust) is a star-forming region, and the cluster of young stars in the center formed from the nebula only four million years ago. A small, wide-field telescope like the inexpensive Starblast Astro is a good match for this large nebula. You will need a dark sky and good transparency (atmospheric clarity) to see the nebulous ‘petals’ around the star cluster. Don’t expect to see any color in the petals; the red signature of this hydrogen-rich nebula can only be captured photographically.

An hour after sunset, you will find Orion in the south, about halfway between the southern horizon and the zenith, the point directly above your head.

3) Messier 79. What’s a Valentine’s Day celebration without a little sugar to sweeten the experience? Under Orion’s feet in the constellation Lepus the Hare is what looks like a galactic sugar pile. It is the globular cluster M79, a dense ball of gravitationally bound stars. There are 150 known globular clusters in the Milky Way, our home galaxy. This is one of my favorites; I like its whimsical star streamers. I hope you do too.

You will need a clear view of the southern horizon and a telescope to claim this globular. A small scope like the aforementioned Starblast Astro will net the object, and it will look like a small fuzzy blob. Using a larger scope like a six-inch reflector, you will begin to resolve the fuzz into pinpoint stars.

4) Saturn. Why should I give you just one friendship ring, when I can give you hundreds with a single object? Planet Saturn’s complex ring system is composed of billions of ice and rock particles, with each ring of rubble traveling in its own orbit. The ring system is remarkably thin: only half a mile thick compared to 175,000 miles wide!

You can spot golden-yellow Saturn with the naked eye. Around two hours after sunset, you should be able to spot it rising due east. It will be the brightest object near the eastern horizon, and its golden color should distinguish it from the stars in the vicinity.

5) Shooting Stars. Get thee to a dark site, away from city lights, to await your next cosmic valentine. You can see meteors, aka ‘shooting stars,’ every night of the year. A meteor is the streak of light we see in the sky when a bit of dust or space debris hits Earth’s atmosphere at high velocity. Increase your chances of seeing a meteor or two by lying on the ground or on a lounge chair, so that you can scan the greatest area of sky.

When you do spot one, make a wish. Think of it as a gift certificate from space; you can spend it however you like.

6) Venus. Since I can’t give you the Sun and the Moon, I’ll give you the next best thing: the next brightest object in the sky. Planet Venus, named for the Roman goddess of love, is currently lighting up the pre-dawn sky. The blue-white beauty rises in the ESE about an hour and a half before sunrise. Don’t confuse it with planet Jupiter, which rises from the same spot on the horizon, but about an hour earlier than Venus. Venus is also noticeably brighter than Jupiter.

7) Total Lunar Eclipse. Let’s finish out our observing week with an uncommon treat: a total lunar eclipse. A total lunar eclipse occurs when the Sun, Earth, and Moon are aligned just right during a Full Moon, so that the Sun casts the Earth’s shadow onto the surface of the Moon. On Wednesday, February 20, a total lunar eclipse will occur from 6:43 p.m. to 10:09 p.m. Mountain Time (adjust as needed for your time zone). Totality--when the Moon is entirely in the Earth’s shadow--will occur from 8:01 to 8:51 p.m. MT. The eclipse will be visible everywhere in the continental United States, and you can view it naked eye. Just watch the eastern horizon for the rising Full Moon, and then watch the shadow of the Earth creep across the Moon.

So what’s so valentine-ish about this, you ask? Well, during totality, the Moon will turn red! That’s right, red. It might be dull brick red or it might be scarlet, depending on atmospheric quality. The more dust and ‘gunk’ in Earth’s atmosphere, the redder the Moon will look. This blushing moonface occurs because some indirect light from the Sun still reaches the Moon’s surface, even though the Moon is in the Earth’s shadow. On its way to the Moon, this light first skims through Earth’s atmosphere, which filters out most of the blue. The remaining light, therefore, is red or orange.

Season’s greetings.