Jimmy Westlake's Celestial News column appears monthly in the Steamboat Today.
Find more columns by Westlake here.
Have you ever seen a centaur? May is centaur season and, if you know right where to look, you can spot one this month.
Centaurs, half-man, half-horse beasts, figured heavily in the mythology of the ancient Greeks. It is possible that the legend of the centaur began when someone long ago first saw humans on horseback and imagined them to be some sort of human-equine hybrid.
One of our most ancient constellations represents just such a creature, the constellation of Centaurus. This celestial centaur was first mentioned in Greek literature from the fourth century B.C. and is thought to represent a centaur named Chiron. Most of the centaurs were considered to be barbaric, uncouth beasts, but Chiron was an exception. He was a wise old centaur who served as the personal tutor of many Greek heroes, such as Hercules, Theseus and Jason. During one of Hercules' many scuffles, Chiron was accidentally nicked by one of Hercules' poisoned arrows. Being immortal, Chiron could not die, but the agony of the wound was so severe, that he begged Zeus to revoke his immortality. This he did, and Chiron was mercifully allowed to die. Zeus then immortalized the image of Chiron among the stars as our constellation of Centaurus.
Two thousand years ago, the constellation of Centaurus could be seen in its entirety from mid-northern latitudes, but the perpetual wobbling of the Earth on its axis has since carried the image of the centaur far to our south such that we can only see his human half from Colorado. His horse half remains hidden from our view, below the southern horizon. Every spring, he briefly pops his head up above our southern mountains and looks in on us.
You can see Centaurus, too, peeking in on us. Go outside about 10 p.m. in late May and look south, underneath the bright blue star Spica. There you'll spot the centaur's triangular head, his arms and human torso, but his equine half remains hidden from view. To see it, you would need to travel south along the curvature of the Earth to the latitude of the tropics.
Here's what we don't see because it's hidden behind the Earth: The front hooves of the centaur are two of the sky's brightest stars, Rigel Kentaurus and Hadar. Rigel Kentaurus is better known by its other name, Alpha Centauri. At a distance of only four light years, the triple star system of Alpha Centauri is the closest star system to our own.
But that's not all that's hidden just beyond our view. Tucked in under the belly of the centaur are the four stars of Crux, the Southern Cross. Although it's the smallest of the 88 constellations, Crux's reputation has reached legendary status. The stars of Crux originally represented the back hooves of Centaurus, but as the Earth's precession carried them out of the view of Europeans, over the centuries they were forgotten. European explorers rediscovered them and renamed them in the 16th century as they sailed the southern seas and marveled at the Southern Cross.
Professor Jimmy Westlake teaches astronomy and physics at Colorado Mountain College's Alpine Campus. He is an avid astronomer whose photographs and articles have been published all around the world. His "Celestial News" column appears weekly in the Steamboat Pilot & Today and his "Cosmic Moment" radio spots can be heard on local radio station KFMU. Also, check out Jimmy's astrophotography Web site at www.jwestlake.com.