Stargazers: Finding the great celestial hunter
During early February, one of the most remarkable star groupings of all the heavens shines high in the southeastern sky. For countless centuries, the star grouping known as Orion has graced the night sky at this time of year.
This ancient constellation was known to the Sumerians of Mesopotamia as far back as 4,000 B.C. Later, the Egyptians saw Orion as the god Osiris, and the early Greeks knew him as the son of the sea god Poseidon and a powerful hunter.
Today, as if entering a magical time machine, we can step outdoors and find him still standing guard in the southeastern sky after dark. You won't have trouble identifying him either, since Orion is one of the few constellations that actually resembles its namesake.
Its two uppermost stars — Betelgeuse and Bellatrix — mark the shoulders of the celestial giant, and Saiph and Rigel form his knees. Across his mid-section appear three equally bright stars — Alnitak, Alnilam and Mintaka — that trace a straight line outlining the hunter's belt.
But that's not all. Fainter stars mark his outstretched arms holding a shield and a club, while a sword hangs from his belt; and in place of his head lies a very faint star named Meissa, suggesting that Orion may be more brawn than brains.
Of course one of the great things about stargazing is that, if you can't trace the image of a hunter among Orion's stars, you're free to make up any other shape you like. For example, try imagining him as an hourglass, a bow tie, or even a butterfly.
Orion is one of those star groupings that happens to lie directly over the Earth's equator and, unlike most constellations, at least part of it can be seen from every location on Earth. In other words, no matter where in the world you live or travel at this time of year, Orion will always be a welcome and familiar companion in your sky.
While the constellation itself is full of amazing sights, it is in the hunter's sword that we find one of the most outstanding. It appears to the unaided eye as a smudge of light just below the three belt stars of the hunter.
Modern astronomers know this region as M42 or, more poetically, the Great Orion Nebula; it is one of the most prolific star-birthing regions in our entire Milky Way Galaxy — a stellar nursery — where new stars and planetary systems are continually being born. Binoculars show it as a brighter and larger haze surrounding some bright stars, but aim a small telescope in its direction and you will experience one of the most marvelous sights in the entire sky.
M42 is a colossal cloud of interstellar gas and dust that lies about eight thousand trillion miles, or 1,300 light years, away, and is lit from within by the light of brilliant young stars. It is, without question, one of the largest, brightest and most beautiful of all "deep sky" objects.
If you miss seeing the great hunter and its nebula this week, don't worry; you've got plenty of time. Its stars will grace our evening skies well into springtime.