Sky watch: Orion constellation hunting after all these years

During early February, one of the most remarkable star groupings of all the heavens shines in the southeastern sky. For countless centuries, the star grouping known as Orion, the hunter, has graced the night sky at this time of year.

This ancient constellation was known to the Sumerians of Mesopotamia as far back as the 4th millennium B.C.E. 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 time machine, we can step outdoors and find him still standing guard just above the southeastern horizon 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 midsection appear three equally bright stars - Alnitak, Alnilam and Mintaka - that trace a straight line outlining the hunter's belt.

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. Try imagining him as an hourglass, a bow tie or even a butterfly.

Hanging south of the hunter's "belt" appears his sword in the form of several faint stars, one of which appears hazy. This is known to astronomers as M42 or the Great Orion Nebula.

Modern astronomers know M42 as one of the most prolific star-forming 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 all the heavens.

M42 is a colossal cloud of interstellar gas and dust that lies about 9 thousand trillion miles, or 1,500 light years, away and is lit from within by the light of brilliant young stars. It is 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.