The highlight of the winter sky in the Northern Hemisphere is the figure of a man, wearing a belt, with a red giant named Betelgeuse perched on one shoulder and another called Bellatrix on the other shoulder. It's Orion, the Hunter, perhaps the most widely recognized constellation in the sky.
It takes little imagination to see a man in this pattern of stars. A rather empty area marks his head, two bright stars his shoulders, three in a row his belt and waist, and two more his knees. A line of fainter stars below the belt traces his sword. A curve of stars on one side is his shield, raised to ward off an attack by Taurus, the Bull, to the west. The other arm is usually said to wield a club.
Many myths exist concerning this star group. To the ancient Arabs it was known as Al Jauzah or Al Jabbar, the Giant. In India it was Prajapati, lord of the creatures and father of twenty-seven daughters. To the Egyptians these stars were the resting place of the soul of Osiris, god of the underworld and a symbol of creativity and the continuity of life.
In Greco-Roman mythology Orion was a famed but boastful hunter, who went so far as to claim that no beast could kill him. To teach Orion a lesson, the spiteful goddess Hera (or Juno) sent a tiny scorpion to sting him. Orion smashed the scorpion with his club but not before it had stung him fatally. Orion and the scorpion, the constellation Scorpius, were placed on opposite sides of the sky. When one rises, the other sets, and these two enemies never appear in the sky at the same time.
Planets of the Week
Saturn and Jupiter are found in the constellation Taurus, the Bull, and can be seen until the early morning hours. Jupiter is large and bright, and one of the first "stars" visible when darkness falls. (The September 18 and September 25 Sky Guides provide more information on viewing our solar system's largest planets and the array of moons that surround them. Click here to read the former; click here to read the latter.)
Venus is setting more than three hours after sunset. Look in the southwestern sky after the sun goes down to spot the brilliant Evening Star, getting larger and brighter with each passing night this month. Sharp-eyed observers can even spot Venus in daylight. Mars is visible in the very early morning hours, traveling from the constellation Virgo to Libra. Watch for it to brighten steadily throughout the first half of the year.
Mercury, always difficult to see because of its proximity to the sun, makes a brief evening appearance this week. The best date to look for it is January 28, when it remains in the western sky, just above the horizon, for about an hour and a half after sunset.
At 9 p.m. on January evenings the last of the late-summer and fall constellations are just about to set. Deneb, the bright alpha star in the constellation Cygnus, is just above the northwestern horizon. The Great Square of Pegasus is almost due west, and the constellations Cepheus, Cassiopeia, Perseus, and Andromeda, somewhat higher, can still be seen. Ursa Minor, also known as the Little Bear or the Little Dipper, hangs almost straight down from Polaris, the North Star.
Leo, the Lion, and its bright alpha star, Regulus, are just rising in the east-northeast. Between Leo and Gemini lies the faint zodiacal constellation Cancer, the Crab. To the north is Ursa Major, the Great Bear. The Big Dipper, a part of that large constellation, stands upright on its handle.
The southeastern quadrant of the sky holds Orion, the Hunter, one of the brightest and most easily recognized constellations. Orion also serves as a pointer to several other constellations. The three equally bright, evenly spaced stars of Orion's belt point roughly toward Aldebaran, the alpha star in Taurus, to Orion's west, and toward Sirius, the alpha star in Canis Major, to the southeast. Sirius, also called the Dog Star, is the brightest star in the sky. Above Orion's belt are the stars of his shoulders: the brighter, eastern star of the two is the red star Betelgeuse; the other is called Bellatrix. Below the belt are two stars marking his knees: the brighter, western one is the bluish-white star Rigel; the other is Saiph.
A line drawn from Rigel through Orion's belt to Betelgeuse and then extended northward points just north of Gemini, the Twins, and that constellation's two brightest stars, Castor and Pollux. Between Gemini and Canis Major lies the bright star Procyon, the alpha star in Canis Minor, the Little Dog.
There are few bright stars in the southwestern quadrant of the sky. The dim but large constellations of Pisces (the Fish), Cetus (the Sea Monster), and Eridanus (the River) span most of the western and southwestern sky. Near the meridian high in the south is Taurus, the Bull. The bright orange star Aldebaran marks his eye and the V-shaped star cluster the Hyades marks his face. High in the southwest is the lovely star cluster known as the Pleiades, or the Seven Sisters. Almost overhead is Capella, the bright star in Auriga, the Charioteer.