by Geoff Chester, USNO Public Affairs | 11 January 2022 Messier 42, the Great Nebula in Orion, imaged 2021 December 27 from Ocean City, Maryland with an Antares Sentinel 80mm (3-inch) f/6 refractor, iOptron Cube Pro alt-az mount, and a Canon EOS Rebel SL2 DSLR. The Moon waxes as she arcs through the stars of the Great Winter Circle this week, brightening the long chilly winter nights. Full Moon occurs on the 17th at 6:48 pm Eastern Standard Time. January’s Full Moon is popularly known as the Wolf Moon, a name that derives from old European accounts of wolves howling through the long nights. Other names include the Ice Moon and Moon after Yule. Look for the Moon to the south of the Pleiades star cluster on the evening of the 12th. She passes between the “horns” of Taurus, the Bull, on the evening of the 14th before moving through the stars of Gemini to close out the week. January is the month that features the stars of the Winter Circle as the showcase for nighttime viewing. Somehow the colder air seems to accentuate the stars’ varied colors. Despite the strengthening light of the waxing Moon, the collection of bright stars in this part of the sky seems to stand out more clearly than at other times of the year. I have often marveled at how the stars of winter seem to add a sense of warmth on nights with frigid temperatures while brightening the darkness of the lengthy nights. Ten of the thirty brightest stars in the entire sky lie within the confines of the Winter Circle asterism. I still remember the cold January night when, as a child, I first “discovered” the three “Belt Stars” of Orion. Although they were not the constellation’s brightest members, their near-perfect spacing and striking blue colors made them easy to spot night after night. I soon learned to recognize the other constellations in the vicinity, but Orion always stood out. After my first telescope arrived under the Christmas tree, I spent many cold January nights looking at each of the Hunter’s stars before stumbling on the group known as “The Sword”. Amid the field of blue stellar beacons was a small knot of stars surrounded by a soft, fuzzy glow. I had “discovered” the Great Orion Nebula. Over the years I learned more about Orion’s stars as well as his wonderful non-stellar objects like the Great Nebula. Even today I spend more time observing Orion than just about any other constellation. Orion offers observers of any skill level a host of objects to delight the eye. Even without a telescope, the contrast between the ruddy hue of the star Betelgeuse with the ice-blue tint of Rigel is striking. Binoculars enhance this contrast and bring out the deeper blue tints of the Belt Stars. Looking under the belt stars will reveal the gaggle of stars of the Sword, and in the middle you will see the brighter parts of the Great Nebula. The small fuzzy patch that you see in binoculars becomes exquisitely detailed as you employ telescopes of larger apertures. Even under bright suburban or moonlit skies the nebula becomes almost three dimensional, its brightly glowing core surrounded by dark whorls of opaque dust and gas. In its center you will find a tight knot of four stars known as the Trapezium, and these stars are some of the youngest known in the galaxy. The Great Nebula is a true stellar nursery, and almost all of Orion’s blue stars originated there. It remains my favorite “deep sky” object in the sky. The bright planets have now retreated to the early evening and pre-dawn sky. As evening twilight falls, look to the southwest for bright Jupiter, which should be easy to spot about 20 minutes after sunset. By 6:00 pm, if you trace a line from Jupiter to the sunset point on the horizon, you should be able to see the paler glow of Saturn about ten degrees above the horizon. If you scan between Saturn and the horizon, you should be able to spot the somewhat brighter glow of the elusive planet Mercury, which will seem to hang in this part of the sky before beginning a precipitous drop toward the Sun by the end of the week. If you’re up before dawn look to the southeastern sky as morning twilight begins to brighten the horizon. You will find the stars of Scorpius becoming prominent, led by the bright red-hued Antares. Thirteen degrees to the east of the star is another ruddy object, the planet Mars. Over the course of the week the red planet will about five degrees further eastward from the star. As twilight becomes brighter, keep an eye on the southeast horizon for the bright glow of Venus. By 7:00 am she crests the horizon, and by the end of the week you should be able to see her more easily as she climbs away from the Sun’s glare.