December’s full Moon is known by several names, including Cold Moon and Moon Before Yule. It’s also known as the Long-Night Moon because the Moon is in view for a longer time than any other full Moon of the year.
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Last Week's Stargazing Tips
December 11: Long-Night Moon
December 10: Moon and Aldebaran
Aldebaran, the eye of Taurus, the bull, stands close to the Moon at nightfall and even closer to the Moon in the wee hours of the morning. Blocking the bright Moon with your hand will help you discern the star’s orange color.
December 9: Sun Moves
As twilight fades away, the zodiac arcs high across the southern sky. It’s a trail of constellations with one thing in common: The Sun traverses their borders, so it passes through each of those constellations during the year.
December 8: Eridanus
Eridanus, the river, meanders through the southern evening sky. It is one of the largest constellations, stretching almost 60 degrees from north to south. Its northern end is near Rigel, the brightest star in Orion.
December 7: Pollux
Pollux, the brightest star of Gemini, rises in the east-northeast in mid-evening, below its “twin,” Castor. Pollux is almost twice as massive as the Sun. Although it’s only one-fifth of the Sun’s age, it’s already finished its “normal” lifetime.
December 6: 51 Pegasi
Under dark skies, the star 51 Pegasi is just visible to the unaided eye, high in the southwest at nightfall this month. It was the first Sun-like star with a confirmed planet. The planet’s discoverers earned this year’s Nobel Prize in Physis.
December 5: Betelgeuse
Betelgeuse, the bright orange star that marks the shoulder of Orion, the hunter, is in the east on December evenings. The supergiant star is at least 300 times wider than the Sun and 20 times more massive, and emits 100,000 times as much energy.