Thursday, December 24
• Full Moon tonight (exact at 6:11 a.m. Christmas morning EST). The full Moon nearest the winter solstice rides higher across the night sky than any other full Moon of the year. It's highest of all around midnight, "giving luster of midday to objects below." (Moreover, tonight's full Moon is closer to perigee than average.) The Moon will be shining north of Orion's main pattern, near the top of Orion's dim club.
Friday, December 25
• Merry Sol Invictus! In late Roman times this date was celebrated as Dies Natalis Solis Invicti, the Birthday of the Unconquered Sun — when the Sun began to recover from its long decline with the hopeful promise, in the cold and the dark, of a new spring and summer to come.
• This evening the Christmas Moon, just a day past full, hangs in the east in Gemini. Look for Castor and Pollux, the heads of the Twins, to its left. Very high above Castor and Pollux shines the constellation Auriga, with bright Capella.