The Night After Christmas Sky Show – NASA Science
On Dec. 26th, the night after Christmas, Venus and the slender crescent Moon will gather for a jaw-dropping conjunction in the western sky.
A Venus-Moon conjunction photographed in Nov. 2011 by Thad V’Soske of Fruita, CO. The "Night After Christmas" conjunction will look about the same. Copyright: T. V’Soske/Cosmotions.com
The action begins shortly before sunset. Around 4:30 pm to 5:00 pm local time, just as the sky is assuming its evening hue, Venus will pop into view, glistening bright in the deepening twilight. No more than 6 degrees to the right lies the crescent Moon, exquisitely slender, grinning like the Cheshire cat with his head cocked at humorous attention. This is a wonderful time to look; there are very few sights in the heavens as splendid as Venus and the Moon gathered close and surrounded by twilight blue.
But don’t go inside yet, because the view is about to improve. As the sky fades to black, a ghostly image of the full Moon materializes within the horns of the lunar crescent. This is caused by Earthshine, a delicate veil of sunlight reflected from our own blue planet onto the dusty-dark lunar terrain. Also known as "the Da Vinci glow," after Leonardo da Vinci who first understood it 500 years ago, Earthshine pushes the beauty of the conjunction over the top.