Tonight – December 8, 2014 – the big and bright waning gibbous moon shines directly in front of the constellation Gemini the Twins, the radiant point for the Geminid meteor shower. Our chart today shows the view in the east-northeast sky for about three hours after sunset. Gemini’s two brightest stars are Castor and Pollux. The star Castor nearly aligns with the radiant point of the Geminid meteor shower, which is going on right now and is expected to peak in activity on the nights of December 12-13 and, especially, December 13-14.
A bright moon can wash meteors from view. That’s why it’s fortunate that we’re still a few days away from the Geminid meteor shower’s peak. It’ll be at its best this coming weekend, featuring 50 or more meteors per hour in a dark sky. The waning gibbous and last quarter moon on the weekend won’t be nearly as obtrusive as tonight’s moon. Friday and Saturday evenings will present moon-free skies for meteor watching
That means, this weekend, you can start watching for Geminid meteors around 9 p.m. The Geminids fall most prolifically in the wee hours after midnight, centered around 2 a.m. local time. Although the moon will be up in the morning hours, the Gemind meteors are often bright and a good number of them can be expected to overcome the light of the moon.
This evening (December 8), the moon and Gemini will swing westward throughout the night, for the same reason the sun moves westward during the day. It’s because the Earth rotates eastward on its axis. All heavenly bodies – the sun, moon, planets and stars – appear to travel westward across the sky while the Earth appears to remain at rest. But we all know … it’s really the Earth that’s moving.
Moving westward through the night, the moon, and stars Castor and Pollux in Gemini, climb high overhead after midnight and swing into the western sky by dawn.
According to Greek sky lore, Castor and Pollux were twin brothers, born from Leda, their mortal mother, and sired by Zeus, the immortal god. Though the brothers were united in spirit, they were divided by circumstance. Castor, the mortal, was slain in battle, leaving his immortal brother inconsolable with grief. Pollux asked Zeus to release him from immortality, so he could join his brother in the great beyond.
Today, the Gemini Twins stand together in the heavens, a testament to the redemptive power of brotherly love.
Bottom line: Look for the moon near Gemini’s two bright stars starting about three hours after sunset on the night of December 8, 2014. Geminid meteors are now radiating from near this point in the sky. The shower will likely peak from late evening December 13 through dawn on December 14.