In December, it’s tempting to stay inside and avoid the cold night air. But the December night sky is impressive! Find a star chart or planetarium App, then go out on a clear night, at least briefly, to enjoy the spectacle! On evenings from December 8 to 14 at about 9 PM, moonlight is absent, allowing us to see with eyes unaided, Jupiter, Saturn, star clouds of our Milky Way Galaxy, the striking stars of winter, and a distant galaxy, far beyond our own. That very bright object high in the south is the planet Jupiter, and Saturn is low in the southwest. Star clouds of the Milky Way extend from Constellation Cygnus in the west northwest, up through Cassiopeia and Perseus, near the zenith, to Constellations Auriga and Gemini in the east. The great Square of Pegasus, an autumn asterism, is high in the west. Constellation Andromeda extends eastward across the zenith from the Great Square’s northeastern-most star, Alpheratz. Use a star chart or App to find M31, the Andromeda Galaxy, which is nearly overhead during the early evening. At 2.5 million light years away, each light year corresponding to 6 trillion miles, the Andromeda Galaxy is the most distant thing we can see with our eyes unaided.
Look to the east, where the stars of winter are rising. Do these stars seem unusually bright? That’s because they are bright! Many of the sky’s brightest stars shine during our winter nights, including reddish Betelgeuse and blue-white Rigel in Orion, Procyon the “little dog star”, and Sirius, the sky’s brightest star, located southeast of Orion near the horizon. North of Orion, look for yellow-white Pollux and blue-white Castor in Constellation Gemini. And spot bright, yellowish Capella and reddish Aldebaran, shining high in the east.
If it’s clear on the night December 13-14, watch for Geminid Meteors, as debris from the asteroid or “rock comet”, Phaethon, enters our atmosphere at 80,000 miles per hour. Try to brave the cold, at least for a while, because the Geminids are the strongest and most reliable of the annular meteor showers. You may spot meteors all over the sky, possibly as many as 120 per hour after midnight. Lesser numbers of Geminids may be seen for a few nights before and after the night of December 13 to 14.
Although December nights can be cold, gaze upward, at least briefly, into the Western Slope’s dark skies! There’s a lot to enjoy!
You’ve been listening to “Western Slope Skies”, produced by the Black Canyon Astronomical Society and KVNF Community Radio. I’m Art Trevena.
Weblinks:
https://www.popastro.com/main_spa1/andromeda-finder-charts/
https://science.nasa.gov/solar-system/meteors-meteorites/geminids/
