Geminids in the northern sky taken during the 2017 meteor shower.

Minnesota Skies: December 2018

Your local guide to observing celestial objects and events

Published11/27/2018 , by Parke Kunkle

The Geminid meteor shower in December often out classes its more famous cousin, the Perseids shower that occurs in August. Most of us miss it though for one good reason – it is cold outside. But this shower is the brightest shower of the year, with nearly 100 meteors per hour radiating from a spot near the bright star Castor. (See the Geminid radiant noted in the image below).

These meteor showers occur when Earth runs into swarms of tiny dust and gas bits that have been ejected or outgassed, usually from a comet. The Geminids come from an unusual object called 3200 Phaethon, more of a comet-asteroid combination.

Fun fact: Space rocks that are about to collide with Earth’s atmosphere are called meteoroids. Rocks that streak through the atmosphere are called meteors. Space rocks that reach the ground are called meteorites.

Best viewing occurs after midnight away from city lights. Dress in warm clothing, lie down in a lounge chair and watch with your naked eye. You can look in any direction but the streaks of meteors will appear to come from the constellation Gemini that shines high in the southeast around 1 am. In the case of the Geminids, you might see one meteor every few minutes with a small chance of seeing a brighter fireball. Be prepared to stay out for an hour or so to improve your chances of seeing several meteors.

To find Gemini in your Minnesota sky, look for Orion in the southwestern around 1 am. The twin stars of Castor and Pollux in Gemini in the southeast, Leo in the east and the Big Dipper standing on its handle in the northeast.

Sky & Telescope diagram of the Geminid meteor shower and nearby constellations.

The Geminid meteors can flash into view anywhere in the late-night sky. But if you follow their paths back far enough, they all appear to diverge from a point in the constellation Gemini. Credit: Sky & Telescope

Sky-lights

December Highlight Comments
2 Very bright Venus below thin crescent Moon 6 am, SE
3 Very bright Venus just below thin crescent with bright star Spica to the right 6 am, SE
4 Very bright Venus above right of very thin crescent Moon 6 am, E
13-14 Geminid meteor shower See notes above
14 Mars above Moon 6 pm, S
21 Faint Mercury less than 1 degree above left of bright Jupiter 7 pm, Low SE. Use binoculars
21 Winter solstice (northern hemisphere) Officially at 4:23 am CST

Resources

When viewing planets, stars or constellations in the night sky, it is helpful to use a sky map. Minnesota Starwatch is another great resource for tracking the night sky.

Meet up with other stargazing enthusiasts via Twin Cities Sidewalk Astronomers, MN Astronomical Society & MN Institute for Astrophysics.

 

Main image: 2017 Geminid Meteor Shower, taken in Inner mongolia, China. Credit: Yin Hao, NASA APOD