Geminid Meteor Shower

The Geminid Meteor Shower is coming up! We should have a good chance to see some meteors this coming Saturday night, December 13. So what is a meteor shower, anyway? If you would like a review, read this post. Basically, meteors are little bits of dust entering Earth's atmosphere and causing the air in front of them to compress and glow. 

2013 Geminid meteor shower by Asim Patel. Image credit: Wikimedia Commons

How to watch the Geminid Meteor Shower 
If you are interested in watching the Geminid Meteor shower, the first step is to find a safe, dark viewing spot. You will want to get out of city lights, and dress warmly. Meteors may be visible as soon as the sky is dark, but peak viewing will be around 2 AM local time. The Moon will be relatively bright and will block the light of some of the meteors, but if you face away from the Moon you should be able to see the bright ones. 

The Geminids will originate from the area of the sky where the Gemini constellation is located. Image Credit: Stellarium

The Geminids are so named because they appear to originate from the part of the sky marked by the Gemini constellation (see image above). I usually find Gemini by finding Orion first, and following the line marked by his blue foot, through his belt, through his red shoulder, up to the heads of the Gemini Twins, Castor and Pollux. The meteors will appear all across the sky, but if you traced their paths backwords, they would all point towards the  Gemini Twins. Just lay back and look up, and you will see them all over!

Frederic Edwin Church's depiction of a meteor, entitled The Meteor of 1860. Image Credit: Wikipedia Commons

Predictable meteor showers happen when the Earth passes through the dust trail left behind by a comet. The Geminids have an unusual origin, however. They are the result of a debris trail left behind by a unique asteroid, 3200 Phaethon. Phaethon has a comet-like orbit that brings it closer to the Sun than any other known asteroid, about half the distance from the Sun to Mercury (0.14 AU). Even though Phaethon's orbit is comet-like, it is classified as an asteroid because it is composed of dark, mostly rocky, material. Comets are mixtures of rock and ice. The Earth will be passing through Phaethon's dust trail this week, causing the meteor shower.

3200 Phaethon's orbit around the Sun. Image Credit: Wikipedia Commons

Good luck watching the Geminid meteor shower this weekend! I hope you stay warm and catch some nice fireballs. And if you don't want to stay up for hours in the cold, just scan the sky for a little bit after dark. You will probably catch one or two!
By the way, in case you missed it, NASA's Orion spacecraft, designed to take human explorers beyond low Earth orbit, successfully completed an uncrewed test flight last week! Check out lots of great photos here. And as always, learn more about space and science at the Peoria Riverfront Museum's Dome Planetarium. 

Earth, from the Orion spacecraft's test flight. Image Credit: NASA