The strongest and most reliable meteor showers are the Perseids of August and December's Geminids. Balmy weather and summer vacations have made the Perseids well known and popular, but the Geminids are actually easier to view from mid-northern latitudes. For one thing, nights are much longer in December. And while the Perseids are best viewed just before dawn (as most showers are), you can easily get an eyeful of the Geminids during the evening hours.This year the Moon will be nearly new when the Geminids peak on the night of December 13-14. The shower's radiant, the point in the sky from which they all seem to originate, is near Castor and Pollux. It's well up in the east by 9 or 10 p.m. and crosses near the zenith (for mid-northern observers) around 2 a.m.
The shower should peak around 5:00 Universal Time on the morning of the 14th, corresponding to midnight EST and on the 13th at 9 p.m. PST — excellent timing for North America and Western Europe. Under dark-sky conditions you might see as many as 120 medium-speed meteors per hour. (Light pollution reduces the numbers.) The shower is active to a lesser extent for at least a day or two beforehand and about one day after.
The Geminid meteor shower is extremely unusual in that its parent object isn't a comet. Instead, it's an asteroid, a chunk of rock roughly 3 miles across called Phaethon (pronounced FAY-uh-ton). How can an asteroid produce meteoroids? Nobody knows for sure. Many scientists believe that Phaethon is the core of a comet that's been baked completely dry. Maybe a smaller asteroid collided with it long ago. In any case, a ribbon of debris lines Phaethon's orbit.Meteor watching couldn't be easier. Lie back in a reclining lawn chair, relax, and watch the sky overhead. Ideally, you want nothing but sky in your field of view — not trees, and certainly not the ground. That means that you should either lie flat on your back or recline so that you face at least 45° above the horizon. Also remember that December nights are cold at mid-northern latitudes. Normal winter clothing won't even come close to keeping you warm after you've been lying still for a couple of hours. The best solution is to use a sleeping bag. Second best is plenty of blankets over your warmest clothing. And don't forget a hat and gloves!
The arriving Geminids will cover the whole sky, so it doesn't really matter which way you're pointed. If you look straight at the radiant, you'll see meteors coming directly toward you, bright but with short trails. Look the opposite way, and you'll see lots of long meteors moving away from you.
Careful counts of meteors have scientific value. Click here to learn how to conduct a scientific meteor count and how to report your results to the International Meteor Organization.
Update: It was indeed a great year for the Geminids! The shower peaked at about 150 meteors per hour (the Zenithal Hourly Rate: the rate as would be seen under ideal conditions) during the late hours of December 13th Universal Time, according to this preliminary activity profile posted in near-real time by the International Meteor Organization.