David Murr

Get Ready for the 2013 Geminid Meteor Shower!

You know the old saying “we saved the best for last”? The end-of-year Geminid meteor shower could certainly be considered one of the best. Along with the summertime Perseids, the Geminids tend to feature the most meteors. Last December’s shower was impressive — as I noted at the time, it was easily one of the best I’ve seen in recent memory.

This year, the Geminid meteor shower peaks on Friday, December 13 and Saturday, December 14. Unfortunately, the shower will be sharing the sky with the Moon much of the night, making fainter meteors harder to see. But with an estimated 120 meteors per hour visible under ideal conditions, and a typically high number of fireballs, it’s still well worth heading out.

What Is a Meteor, Anyway?

A meteor is a small piece of dust from space that enters the Earth’s atmosphere. Although these particles are usually tiny — most fall somewhere between the size of a grain of sand to a small pebble — they collide with the air that blankets our planet at incredible speed, causing them to burn up high above our heads. It’s this spectacular disintegration that we see as a so-called “shooting star.”

Although sporadic meteors can be seen here-and-there on practically any night from an area with reasonably dark skies, meteor showers occur when the Earth’s orbit crosses paths with a concentrated stream of cosmic dust. Most of this debris is left over from comets; the Geminids are unique though, as it’s one of the few showers that originates from dust from an asteroid (in this case, one called “3200 Phaethon“). That’s unusual because asteroids typically don’t have dusty tails that follow them around.

What Do I Need to Watch a Meteor Shower?

Very little, actually!

One fairly common misconception is that you need a telescope to watch for meteors. The truth is, you already have everything you need to enjoy the show: your eyes! Binoculars and telescopes are great for getting a detailed look at objects that appear to move slowly across the sky, like the Moon, planets, stars, and nebulae. But meteors are usually visible for only a fraction of a second and quickly move across a relatively large swath of sky, so using a telescope will actually make one harder to spot.

Aside from your own eyeballs, you’ll want to have a few other things.

After arriving at your observing site, give your eyes at least 15–30 minutes to adjust to the darkness so you can be sure to see fainter meteors.

Where and When Do I Look for Meteors During the Geminids?

The not-so-helpful answer is: everywhere! Meteors can appear anywhere in the sky, but they will all appear to originate from a point in the sky called the radiant. The reason this particular shower is called the “Geminids” is because the meteors appear, from our vantage point here on Earth, to radiate from the constellation Gemini. So you may want to locate Gemini first and scan the skies in that direction. But remember, you’re likely to see meteors even on the other side of the sky — they’ll just appear to be “coming” from the direction of Gemini. On the morning of December 13, the easiest way to find Gemini will be to look for Jupiter, which will be the brightest object in the western sky, just above the easily-recognizable Orion.

Although the Geminids will be visible practically all night during the peak, the best time to watch this particular shower is probably during the early morning hours, after the moon sets, on December 13 and 14. On December 13, that’s about 4 AM. The next morning, it’s about 4:45 AM. Heading out around 3–3:30 on either morning is a good bet. The twilight of dawn won’t begin to encroach until about 6 AM.