2011 Geminids Shower

The annual Geminid meteor shower occurs when debris from the asteroid 3200 Phaethon intercepts the Earth. This is an unusual type of shower in having an asteroidal, rather than cometary parent. However, evidence suggests that Phaethon is actually the rocky core of an evaporated comet. These meteors intercept the Earth at a fairly low speed of 35 km/s (79,000 mph). Because of this, Geminids tend to be slow and colorful- probably the prettiest of the major showers.

This is a composite image of 166 Geminid meteors collected between sunset on December 12 and sunrise on December 16 (14, 20, 90, and 42 meteors respectively). Since the images were collected over many hours, the radiant of the shower is not in a fixed location. Conditions this year were generally poor, with a light snowfall on the peak evening of December 13/14 and a waning gibbous Moon interfering (this shower occurred just a few days after the December 10 total lunar eclipse.) The Moon has been digitally removed from this composite.

Long necklace-like trails on the image are the paths of stars and planets, circling the north celestial pole in the upper left.

This image contains only meteors identified as Geminids. Several other showers are currently active as well, including the Puppid-Velids, Monocerotids, Chi Orionids, and Sigma Hydrids.

Shower Meteor Frequency

This graph plots the distribution of meteors over four evenings. The hourly rate represents a simple raw count of events, and hasn't been corrected for zenith angle or magnitude. Scale the values shown by approximately three times to get the equivalent visual zenithal hourly rate. The first evening was partly cloudy and the second was snowy after midnight, so counts for those dates are understated.