2004 Geminids Shower

The annual Geminid meteor shower occurs when debris from the asteroid 3200 Phaethon intercepts the Earth. This is a very rare type of shower in having an asteroidal, rather than cometary parent.

The shower produces fairly long, bright, moderate speed meteors. This year's shower was particularly fine, occurring during a new Moon.

This is a composite image of 144 meteors collected on the evening of December 13/14, between 18:32 and 6:24 MST (UT 1:32 to 13:24). Because the images were collected over many hours, the radiant of the shower is spread out. Long necklace-like streaks are stars or planets captured as they traveled across the sky over many hours. These form arcs centered on Polaris, which is located fairly low in the sky above the zero degree azimuth marker. The track near the top between 300° and 315° was made by the International Space Station, which passed over Cloudbait Observatory at 6:08 MST. The long, bright fireball on the left occurred at 6:15 MST, and can be viewed below.

The next night (December 14, 18:33 MST) I caught an impressive earth-grazer that covered half the sky. It was about five seconds in duration, which exceeded the capture buffer. As a result, it was seen as three separate events, which is why it is shown as three close events.

Shower Meteor Frequency

This graph plots the distribution of meteors over the evening of the 13/14. The data suggests a double peak, but this may be an artifact caused by a brief period of increased cloud cover at about 6:30. At 5:30 I observed a visual rate of 150/hour.