2004 Perseids Shower

The annual Perseid meteor shower occurs when debris from Comet Swift-Tuttle intercepts the Earth at a high velocity. This debris is somewhat diffuse, so we see activity for many days on either side of the peak. The Cloudbait allsky camera recorded two or three bright Perseids per hour every night for a week before the shower maximum.

This is a composite image of 133 meteors collected on the evening of August 11/12. Since the images were collected over about eight hours, the radiant of the shower is not in a fixed location. However, because most of the meteors occurred between 4am and dawn (UT 11:00 to 12:45), there is still the sense of a common radiant. I didn't analyze every meteor in this image; it is likely that five to ten of these meteors are sporadic events unrelated to the Perseid shower.

Long string-like images are stars or planets captured as they traveled across the sky over many hours. Venus and the Moon are seen rising next to each other at the left.

Shower Meteor Frequency

This graph plots the distribution of meteors over the evening, and clearly shows a large increase in activity shortly before dawn (when the radiant is directly overhead).