||2004 Leonid Shower|
The annual Leonid meteor shower occurs when debris from Comet Tempel-Tuttle intercepts the Earth at a very high velocity. This debris lies in a collection of narrow streams produced by different passes of the comet. These streams are pretty well understood, which has led to growing accuracy in predicting Leonid shower performance. For the last several years, Earth has passed through dense, narrow streams which have produced spectacular showers and meteor storms (2001, 2002). We have now entered a long period of "normal" Leonid activity, on the order of 40 meteors per hour at the maximum.
This is a composite image of 32 meteors collected on the morning of November 19, between 1:29 and 6:06 MST (UT 8:29 to 13:06). Because the images were collected over many hours, the radiant of the shower is spread out. However, the approximate radiant is fairly clear, since most of the meteors in this image occurred over a two hour period. 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. Five of the meteors qualify as fireballs, including one very impressive event that left a distinct trail bright enough for the camera to record (video, 51 KB).
graph plots the distribution of meteors over the evening, and clearly shows
an increase in activity as the radiant rises higher in the sky.