The Leonids is an average shower, producing an average of up to 15 meteors per hour at its peak. This shower is unique in that it has a cyclonic peak about every 33 years where hundreds of meteors per hour can be seen. That last of these occurred in 2001. The Leonids is produced by dust grains left behind by comet Tempel-Tuttle, which was discovered in 1865. The comet makes its way around the sun every 33.3 years, leaving a trail of dust rubble in its wake. When Earth’s orbit crosses this trail of debris, pieces of the comet fall toward the planet’s surface. Drag, or air resistance, in Earth’s atmosphere causes the comet’s crumbs to heat up and ignite into burning balls of fire called meteors. Sometimes, meteors fall at rates as high as 50,000 per hour.
The shower runs annually from November 6-30. It peaks this year on the night of the 17th and morning of the 18th.
The second quarter moon will block many of the fainter meteors this year. But the Leonids can be unpredictable so there is still potential for a good show. Best viewing will be from a dark location after midnight. Meteors will radiate from the constellation Leo, but can appear anywhere in the sky.
Irene W. Pennington Planetarium 