This week is the time of the annual Leonid meteor shower. The peak for 2012 Leonid will be tonight, November 17 at 3 a.m. EST. It was will be more visible because of the moonless weekend sky because the moon will have set by that time, so the reduced night won’t wash out any Leonids you may see.

The Leonids are associated with the periodic comet Tempel-Tuttle, first discovered in 1865. This comet has a period of 33.2 years, so it was last close to the sun in 1998 and it will return in 2031. After Tempel-Tuttle’s discovery, it was traced back to a comet observed in 1366.

When astronomers realized that Tempel-Tuttle’s last close approach to the sun was in 1833 and that it coincided with one a huge meteor storm, they began to realize that meteors had their origins in comets.