The Leonid meteor shower will peak tonight at 11pm. This year will provide clear, favorable conditions for viewing the powerhouse Leonid meteor shower show. The moon is only the first quarter phase, and will have long set in the West by the time the constellation Leo, for which the Leonids are named after, climbs high in the sky to provide the best atmospheric viewing conditions.
The Leonids are the remains of the Tempel-Tuttle comet. The Earth annually passes through its dusty debris trail, which contains debris as tiny as a grain of sand, and creates an incredible light show for patient observers.
Occasionally, we pass through an unusually thick concentration of debris, and in 1999, 2000, and 2001, observers were graced with meteor showers showing more than one thousand objects per hour. The comet had passed through the inner solar system near these times, creating a much higher than expected concentration. The comet has long since vacated our region of the solar system, and these areas of high concentration are expected to be gone, creating a much more modest estimate of what to expect this year.
These bits of "debris" are actually coined meteoroids, the proper term for debris before entering Earth's atmosphere. Meteors are meteoroids that have entered the atmopshere and "lit up". Leonids never hit the ground due their brittle composition, but if one did, which is literally nearly impossible, it would be called a meteorite.
Leonids turn up the heat, literally and figuratively. The meteors can heat up to over 3000 degrees Farenheit. They also have been clocked travelling more than 80mps (that's miles per second, kids) through the atmosphere until they eventually burn up about 60 miles above us.
Leonids were once thought to be the heralds of the end of the world. Thank goodness we know different. We can just enjoy their annual wonder.