It is time for the annual mid-November Leonid meteor shower which peaks before dawn (2-6am) as the Earth passes through the debris left behind by the comet Tempel-Tuttle. This comet, like all others, is slowly disintegrating and over the centuries its remains have spread all along its orbit to form a moving river of rubble millions of miles wide and hundreds of millions of miles long. This year has the advantage of a lunar phase (1st quarter) that should not interfere with sky gazers in the late night time period; however, it is not expected that the show will be nearly as good as it was from 1998 to 2002 when the comet was in closer proximity to the Earth. The rate of meteors during those great viewing years of 1998 to 2002 ranged from a few hundred to a few thousand per hour whereas the expectation for tonight’s show is on the order of around 10-15 meteors per hour. The particles are traveling at 45 miles per second with respect to the Earth and when one of them strikes the Earth’s upper atmosphere about 50 to 80 miles up, friction vaporizes it into a quick, white-hot streak. The vast majority of Leonids are not strong enough to survive the atmospheric flight and as such they cannot reach the Earth’s surface. The meteors will appear as if they are originating from the constellation Leo (hence the name) - to find Leo look to the eastern sky and then look up. As far as viewing conditions are concerned, they look excellent in the Mid-Atlantic region for the pre-dawn hours with mostly clear skies expected, but it'll be downright cold.
One other note, there actually will be a 2nd chance at viewing this meteor shower during the early morning hours of Tuesday, the 20th, when it peaks for a second time. A second peak is somewhat unusual, but is possible as the Earth passes through a second debris shield left by the comet. In fact, the second peak may produce a slightly higher number of meteors per hour in the pre-dawn hours of next Tuesday.