Weather Talk: Annual Perseid meteor shower is always a good show
For even the most amateur of astronomers, this week's annual Perseid meteor shower is one of the most popular sky shows around. During the first and second week of every August, Earth's orbit takes us through the path of Comet Swift-Tuttle, which has left a dirty path of dust particles and small rocks.
This weekend, Earth will pass through the dirtiest middle part of the path where any of those rocks and specks that get caught in our outer atmosphere will quickly incinerate, creating shooting stars and a few of the brighter, more spectacular fireballs. Shooting stars are not stars at all, but tiny rocks. Fireballs are somewhat bigger rocks.
The combined velocities of the meteors, the Earth in its orbit, and the Earth's rotation result in a relative speed ranging from 25,000 to 160,000 mph. Therefore, virtually all meteors burn up in the friction of the outer atmosphere, where they give a brief but beautiful light.