When the Leonid meteor shower erupts tomorrow, sky-watchers on Earth have little to fear. They are so insubstantial that they disintegrate almost immediately when they hit Earth's atmosphere. The result is a shooting star. Earth-orbiting satellites might have more to worry about.
Tiny meteoroids can poke holes in solar panels, pit surfaces, and short out electronics.
The hazard from the Leonids is greater than the danger from most meteor showers for two reasons. The debris stream from comet Tempel-Tuttle is particularly dense, and the Leonid meteoroids travel at very high velocities, nearly 45 miles per second compared to 12 miles per second for average meteoroids. Nevertheless, NASA and Department of Defense experts do not classify the risk to most satellites as serious. With proper precautions, such as pointing vulnerable systems away from the incoming meteoroids, most damage can be avoided. GSFC technicians plan to tilt ACE by 20 degrees and power down sensitive instruments to avoid electrical discharges if a meteoroid should hit.