Space Station Info >> Meteors

Meteors

Most of us probably have seen meteors or shooting stars. A meteor is the flash of light that we see in the night sky caused by the friction of a meteoroid passing through our atmosphere. A meteoroid is an interplanetary chunk of matter smaller than a kilometer and frequently millimeters in size. (Note that the term "meteor" refers to the flash of light caused by the meteoroid, not the meteoroid itself.) Most meteoroids that enter the Earth's atmosphere are so small that they vaporize completely and never reach the planet's surface. If any part of a meteoroid survives the fall through the atmosphere and lands on Earth, it is called a meteorite. Although the vast majority of meteorites are very small, their size can range from about a fraction of a gram (the size of a pebble) to 100 kilograms or more (the size of a huge, Earth-destroying boulder).

Asteroids are generally larger chunks of rock that come from the asteroid belt situated between the orbits of Mars and Jupiter. Comets are asteroid-like objects enclosed with ice, methane, ammonia, and other compounds that form a coma and sometimes a visible tail whenever they orbit close to the Sun. As a comet rides through the solar system, it leaves little particles in its wake. If the Earth's orbit intersects this "wake" of particles, we see a meteor shower as the particles rain down through Earth's atmosphere.

Also see

Regions Where The Comets Are Found
Orbits Of Comets
Asteroids