Meteoroids are small bodies that travel through space. Meteoroids are smaller than asteroids; most are smaller than the size of a pebble. Meteoroids have many sources. Most meteoroids come from asteroids that are broken apart by impacts with other asteroids. Other meteoroids come from the Moon, from comets, and from the planet Mars.
Meteoroids orbit around the Sun; different meteoroids travels at different speeds and in different orbits. Some meteoroids orbit together (called stream component); these are probably comet remnants). Other meteoroids are in sporadic (seemingly random) orbits.
The fastest meteoroids travel at roughly 26 miles per second (42 km per second) through space.
Meteoroids have done minor damage to spacecraft, including the Hubble Space Telescope (HST). About 100 tiny craters and chipped areas have been found on the HST; they were caused by impacts with tiny meteoroids.
Meteors and meteoritesEdit
A shooting star is really a small piece of rock or dust that hits Earth's atmosphere from space. It moves so fast that it heats up and glows as it moves through the atmosphere. Shooting stars are actually what astronomers call meteors. Most meteors burn up in the atmosphere before they reach the ground. However, once in a while a meteor is large enough than some of it survives and reaches Earth's surface.