Meteoroid
A meteoroid is a small piece of rock or metal travelling through space.
A meteoroid is a bit of space rock or metal moving around the Sun. Most are tiny, like grains of sand or dust, but some are as big as a football or a car. Astronomers usually call anything bigger than about a metre an asteroid instead, so a meteoroid is really a small cousin of the asteroids.
Meteoroids come from two main places. Many are crumbs knocked off asteroids when they bump into each other. Others are dust left behind by comets, which shed little grains as they warm up near the Sun. Every year in August, Earth passes through a trail of grains from Comet Swift–Tuttle, and we see the Perseid meteor shower.
You cannot see a meteoroid while it is out in space, because it is far too small and dark. You only notice one when it rushes into our air and glows as a meteor. If part of it survives and lands, that piece gets a new name: a meteorite. So one rock can have three names, depending on where it is!
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Level: Beginner Ages 7 and up