Asteroids are any objects orbiting the sun that aren't planets or comets.

Asteroids are mainly made of mineral and rock, whereas comets are made of dust and ice. However, the difference between planets and asteroids is changing all the time, and is the subject of debate!

You may know that Pluto used to be called a planet, but it was demoted and is no longer considered one, for example. Asteroids tend to form near the sun, and if they're big enough, the gravity they generate tends to be enough to cause them to become round like we think of planets. We tend to call these asteroids dwarf planets. So Earth is nothing more than a big asteroid!

Asteroids are rocks (or piles of rocks) in space. Since the earth is made of rocks, this means that asteroids bumping into each-other and making larger and larger asteroids in the end made the rocky planets. Earth is one of them.

Asteroids are rocks that go around the sun. Asteroids sometimes come down to the earth. Or, when we see them falling in the sky, we call them 'shooting stars.'

Meteoroid: A small particle from a comet or asteroid orbiting the Sun.
Meteor: The light phenomena which results when a meteoroid enters the Earth's atmosphere and vaporizes; a shooting star.
Meteorite: A meteoroid that survives its passage through the Earth's atmosphere and lands upon the Earth's surface. Mar 31, 2014 asteroids