Asteroids, Meteors, Comets.

Asteroids
1. Asteroids are bodies made up of metals and rocks.
2. Most asteroids are found in the asteroid belt between the orbits of Mars and Jupiter.

Meteoroids
1. Meteoroids are small pieces of roc or metal floating in the outer space.
2. When Meteoroids float near to the earth, they may be drawn into the Earth's atmosphere due to gravity.
3. Meteoroids which enter the earth's atmosphere are called meteors.
4. Most meteors will burn up when they entre the Earth's atmosphere due to friction.
5. Meteors which do not burn completely and reach the Earth's surface are called meteorites.

Comets
1. A comet is a lump of ice which consists of frozen gasses and dust.
2. When a comet comes near to the Sun, the ice at its centre melts, causing it to glow. A long tail of gas and dust is visible.