what is an asteroid?

Answer by  gleverance (720)

The International Astronomical Union define asteroid as a small Solar System body. We don't know for sure what they are composed of, but comets that have burned off their ice and cease to produce a tail are considered asteroids. The consensus is that they are generally made of iron and other heavy metals.

Answer by  John (9008)

An asteroid is a chunk of rock moving through space. It is smaller than a planet, and slower than a comet. Asteroids can be made up of all sorts of different minerals, and vary greatly in size. Occasionally, they impact on planets. This is what created the craters on the moon.