ASTEROID BELT
Beyond Mars lies the asteroid belt where millions of chunks of rock orbit the Sun in a circular path. The largest of these asteroids is 940km but most are less than 1m in diameter. We are fortunate that most are small as most of the asteroids that enter the inner solar system are from the asteroid belt. They spiral in as a result of collisions knocking them out of orbit. It is an asteroid which hit the Earth which is believed to have wiped out the dinosaurs. An asteroid hitting Earth at the time of their extinction at the Cretaceous-Tertiary boundary is known to have happened as a large crater has been found as well as a thin layer of an element called iridium which settled on the Earths surface.
One of mans greatest achievements is landing a space probe called shoemaker on an asteroid called Eros, only 18km (11 miles) in diameter which crashed into Jupiter.
It is more likely for humans to mine asteroids in the future than to live on them as they do not have an atmosphere and are too small to have a gravitational strength that is strong enough to support life.
