It is believed that the asteroid belt, the area between Mars and Jupiter, may at one time have been the location of another planet which was pulverized by a cosmic collision with another body such as a comet travelling through our solar system. Another contrasting theory is that the asteroid belt represents material from the early stages of our solar system which simply failed to form into planetary forms.

To date, approximately 338 asteroids have been identified with Ceres, the largest known asteroid, measuring over 900 kilometers across and to be comprised of water by up to 25%! In fact more than 200 asteroids have been discovered so far which measure at least 100 kilometers in diameter. For an extensive list of asteroids with associated details (discoverer etc), click here.

Note: Asteroid Vesta depicted below was discovered by German astronomer Heinrich Wilhelm Olbers in 1807 and five years following his earlier discovery of asteroid (and minor planet) Pallas in 1802. Vesta is one of the larger asteroids and whose dimensions are in the hundreds of kilometers. It is characterized with a slightly eccentric orbit (e=0.089) which requires 3.63 years for one complete orbit around the sun. Its perihelion and aphelion distances are 2.153 and 2.571 AU, respectively, with a magnitude at opposition of approximately 5.1.