ABSTRACT
By the end of the eighteenth century, especially after the discovery of Uranus, it was strongly believed that Bode’s Law was fundamental in nature and that the gap between Mars and Jupiter should be occupied. Astronomers searched for the missing body and on 1 January 1801 such a body was found by Giussepe Piazzi (1746-1826) who called it Ceres, after the guardian god of his native Sicily. Although the body was obviously rather small to be considered as a planet, it filled the gap in Bode’s law in a very satisfactory way. The discovery of other similar, if even smaller, bodies over the next few years was the prelude of many other discoveries of asteroids which continues to the present day. These bodies have a variety of characteristics in terms of orbit, shape, size and composition and these will now be discussed together with ideas that have been proposed concerning their origin.
