On the first day of January 1801, Giuseppe Piazzi discovered an object which he first thought was a new comet. But after its orbit was better determined it was clear that it was not a comet but more like a small planet and it was therefore named asteroid. The proper name of the first asteroid detected is Ceres¹. Three other small bodies were discovered in the next few years (Pallas, Vesta, and Juno). By the end of the 19th century several hundred asteroids were known.