The first discovered asteroid Ceres was first discovered in 1801 by Giuseppe Piazzi. At that time, the asteroid known as a planetoid.
Already as many as hundreds of thousands of asteroids in our solar system and now found a new discovery that an average of 5000 pieces per month. On August 27, 2006, from a total of 339,376 registered minor planets, of whom 136,563 have orbits sufficiently well known so that it can be given permanent official numbers. Among the planets, 13,350 have official names (trivia: about 650 of these names requires identification). But the lowest number of unnamed minor planet is (3360) 1981 VA; minor planet named after the top number (except the dwarf planet Eris and 134 340 136 199 Pluto), namely 129 342 Ependes.
Now it is estimated that asteroids with a diameter of more than 1 km in the solar system solar totaling between 1.1 to 1.9 million. Largest asteroids in the inner solar system, that is 1 Ceres with a diameter of 900-1000 km. Two asteroid belts inner solar system, which is 2 Pallas and 4 Vesta; both have a diameter of ~ 500 km. Vesta is an asteroid belt main thing is sometimes visible to the naked eye (in some fairly rare occurrence, which is close to the Earth asteroids can be seen without technical assistance; see Apophis 99 942).
The mass of the asteroid Main Belt is estimated to about 3.0-3.6 × 1021 kg [4] [5], or approximately 4% of the mass of the moon. From all this, 1 Ceres 0.95 × 1021 kg mass, 32% of the total. Then the densest asteroid, 4 Vesta (9%), 2 Pallas (7%) and 10 Hygiea (3%), making this estimate to 51%; three onwards, 511 Davida (1.2%), 704 Interamnia (1.0%) and 3 Juno (0.9%), only add 3% of its total mass. The number next asteroid is increasing exponentially, although the mass of each drop. It is said that the asteroid Ida has a satellite named Dactyl.
