Asteroids in the solar system

The zone of asteroids

The interplanetary space is far from empty, it is littered with dust and material dating from the creation of the solar system. Asteroids and comets and rocky metallic objects, moving at breakneck speed around the planets and our Sun. An asteroid is a celestial object, not observable to the naked eye because of its small size, which varies from a few tens of meters to several hundred kilometers in diameter. These objects are part of our solar system revolve around him since its inception. The objects of less than 50 meters in diameter are called meteorites. Those are not satellites of planets, but debris from the protoplanetary disk that failed to come together into planets, during their training. The first asteroid was discovered by accident 31 December 1800 by the Italian Giuseppe Piazzi, director of the observatory of Palermo, Sicily. By observing the constellation Taurus, he saw an unidentified object moving very slowly in the night sky.
His colleague, Carl Friedrich Gauss determined the exact distance of the unknown object and put that star between Mars and Jupiter. Piazzi named it Ceres, named after the Greek goddess who brings the sap of the Earth and grows the seedlings in the spring.

Between 1802 and 1807, three more bodies were discovered, Pallas, Juno and Vesta. In 1868, 100 asteroids were known. The discovery of a certified 000th took place in 1921 and 000th in 1989 10. In March 2006, there were 129,436 registered minor planets. The probe NEAR Shoemaker (Near Earth Asteroid Rendezvous) was launched February 17, 1996 by NASA to study in detail Eros, one of the largest near-Earth asteroids. This probe gave a complete mapping of Eros in 2000, it was finally laid safely on the asteroid, February 12, 2001 and sent its last signal 28 February 2001. It is estimated that several million the number of asteroids that frequent the area of space between Mars and Jupiter...
The Kuiper Belt contains over a trillion comets and there are at least as much in the Oort Cloud. All these cosmic objects, are subject to the laws of celestial mechanics and ballet around the Sun is chaotic in nature. The slightest disturbance is enough to disrupt their orbit and make it dangerous for us.

Image: The details of Eros for the NEAR probe that landed safely on the asteroid, February 12, 2001.

Number of asteroids

Between Mars and Jupiter (from 300 to 600 million km from the Sun).

The asteroids are mainly located in the main belt between the orbits of Mars and Jupiter. There are hundreds of thousands of items listed.
All the objects could have formed a planet in this area but the gravitational perturbations of Jupiter have not helped. Jupiter has played the role of protector of life on our planet. Without Jupiter, the bombing Earth would be 1000 times more common.

In the Kuiper belt (between 35 and 100 AU from the Sun).

This area contains icy objects, and therefore are not strictly asteroids.
This belt is quite a nursery of comets. The first member was discovered in 1992. Now number just over 1000.
The British call the asteroids of this type of "cubewanos." The largest identified so far is Quaoar (1280 km in diameter).

In the Oort cloud (between 20,000 and 150,000 AU vicinity).

This area of the sky, the residue of the original nebula, contains billions of nuclei of comets and is the source of most new comets entering the central regions of the solar system.
The Oort Cloud is the reservoir of long-period comets. This region of the solar system has a diameter 1000 times that of the solar system as we know it with only eight planets.