Asteroids represent small rocky space bodies which can tell a lot of things of creation and development of our Solar system. Asteroids have no atmosphere.
Asteroids call the cold space objects of the Solar system consisting of ice and stones. Such celestial bodies there are much less planets of terrestrial group, irregular shape have also no atmosphere. Asteroids move on own orbit around the Sun like classical planets. The name of similar objects in translation Greekof language means ""similar to a star"".
The absolute majority of asteroids are much less in sizes, than planets.
What is a belt of asteroids
The most part of the asteroids opened for today it is concentrated in the area between Mars and gas giant Jupiter. The area in a form represents a ring which surrounds the Sun and separates internal planets and from external. Also this area is called still the main belt of asteroids and the main belt, with the purpose to emphasize its distinctive features from other similar congestions.
Belt of asteroids for today the largest studied area of a congestion of asteroids.
In the recent past the scientists tried to unite them by origin and allocated several groups on the basis of their characteristics. It is supposed that in very distant past each such group was the former one big asteroid which further for any reasons, it is possible owing to space disaster, scattered on splinters which are nowadays observed by astronomers. Near an orbit of Jupiter there are two areas in which asteroids can get to a gravitational trap. These are Lagrange's points, one of which is at distance in 1/6 before an orbit of Jupiter, and another - in 1/6 behind it. Local asteroids are called as Trojans, and receive names of heroes of the Trojan war. In the opposite direction there is a group Greeks. Also the group of near-earth asteroids which orbits are crossed about terrestrial is allocated. Such asteroids approach rather close Earth (closer, than the Moon) therefore there is a risk of collision of any of them.
History of detection of a belt of asteroids
In 1776 the German astronomer Johann Titsius the distance from the Sun to Saturn, the known planet last at that time, was divided into 100 pieces. The distance to Mercury was to equal 4 pieces, to Venus - 7, to Earth - 10. There was a theory that between Mars and Jupiter there has to be not discovered planet. In 1800 the scientific group which was engaged in search of the ""gone"" planet was organized. The area, now known as a belt of asteroids, was divided into parts for convenience of a research. The first large asteroid, now the dwarf planet - Ceres became result of observations.