Asteroids

Ceres is the largest known asteroid with a diameter of about 950 km. This asteroid is so great that it can be classified as a dwarf planet.

Asteroids too small to have a spherical shape which formed bodies in space under the action of gravity. Therefore asteroids are generally ellipsoid, dumbbell or even take an odd shape.

Asteroids are rarely whole structure. Increasingly, they are more like a pile of rubble held together by its overall weight.

Most asteroids are rocky or composition, or a metal. Metallic asteroids heavier and have more chances to pass the Earth's atmosphere without any obstacles and land. Stony asteroids usually burned in the atmosphere or when they are very large, closer to the surface to explode.

Asteroid entered the Earth's atmosphere is called a meteor that fell to Earth - a meteorite.

If you combine all the asteroids in the asteroid belt, they form a cosmic body less than 1500 km in diameter, which is less than half of the moon.

Get the name of the asteroid may only after its orbit is more or less accurately calculated. There are times when an asteroid gets name only a few decades after the discovery.

Represent the global danger may asteroids more than 10 km in diameter. All asteroids of this size are known to astronomers and are on orbits that can not lead to a collision with the Earth.