What is asteroid?

Asteroids, small planets are synonyms for a small group of celestial bodies floating in the solar system in orbit around the Sun. Asteroids are smaller bodies than planets but larger than meteorites and not comets.

Asteroids have quite different sizes and physical components.

433 Eros asteroid.(Photo: Wikipedia).

In the number of asteroids discovered, most of them concentrated in the asteroid belt between Mars and Jupiter, mostly with low eccentric orbits (near circular orbit). This belt is now listed as containing about 1.1 to 1.9 million asteroids larger than 1km, and millions of smaller asteroids. It is thought that these asteroids are the rest of the planetary disk and in this area the planetesimal cannot grow into planets due to Jupiter's great gravity. Although fewer Trojan asteroids have been discovered (asteroids in orbit of Jupiter), it is thought that there are many asteroids as well as the main belt.

The mass of all celestial bodies in the main asteroid belt, located between Mars and Jupiter orbit, is about 3.0-3.6x10 ^ 21 kg, or about 4 percent of Face mass Moon.

Most asteroids are classified based on two factors: the nature of their orbits and their spectral lines .

A newly discovered asteroid will be named temporarily (eg 2002 AT4). Once the asteroid's trajectory is identified, it is numbered, and can be named (433 Eros). By default, there will be parentheses around the numbers, but often people ignore these brackets.