What is difference between comets and asteroids?

Answer 1

The main difference between asteroids and comets is what they are made of. Asteroids are made of metals and rocky material, while comets are made up of ice, dust and some rocky material. Both asteroids and comets were formed early in the history of the solar system, about 4.5 billion years ago. Asteroids formed much closer to the Sun, where it was too warm for ices to remain solid. Comets formed farther from the Sun where ices would not melt. Comets which approach the Sun lose material with each orbit because some of their ice melts and vaporizes to form a tail.

An asteroid is a small, inactive body, made up of rock, carbon or metal, that orbits the Sun.

A comet is also a small, but sometimes active object, made of dirt and ice. Comets are able to be seen by their characteristic tails as they become affected by the heat of the Sun. The tail of a comet is pushed away from the Sun. It does not necessarily trail behind it.

Comets follow highly elliptical orbits, approaching the inner solar system and then retreating to a considerable distance from the Sun. If they stayed close in to the Sun, all the ice would vaporize, and they would cease to be comets. Most asteroids tend to have more nearly circular orbits, although some develop more elongated orbits as a result of gravitational interactions with the planets or other asteroids.

Asteroids have diameters anywhere from a few meters to a few hundred kilometers. Only about 200 asteroids have diameters exceeding 100 kilometers. Most rotate on their axes every 5 to 20 hours. Most asteroids in the solar system are located in the 'asteroid belt', where they orbit the sun in the space between the orbits of Mars and Jupiter. Some smaller asteroids may orbit larger asteroids as satellites. Asteroids are different from planets and moons mainly because of their much smaller size, and irregular shapes.