Astronomy defines a comet as a relatively small extraterrestrial body that consists of a frozen mass, which revolves around the sun in an elliptical orbit. It is similar to an asteroid, but the main difference lies in the fact that the comet primarily comprises of ice and dust particles along with rocky material. Comets are the leftovers from the outer cold spaces in the solar system.
A comet consists of three parts – the nucleus, the coma and the tail. The nucleus is the centre, which is hard and dark, and made out of ice, gas and rock. The gas and the dust around the nucleus form the coma. The coma is visible to us, since the sun heats the nucleus, and the coma is nothing but the gas and dust surrounding the nucleus. The power of the sun pushes the dust and gas away from the nucleus, which appears to us as the tail of the comet.
A comet consists of three parts – the nucleus, the coma and the tail. The nucleus is the centre, which is hard and dark, and made out of ice, gas and rock. The gas and the dust around the nucleus form the coma. The coma is visible to us, since the sun heats the nucleus, and the coma is nothing but the gas and dust surrounding the nucleus. The power of the sun pushes the dust and gas away from the nucleus, which appears to us as the tail of the comet.