What are comets?

Explanation

Comets are the celestial bodies which revolve around the Sun in highly elliptical orbits. A comet generally appears to have a bright head with a long tail. The length of the tail grows in size as it approaches the Sun. The tail of a comet is always directed away from the Sun. Many comets are known to appear periodically. Halley.s comet appears after nearly every 76 years.