Comets are the most exciting heavenly bodies and have ever been the objects of man’s curiosity as well as fear. The word Comet (Figure 2.8) is derived from the Greek word Aster Kometes meaning ‘Long Haired Star’. They are made up of small ice particles and meteoric fragments. They revolve around the Sun. But their orbits are irregular. Sometimes they get very close (Perihelion) to the sun and in other times they go far away (Aphelion) from the sun.
The best known Comet, Halley’s Comet, appears once in every 76 years. The Halley’s Comet was seen last in 1986 and it will be seen again on 28th July 2061.