GENERAL KNOWLEDGE

Detailed explanation-1: -Some astronomers have referred to comets as “dirty snowballs” or “icy mud balls” because they are composed mainly of ice with dust and fragments of rock. The ice can be both water ice and frozen gases. Astronomers believe that comets may be composed of the very material that formed the Solar System.

Detailed explanation-2: -Comets are cosmic snowballs of frozen gases, rock, and dust that orbit the Sun. When frozen, they are the size of a small town. When a comet’s orbit brings it close to the Sun, it heats up and spews dust and gases into a giant glowing head larger than most planets.

Detailed explanation-3: -At the heart of every comet is a solid, frozen core called the nucleus. This ball of dust and ice is usually less than 10 miles (16 kilometers) across – about the size of a small town.

Detailed explanation-4: -Whipple believed they were like dirty snowballs-large chunks of water ice and dust mixed with ammonia, methane and carbon dioxide. As the snowball approached the Sun, its outer ices began to vapourise, releasing large amounts of dust and gas which formed the characteristic tails.