Not so clean, Tail-star

In July 1994, the fragments of a comet crashed into Jupiter creating huge black spots in the planet’s atmosphere. It was a rare sight for the astronomers around the world. The comet was Shoemaker-Levy 9 discovered by Eugene and Carolyn Shoemaker and David Levy in 1993. Do you know what is a comet? It is a ball of ice, rock and dust. The ice and rock core of a comet is called the nucleus. As a comet approaches the sun, the ice in the nucleus begins to vaporize due to heat. The vapours along with dust are then pushed away from the nucleus by the solar wind. This forms the tail of a comet. Water vapour and dust also form a halo around the nucleus, which is called the coma.  Thus a comet looks like a luminous broom in the sky. A comet occurs in the sky very rarely-maybe once in a thousand years. Many ancient cultures including ours believed that a comet symbolized bad luck. In 1682, Edmund Halley, a British astronomer, observed a comet. He discovered that its path was similar to the comets seen in 1531 and 1607. Halley calculated the orbit of the comet to be 76 years and predicted that the comet would return in 1758. When the comet appeared on the Christmas Eve of 1758 it was named Halley’s comet. In 1986, the European spacecraft-Giotto took many photographs of the nucleus of Halley’s comet. These revealed that the nucleus was too dark, darker than coal. Just imagine that. Halley’s comet is different from others because it’s too big and has a well-defined orbit. After hearing all this if you are curious to see the Halley’s comet in reality you will have to wait for a long time, for it will reappear in 2061.

Web references :

Comets
Jupiter
Planets
Poisonous Gases.