Give a detailed account of the various effects caused by the comet to the earth ?
Answers
Comets have been called "dirty snowballs." They are small celestial objects, made of ice, gas, dust, and a small amount of organic material, that orbit our Sun. There are about 1000 known comets and more are discovered each year. Every comet has a nucleus, a stable, porous central mass of ice, gas, and dust that if often between 1 and 10 kilometers (0.6 to 6 miles) in size. The ice is made of varying amounts of water, carbon dioxide, ammonia, and methane. The dust may contain hydrogen, oxygen, carbon, nitrogen, silica, and some metals. The nucleus may have traces of hydrocarbons. As comets move close to the Sun, they develop tails of dust and ionized gas. Comets have two main tails, a dust tail and a plasma tail. The dust tail appears whitish-yellow because it is made up of tiny particles — about the size of particles of smoke — that reflect sunlight. Dust tails are typically between 1 and 10 million kilometers (about 600,000 to 6 million miles) long. The plasma tail is often blue because it contains carbon monoxide ions. Solar ultraviolet light breaks down the gas molecules, causing them to glow. Plasma tails can stretch tens of millions of kilometers into space. Rarely, they are as long as 150 million kilometers (almost 100 million miles). A third tail of sodium has been observed on Comet Hale-Bopp.