Comets and Nebulas
- This is a preview of the essay.
To view the full text you must login!
The study of planets, stars, galaxies, and intergalactic and interstellar space have been going on since thousands of years ago, and as time passes humans are gaining more knowledge about the universe which we live in, and are beginning to solve some of the mysteries which have puzzled people throughout history. Some of the mysteries, which we are trying to understand more about are Comets and Nebulas. These two objects contain a lot of differences.
Comets are small icy celestial bodies which revolve around the sun. When a comet gets near the Sun, some of the ice in the comet turns into gas. The gas and loose dust which are released from the ice create a long tail that streams behind the comet. As a comet recedes from the Sun, the loss of gas and accompanying dust decreases in quantity, and the tails disappear. Some of the comets with small orbits have tails so short that they are practically invisible. On the other hand, the tail of at least one comet has exceeded 200 million mi in length. The tail and coma of a comet contains fragmentary molecules and elements like, hydrogen, carbon, nitrogen, and oxygen...