What part of a comet vaporizes after many trips around the sun?

Answer 1

After many trips around the Sun, the ice in the comet's nucleus has completely vaporized and all that is left is the dust and rock, which are spread throughout the orbit of the original comet.

Answer 2

It will usually move around the Sun in an ellipse. Such an ellipse often has a high excentricity - meaning the difference between the closest and the farthest distance from the Sun can be rather large.

If, at its apapsis, such a comet gets close to the Sun, the Sun's heat will gradually make it evaporate.

Answer 3

There are millions and millions of comets that go around the Sun . . . some close, some hugely far away. Comets always are going around the Sun, just like Earth or Mars. After long-range comets orbit close to the Sun, they start orbiting farther and farther away from the Sun, returning to the Kuiper Belt or Oort Cloud and getting ready to begin another turn around the Sun. Some shorter-range comets orbit from within the Solar System.

The Kuiper Belt and Oort Cloud exist farther from the Sun than all of the planets, and are composed of icy particles, mostly. The Oort Cloud extends away from the Sun to its limit at about 1,000 times farther than does the Kuiper Belt.

Answer 4

The volatile materials, such as ice and gases like water, carbon dioxide, and methane, vaporize from the comet as it gets closer to the sun and heat increases. This process forms a glowing coma and a tail that point away from the sun due to solar wind and radiation pressure.

Answer 5

It releases gas or dust.

Answer 6

Comets don't orbit the moon. They orbit the sun. After several trips they may lose all their volatile materials and resemble rocky asteroids.