Most of the frozen ice in a comet vaperizes after the comets many trips around the sun?

Answer 1

Comets are made up of three distinctive parts: the nucleus, the coma, and the tail. If a comet passes close to the sun enough times, it loses nearly all of the frozen ice that trail after in its tail and surrounding it in the coma.

Answer 2

That's what we expect. The comet has a finite mass; it can't refuel when it's out in the outer solar system and recharge. So at some point, the "dirty snowball" that we believe most comets are will eventually melt and disintegrate. The solar system is something upwards of 4.5 billion years old; a comet can't last THAT long.

Which is where Danish astronomer Jan Oort comes into the picture. He theorized that there must be some vast area, very far from the Sun, that serves as a repository of comets. SOMETHING, he thought, might occasionally perturb one of these fossil fragments of the solar system from their frozen darkness and cause them to drop into the inner solar system where they might become new comets. The name of this area, which has never actually been discovered even though it makes perfect sense, is the "Oort cloud".

There are even theories that there may be something larger out there, small and dark, orbiting the Sun perhaps a half-light year out, which passes through or near the Oort cloud periodically, causing a rain of comets. These comets might be dangerous to Earth, especially if there were many of them in a small space of time. The proposed name for this comet-disturbing mass (a large planet, or perhaps a failed brown dwarf star) was "Nemesis". So far, there has been no actual evidence that an object like Nemesis might exist, but space is BIG.

Answer 3

They sublimate and form one component of the tail of the comet.

Gas and sublimated ices expand and can rush away from the comet's surface at considerable speed. The reaction (pressure on the comet's surface) can noticeably alter the comet's orbit.

Answer 4

As a comet approaches the sun, the heat causes the frozen ice and other volatile materials on its surface to vaporize, creating a glowing coma and tail. This process is known as outgassing and is what gives comets their characteristic appearance when they come near the sun.

Answer 5

To put it simply, the sun is on fire and generates a lot of heat. As a comet gets close enough to that heat, it becomes warm enough for the ice to melt.

Answer 6

Absorption of heat energy from the surroundings of the ice cube.