Comets

Composition

Comets are composed of rocky material, ice, and dust, which is why they are nicknamed "dirty snowballs."

Formation

Comets are formed after the merging of ice dust grains and debris left over from the solar system's formation.

Activity

Ice on the comet's surface turns into gas, which forms a coma around the nucleus and even a tail. This happens when comets come close to the sun. The ice goes from solid to gas. After this happens, the coma and tail are redirected from the sun.

Three Famous Comets

Halley's Comet:

It was the first comet seen as a constant visiter in our solar system.

Hyakutake:

Passed close to Earth in 1996; Known as the Great Comet of 1996

Comet Shoemaker-Levy9:

The first comet to collide with a planet. This comment collided with Jupiter in 1994.