Kid's illustration a comet.
Comets are the wanderers of our solar system.

Icy Travelers

Comets are big chunks of ice, rock and gas. They are dirty snowballs made of leftovers from the beginning of our solar system. Comets get their name from the Greek word "kometes" (long hair) -- a reference to their tails.

Color image of comet in space.
As a comet approaches the sun,
does its head or tail lead the way?
What about when it starts going
away from the sun?

Comets are mysterious. Scientists think they might be able to tell us about the origins of our solar system.

Comets orbit the sun like planets. Most comets orbit way out beyond the orbit of Neptune. A few comets close enough for us to see from Earth probably come from an area past Neptune called the Kuiper Belt. When Earth passes through the tail of a comet, we see a meteor shower. It can take a comet hundreds or even millions of years to go once around the sun. On Earth, it only takes 365 days. Most comets come from a super distant ring of debris around our solar system called the Oort Cloud.

Unless you could travel way out beyond Pluto, it would be hard to stand or land on a comet. When comets get close to the sun, they begin spewing gas and dust. The debris form the head -- or coma -- and a tail. The tail always points away from the sun. The only solid part is the nucleus in the middle.

If you did manage to land on a comet, you might end up getting blasted into space on a jet of gas and rock. Or, if your comet got too close to the sun, it would break up completely.