Comets

Have you ever wished upon a shooting star? Are you sure it was a shooting star? Next time you catch a glimpse of a gleaming, falling object in the night sky, you might be witnessing the passing of a comet.

Since comets are made from dust and ice they are also known as "dirty snowballs" or "icy mudballs." The ice portion of the comet isn't just made of water, but also frozen gases that burn off when the comet nears the sun. When the gases burn off it ends up looking like the comet is glowing.

The comet follows a path (called an orbit) around the sun just like the planets. However, while the earth takes 365 days to go once around the sun, it takes the average comet a few hundred years to do the same. Comets are only visible to the human eye when they get close to the sun, which means we can only see them for a few months every few hundred years. Once a comet has passed by the sun about 500 times, (which will take hundreds of thousands of years) all of its gases will burn off and the comet will end up looking like an ordinary meteor or asteroid.

The comet is made up of five distinct parts:

Nucleus: This is the center of the comet and is mostly made of ice and gas with a small amount of dust and other solids.

Coma: This is a dense cloud of water, carbon dioxide and other neutral gases that surrounds the nucleus.

Hydrogen cloud: The hydrogen cloud is a huge but very thin envelope of hydrogen gas around the comet. It can be often be millions of miles wide.

Dust tail: This is the most noticeable part of a comet to the unaided eye. It is made up of miniscule dust particles that are forced off the nucleus by escaping gases and can be up to 7 million miles (10 million kilometers) long.

Ion tail: This is the part that, when close to the sun, starts to glow. It is made up of electrically charged ions and can be up to several hundred million miles long.

So, how does somebody discover a comet? Well, comet hunters usually spend hundreds of hours scouring the night sky. Luckily Kidzworld has put together some tips for the amateur comet watcher to save you some time.

Make sure you know what a comet looks like. Check them out here or read up on them at your public library.

Head out of the city, to somewhere without many lights.

Use binoculars or a telescope, you'll have a much easier time finding a comet.

Look towards the east about 30 minutes before sunrise or to the west about 30 minutes after the sun sets. This makes it easier for you to spot the comets tail.

Now you're ready to be the biggest astronomy buff on the block. Good luck and happy hunting!

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