Comets and Meteors

The cycles of the Sun, Moon and Stars are very regular, and we know where they will be for hundreds of years. Not everything in space is like that, though. The bright tail of a comet and the streak of a meteor are two of the most beautiful surprises in nature.

Meteors, asteroids, and comets are not really separate things, just different forms of the same thing - space debris (rocks). Very large chunks of rock in space are called asteroids. Thousands of asteroids orbit between Mars and Jupiter in the Asteroid belt. Meteoroids are smaller chunks of rock in space. When they enter our atmosphere they start to burn, and are called meteors. Meteors streak across the sky, blazing bright for only a few seconds. What we call "shooting stars" are actually meteors. As the Earth moves in its orbit around the Sun, it occasionally crosses the stream of dust left by a comet, and this causes a meteor shower.

Sometimes meteors are large enough to survive the fiery trip through the atmosphere, and actually hit the ground. These are called meteorites. Most meteorites are small and they cause very little damage when they hit. Most of them land in water, which covers 2/3 of our planet. There are only two documented cases of a person being hit by a meteorite.

Comets are also chunks of rock, but they have ice mixed in as well. They have very long orbits, and when they come close to the Sun, the heat boils off frozen ice from them, and pushes it into a long, bright tail. Comets are much bigger than meteors and they do not have to enter our atmosphere to be seen. Comets can be seen for many weeks as they move slowly across the sky. Probably the most famous comet is Halley’s Comet. It returns every 76 years, right on time. A comet that was here recently was the Hale-Bopp comet.