What causes a meteor shower?


METEOR showers occur when the earth in its orbit around the Sun passes through debris left over from the destruction of comets. Although the earth’s orbit around the Sun is almost circular, most comets travel in orbits that are highly elongated ellipses. As a result, some comets have orbits that intersect or partially overlap the earth’s path.

Since a comet’s nucleus is made up of a combination of icy materials and loosely consolidated “dirt,” when a comet is heated by passing close to the Sun, it more or less slowly disintegrates, producing the visible tail. The rocky debris, consisting of mostly sand-size particles, continues in an elongated orbit around the Sun close to that of its parent comet.

When the Earth intersects this orbit in its annual trip, it can run into this debris, which burns upon entry into the earth’s atmosphere, producing a visible shower of meteors. But not to worry! The meteoroids are usually small, from a dust particle to boulder size.

They are small enough to quickly burn up in our atmosphere, so there’s little chance any of them will strike Earth’s surface. But there is a good chance that you can see a beautiful shooting star show in the middle of the night!