Meteors happen when a small speck of dust burns high in the air above us. When the Earth passes close to the orbit of a comet, the comet dust hits our atmosphere and makes meteors. This can happen even when the comet is far, far away, because the comet left some dust behind. Most meteoroids are smaller than a grain of sand. Meteoroids hit the Earth's atmosphere at super high speed, about 130,000 miles per hour.
Meteors usually last just a second or two.
Sometimes people get comets and meteors mixed up. A comet is different from a meteor. Comets are balls of ice that orbit around the sun. When comets come close to the warm sun, some of the dusty ice changes into dusty gas. The gas and the dust form a tail that we can see from Earth.