10.9 Meteors, Meteroids, Meteorites
A meteoroid is a small sand to boulder-sized particle of debris in the Solar system. The visible path of a meteoroid that enters Earth's (or another body's) atmosphere is a meteor, commonly called a "shooting star" or "falling star". Many meteors are part of a meteor shower. A meteorite is a natural object originating in outer space that survives an impact with the Earth's surface. While in space it is called a meteoroid. When it enters the atmosphere, air resistance causes the body to heat up and emit light, thus forming a fireball, also known as a meteor or shooting star. More generally, a meteorite on the surface of any celestial body is a natural object that has come from elsewhere in space. Meteorites have been found on the Moon and Mars.

- Perseids: They are a prolific meteor shower associated with the comet Swift-Tuttle. The Perseids are so called because the point they appear to come from, called the radiant, lies in the constellation Perseus. Meteor showers occur when Earth moves through a meteor stream. The stream in this case is called the Perseid cloud and it stretches along the orbit of the Comet Swift-Tuttle. The cloud consists of particles ejected by the comet as it passed by the Sun. Most of the dust in the cloud today is approximately a thousand years old.