A meteoroid is a small natural object composed of rock or metal that travels in outer space. These celestial bodies are generally significantly smaller than asteroids, ranging in size from small dust particles up to meters in diameter. When a meteoroid enters the atmosphere of a planetary body, friction with the surrounding gases causes it to heat up and often vaporize, producing a visible streak of light commonly called a meteor. If the surviving fragments of a meteoroid are large enough to reach the ground, they are classified as meteorites. The study of meteoroids and their remnants provides crucial information regarding the composition and formation history of the solar system.