Asteroid moons are asteroids that orbit larger asteroids. These numbers are similar to that of comparable asteroids in the asteroid belt. Psyche is one of the most massive asteroids in the asteroid belt. Centaurs typically behave with characteristics of both asteroids and comets. The dust is thought to be generated by collisions among comets and asteroids. Research is involved in observations of near-Earth phenomena such as asteroids and comets. This is a common size for asteroids, comets, and moons. This space is populated with interstellar bodies such as stars, planets, asteroids, etc. This is behavior typical of comets but not asteroids. The outer Solar System is beyond the asteroids, including the four giant planets. Earth orbits with 10,000 near-Earth asteroids. The Vestian asteroids and HED meteorites are examples. The tradition of some astrologers casting charts with minor planets originates with these asteroids. Earth has at least five co-orbital asteroids, including 3753 Cruithne and . It is achieved by sky surveys that are designed to discover near Earth asteroids.