What Is a Celestial Body That Orbits Another Body?

Although scientists use the term celestial body quite broadly, when they refer to a celestial body orbiting another body they are generally talking about natural satellites, or moons, orbiting a larger body such as a planet or dwarf planet. Within the solar system, astronomers have identified over two hundred natural satellites.

As of 2014, scientists have confirmed the discovery of 173 natural satellites orbiting around the eight planets. Earth has one moon, Mars has two, Jupiter has 50, Saturn has 53, Uranus has 27, and Neptune has 13. Neither Mercury nor Venus have any moons. Jupiter, Saturn and Neptune all have provisional moons, which refers to moons not yet verified by the International Astronomical Union. Eight moons orbiting dwarf planets have been confirmed. Natural satellites also orbit minor planets and asteroids, with at least 200 moons orbiting minor planets. Within the asteroid belt, 76 objects have natural satellites, while four Jupiter trojans and 14 Mars-crosser asteroids also have orbiting celestial bodies. As of 2014, 39 near-Earth objects have one or two orbiting celestial bodies. Scientists believe that some of these moons may have their own moons, although no discovery of such a body has been confirmed. Jupiter's moon Ganymede is the largest natural satellite in the Solar System.