Here's why:
* Satellite literally means "attendant" or "companion".
* In astronomy, a satellite is an object that orbits a larger object in space.
* The larger object is often called the primary, and the satellite is called the secondary.
Examples:
* The Moon is a natural satellite of Earth.
* The International Space Station is an artificial satellite of Earth.
* Mars has two moons, Phobos and Deimos, which are natural satellites.
