Given two objects of which one orbits the other, for example a planet and a satellite, apoapsis is the point in the satellite's orbit which is furthest (at the greatest distance) from the planet.
- If the object orbits the Earth, it's also known as apogee.
- If the object orbits the Sun, it's also known as aphelion.
- If the object orbits the Moon, it's also known as apolune.