The point in the orbit of the moon or a satellite at which it is furthest from the Earth

The seven Classical Planets are seven non-fixed astronomical objects in the sky visible to the naked eye: the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn

International Astronomical Union

A region of space surrounding an astronomical object in which charged particles are manipulated or affected by that object’s magnetic field

A thin, atmosphere-like volume surrounding a planet or natural satellite

A gravitational object composed of matter. It is a theoretical alternative to the Black Hole concept from general relativity

A region of spacetime exhibiting gravitational acceleration so strong that no particles or even electromagnetic radiation such as light can escape from it

The moon revolves in its orbit in the opposite direction as the planet rotates about its axis