For an object moving in an elliptical orbit about another celestial body, the point of closest approach is called the periapsis (from the Greek peri = near). At this point in the orbit, the object is travelling at its greatest speed (Kepler’s Second Law).

The periapsis is equivalent to the:

The point of maximum distance in the orbit is called the apoapsis.

A planet at perihelion in its elliptical orbit around the Sun.
The Moon at perigee in its elliptical orbit around the Earth.

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