Understanding Perigee: The Point of Closest Approach to Earth

Perigee (or perigree) is the point in the orbit of a satellite or other celestial body where it is closest to the Earth or another celestial body. At this point, the satellite or celestial body is at its shortest distance from the center of the Earth or other celestial body. The opposite point, where the satellite or celestial body is farthest away, is called apogee.
Perigee is an important factor in determining the orbit of a satellite or celestial body, as it affects the distance and speed of the object at different points in its orbit. For example, a satellite in a low Earth orbit (LEO) will have a shorter perigee than a satellite in a geostationary orbit (GEO).
Perigee is also used to describe the closest approach of a comet or asteroid to the Earth. In this context, the term "perigee" is often used interchangeably with "perilune," which refers specifically to the point where the comet or asteroid is closest to the Moon.