Apogee is the farthest point of a body’s orbit from the Earth, while perigee is the closest. Other terms exist for different celestial bodies, such as aphelion and perihelion for objects orbiting the sun. Apogee is at minimum orbital speed and has low kinetic energy and high potential energy. The apogee of many bodies is not fixed and varies.
The apogee is the point at which a body is in its farthest orbit from the Earth. The opposite of apogee, the point at which an orbiting body is closest to the earth, is perigee. Apogee is an Earth-specific term, and other terms exist for different celestial bodies.
Apse, for example, is a generic term used to describe the point at which an orbiting body is furthest from or closest to its orbital center. The specific generic term for the farthest point is apoapsis and the term for the closest point is periapsis. For objects orbiting the sun, the term aphelion is used to describe the farthest point, while perihelion describes the closest point.
The word apogee comes from the Greek prefix apo- meaning ‘far’ and the word gaia meaning ‘land’. Apogee is a French derivation of the Latin term apogaeum from the Ptolemaic
Greek origin.
When a body is at its apogee, it is also at its minimum orbital speed. If you see a pendulum-like orbit, it becomes easy to visualize. As the object moves away from the center of its orbit, its speed slows down to apogee and reverses its course. At apogee, its kinetic energy is at its lowest point and its potential energy is at its highest. Conversely, when an object is at perigee it has its maximum kinetic energy and minimum potential energy, and is at its peak velocity.
The apogee of many bodies is not a fixed number, although it tends to be very close to each orbit. When the moon’s apogee, for example, occurs on a new or full moon, the distance is greater than at other times. Apogee peaks for the moon include August 4, 2005, when moon apogee was 406.628 km (252.667 miles), and September 22, 2006, when moon apogee was 406.499 km (252.587 miles). In contrast, the perigees of the moon fall within a radius of 356.410 km (221.460 miles).
Protect your devices with Threat Protection by NordVPN
