Apogee

Definition

Apogee is the point in an orbit around Earth where the orbiting object is farthest from the planet. It is one of two apsides, the other being perigee, which is the closest point.

5 Must Know Facts For Your Next Test

1. Apogee occurs when the gravitational pull from Earth on the orbiting object is weakest.
2. The speed of an object at apogee is slower compared to its speed at perigee.
3. Apogee and perigee are specific to orbits around Earth; analogous terms for other celestial bodies are apoapsis and periapsis.
4. The distance between Earth and an object at apogee varies depending on the object's orbital eccentricity.
5. Satellite orbits with high eccentricity have a greater difference between apogee and perigee distances.

Review Questions

• What happens to the speed of an orbiting object as it reaches apogee?
• How does apogee differ from apoapsis?
• Why do objects experience weaker gravitational pull at apogee?

Related terms

Perigee:

The point in an orbit around Earth where the orbiting object is closest to the planet.

Apoapsis: The point in any orbit around a celestial body where the orbiting object is farthest from that body.

Orbital Eccentricity: A measure of how much an orbit deviates from being circular.