📘 Definition
In an elliptical orbit around Earth, the apogee is the point farthest from Earth's centre, and the perigee is the point closest to Earth. For a circular orbit, apogee equals perigee. In a GTO (Geostationary Transfer Orbit), the perigee is typically ~250 km and the apogee ~35,786 km. A satellite travels fastest at perigee and slowest at apogee (Kepler's second law). These terms apply only to Earth orbits; for orbits around the Sun, the equivalent terms are aphelion and perihelion.