Perigee
This article is about the astronomical term. In architecture, apsis is also the plural of apse
In astronomy, an apsis is the point of greatest or least distance of the elliptical orbit of a celestial body from a center of attraction. The point of closest approach is called the periapsis and the point of farthest approach is the apoapsis.
According to Kepler's laws of planetary motion, as a body approaches the periapsis it will increase in velocity and as a body approaches the apoapsis it will decrease in velocity.
When the body the orbit is around is known, more specific names are often used.
| Body being orbited | Closest approach | Farthest approach
|
|---|
| Earth | perigee | apogee
| | The Sun | perihelion | aphelion
| | The Moon | perilune | apolune
| | a black hole | perimelasma | apomelasma
|
Referenced By
2003 | 2003 in science | As of 2003 | Keplerian elements | Orbital element | Orbital elements
|
