mringham
commented
4 months ago | Term | Definition |
|---|---|
| Epoch | moment in time used as a reference point (timestamp) |
| Perihelion | point of orbit where the object is the closest to the sun |
| Argument of the perihelion | Rotating axis of the orbit around the focus, the rotation angle is the argument of perihelion ω. -- The angle between the ascending node and the perihelion |
| Semimajor axis | the mean distance from the center of the orbit to either focus (half the length of the longest diameter of the elliptical orbit |
| Eccentricity | measures how non-circular an orbit is: e = 0 indicates a circular orbit, 0 < e < 1 indicates an elliptical orbit, e = 1 indicates parabolic orbit, e > 1 indicates a hyperbolic orbit |
| Inclination | angle at which an object’s orbit around a central body is tilted in comparison to the reference plane |
| Node | intersection of the orbit plane of a celestial body with the ecliptic as projected on the celestial sphere |
| Mean anomaly | fraction of an elliptical orbit’s period that has elapsed since the orbiting body passed the perihelion |