Orbits

In astronomy, an irregular moon, irregular satellite or irregular natural satellite is a natural satellite following a distant, inclined, and often eccentric and retrograde orbit.

The lunar nodes are the orbital nodes of the Moon, that is, the points where the orbit of the Moon crosses the ecliptic.

The orbital speed of a body, generally a planet, a natural satellite, an artificial satellite, or a multiple star, is the speed at which it orbits around the barycenter of a system, usually around a more massive body.

Tidal locking (also called gravitational locking or captured rotation) occurs when, over the course of an orbit, there is no net transfer of angular momentum between an astronomical body and its gravitational partner.

In classical physics and special relativity, an inertial frame of reference (also inertial reference frame or inertial frame, Galilean reference frame or inertial space) is a frame of reference that describes time and space homogeneously, isotropically, and in a time-independent manner.

In astronomy, Kepler's laws of planetary motion are three scientific laws describing the motion of planets around the Sun.

A geostationary orbit, geostationary Earth orbit or geosynchronous equatorial orbit (GEO) is a circular orbit 35,786 kilometres (22,236 mi) above the Earth's equator and following the direction of the Earth's rotation.

The Moon orbits Earth in the prograde direction and completes one revolution relative to the stars in approximately 27.

An apsis (Greek: ἁψίς; plural apsides /ˈæpsᵻdiːz/, Greek: ἁψίδες) is an extreme point in an object's orbit.

In physics, the n-body problem is the problem of predicting the individual motions of a group of celestial objects interacting with each other gravitationally.

In astronomy, lunar orbit (also known as a Selenocentric orbit) refers to the orbit of an object around the Moon.

The Interplanetary Transport Network (ITN) is a collection of gravitationally determined pathways through the Solar System that require very little energy for an object to follow.

In orbital mechanics, mean motion (represented by n) is the angular speed required for a body to complete one orbit, assuming constant speed in a circular orbit which completes in the same time as the variable speed, elliptical orbit of the actual body.

In astrodynamics or celestial mechanics, a hyperbolic trajectory is the trajectory of any object around a central body with more than enough speed to escape the central object's gravitational pull.