Editing Geocentric orbit (section)

==List of terms and concepts==
{{dablink|The following words may have more than one definition or other non-Earth specific definition(s).<br>In the spirit of brevity some of the definitions have been altered or [[Truncation|truncated]] to reflect only their usage on this page.
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;[[Altitude]]: as used here, the height of an object above the average surface of the Earth's oceans ([[mean sea level]]).
;[[Analemma]]: a term in [[astronomy]] used to describe the plot of the positions of the Sun on the [[celestial sphere]] throughout one year. Closely resembles a figure-eight.
;[[Apogee]]: is the farthest point that a satellite or [[Astronomical object|celestial body]] can go from Earth, at which the  orbital velocity will be at its minimum.
;[[Eccentricity (mathematics)|Eccentricity]]: a measure of how much an orbit deviates from a perfect circle. Eccentricity is strictly defined for all [[circular orbit|circular]] and [[elliptical orbit]]s, and [[parabolic trajectory|parabolic]] and [[hyperbolic trajectory|hyperbolic trajectories]].
;[[Equatorial plane]]: as used here, an imaginary [[Plane (mathematics)|plane]] extending from the equator on the Earth to the [[celestial sphere]].
;[[Escape velocity]]: as used here, the minimum [[velocity]] an object without [[Spacecraft propulsion|propulsion]] needs to have to move away indefinitely from the Earth. An object at this velocity will enter a [[parabolic trajectory]]; above this velocity it will enter a [[hyperbolic trajectory]].
;[[Impulse (physics)|Impulse]]: the [[integral]] of a [[force]] over the time during which it acts. Measured in ([[newton (unit)|N]]·[[second|sec]] or [[pound (force)|lb]] * sec).
;[[Inclination]]: the [[angle]] between a [[reference plane]] and another [[Plane (mathematics)|plane]] or [[Coordinate axis|axis]]. In the sense discussed here the [[reference plane]] is the Earth's [[equatorial plane]].
;[[Orbital arc]]: an imaginary arc in the sky as seen from any given location on the surface of the Earth.
;[[orbital parameters|Orbital characteristics]]: the six parameters of the [[Keplerian elements]] needed to specify that orbit uniquely.
;[[Orbital period]]: as defined here, time it takes a satellite to make one full orbit around the Earth.
;[[Perigee]]: is the nearest approach point of a satellite or celestial body from Earth, at which the orbital velocity will be at its maximum.
;[[Sidereal day]]: the time it takes for a [[celestial object]] to rotate 360°. For the Earth this is: 23 hours, 56 minutes, 4.091 seconds.
;[[Solar time]]: as used here, the local time as measured by a [[sundial]].
;[[Velocity]]: an object's speed in a particular direction. Since velocity is defined as a [[Vector (geometric)|vector]], both speed and direction are required to define it.