Definitions

There's a lot of big words used on this site and we hope to help define a few of them here:

Orbit: When one object goes around another in a generally circular fashion. Some orbits are not perfectly round.
Perehelion: In a orbit that is not perfectly round this would be the point at which the body is closest to the object it orbits.
Aphelion: In a orbit that is not perfectly round this would be the point at which the body is farthest to the object it orbits.
Mass: This is a measure of how much stuff there is in a body. This is based on balance measures so the body will be the same mass no matter what planet it's on.
Body: The whole thing that we're talking about. e.g. The body of the earth would include the rock, water and air all in one.
Temperature: We try to keep to Centegrade when quoting temperatures.; Sometimes we use Kelvin which uses the same scale as Centegrade except 0°K = -273°C.; If you want to convert to Farenheight, use this formula: ( °C x 1.8 ) + 32 = °F
Astronomical Unit (AU): The average distance from Sol to the Earth is equal to one astronomical unit or 1AU.
Inclination: Also called Orbital Inclination. It is the angle between the orbital plane and the plane of reference. e.g. The Earth and Mars have the same orbital plane as the equator of the Sun (plane of reference) or a low inclination. Pluto's orbital plane is at a higher inclination to the Sun's plane of reference.
Orbital Plane: If the orbit of an object was turned into a disk this would be the orbital plane.

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