Glossary


This glossary is a compilation of terms that may or may not be on this website. They are listed in alphabetical order to help you find them

Altitude
The distance between the surface of the Earth and a satellite.
Apogee
The point in the orbit of the moon or of an artificial satellite most distant from the center of the earth.
Ecliptic Plane
The great circle representing the apparent annual path of the sun; the plane of the Earth's orbit around the sun; makes an angle of about 23 degrees with the equator; "all of the planets rotate the sun in approximately the same ecliptic"
Ellipse
A closed plane curve resulting from the intersection of a circular cone and a plane cutting completely through it; "the sums of the distances from the foci to any point on an ellipse is constant"
Equator
The imaginary great circle around the earth's surface, equidistant from the poles and perpendicular to the earth's axis of rotation. It divides the earth into the Northern Hemisphere and the Southern Hemisphere.
Latitude
The angular distance north or south of the earth's equator, measured in degrees along a meridian, as on a map or globe.
Longitude
Angular distance on the earth's surface, measured east or west from the prime meridian at Greenwich, England, to the meridian passing through a position, expressed in degrees (or hours), minutes, and seconds.
Perigee
The point nearest the earth's center in the orbit of the moon or a satellite.
Period
The time is takes for a satellite to perform one orbit.
Prograde
The usual order or direction.
Retrograde
Opposite to the usual order; inverted or reversed.
Satellite
An object launched to orbit Earth or another celestial body.
Thrust
A Force that acts to accelerate a massive body, such as a rocket engine thrusts the rocket forwards.



© Ryan Murray, Rob Petro, Luc Serré, Yihan Tian, 2006, All Rights Reserved.