History of Orbit

	Revision 11 . . (edit) November 25, 2001 4:17 am by Bryan Derksen
	Revision 10 . . November 19, 2001 8:13 pm by Karl Palmen [Remove links from Perihelion etc, now redirected to this page]
	Revision 9 . . (edit) October 25, 2001 7:07 pm by Karl Palmen [Correct the English (e.g. Perihelion NOT perihelium)]

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Difference (from prior major revision) (minor diff, author diff)

Added: 5a6

Changed: 9,10c10,11

# The orbit of a planet around the Sun is an ellipse, with the Sun in one of the [focal point]?s of the ellipse. Therefore the orbit lies in a plane, called the orbital plane. The point on the orbit closest to the Sun is called perihelion, the point most distant from the Sun is called aphelion. For the Moon and artificial satellites in orbit around the Earth, these points are called perigee and apogee respectively. # As the planet moves around its orbit for a specific amount of time, the line from Sun to planet sweeps a constant area of the orbital plane, irrespective of which part of its orbit the planet traces during that period of time. This means that the planet moves faster near its perihelion than near its aphelion, because at the smaller distance it needs to trace a greater arc to cover the same area.

# The orbit of a planet around the Sun is an ellipse, with the Sun in one of the [focal point]?s of the ellipse. Therefore the orbit lies in a plane, called the orbital plane. The point on the orbit closest to the Sun is called perihelion, the point most distant from the Sun is called aphelion. For the Moon and artificial satellites in orbit around the Earth, these points are called perigee and apogee respectively. # As the planet moves around its orbit for a specific amount of time, the line from Sun to planet sweeps a constant area of the orbital plane, irrespective of which part of its orbit the planet traces during that period of time. This means that the planet moves faster near its perihelion than near its aphelion, because at the smaller distance it needs to trace a greater arc to cover the same area.

Changed: 19c20

# longitude of the perihelion

# longitude of the perihelion