Astro*Dictionary
by Michael Erlewine

2 articles for
"Radius Vector"

A line drawn from the focus of an ellipse to an orbiting body; e.g. a line drawn from the Sun to a planet.

Kepler's second law states that even though planets speed up and slow down, the radius vector sweeps over equal areas in equal times.

 

See also: ♦ Kepler's Laws ♦ Ellipse

This is a line which gives the length and bearing ofan arrow of direction from the center of a sphere outwards.

 

See also: ♦ Ellipse