Stephen Bigelow wrote: > Parsec: a unit of steller distance, equal to about 3.25 light years (3.08 * > 10^16 metres), the distance at which the mean radius of the earth's orbit > subtends an angle of one second of arc. > > I don't understand it either. *s* I always thought it was one second of one degree of arc (of 1 AU). Oh well.. close... Bob