| 1 astronomical unit (AU) |
distance between the Sun and Earth |
149,597,870.691 kilometers |
| 1 light second |
distance light travels in one second (in a vacuum) |
300,000 kilometers |
| 1 light year |
distance light travels in one year (in a vacuum) |
9,500,000,000,000 kilometers |
| 1 mile |
|
1.609344 kilometers |
| 1 parsec (pc) |
A parsec is the length of the long leg of a right triangle, whose
short leg is one astronomical unit when the angle between the Sun and
the Earth, as seen from an object in space (a star for example), is one
arcsecond. The word parsec stands for "parallax of one arc second."
 |
3.26 light years |