The distance to Mars

Why not beard seconds?

1) This distance would just be a small fraction of a light year. It's nowhere close to one light year but you can convert kilometers to light years.

1 light years = 9.4605284 × 1012 kilometers

2) The distance is not fixed, and varies widely.

http://www.universetoday.com/guide-to-space/mars/distance-from-earth-to-mars/

Thank you for the link, that was great!

You might like this one then:

Fun with Google Calculator

Light minutes is a better unit for the distance between Mars and earth at any moment.

Let see a AU the distance between earth and the sun is roughly 8 light minutes and the moon is only a few light seconds.

The whole solar system can be measure in units of light hours.