This is the distance from earth to your destination. To get a distance to a space object from the database, type the first letter or two of the object. For example, typing 'Mo' brings up the distance to the 'Moon'. Typing 'Pr'brings up the distance to Proxima Centauri.

Please note that the distances are approximate. Distances to the planets change all the time depending on the earth's orbit and the planets' orbits, but the database isn't clever enough to know that.

If you leave distance blank, it will be calculated if you enter the observer time and the acceleration of the traveler using this equation:

cvt / (c + sqrt(c^2-v^2))    where
    c = the speed of light
    v = maximum velocity
    t = time elapsed in observer timeframe