Celestia

Anyone who ever writes for a space setting needs Celestia. This is an open source, free to use, free to change (but need to share your changes) piece of software capable of rendering any known celestial object under any specified parameters. It does this in ways that are beautiful, accurate, easily controlled and comprehended, and beautifully performant on modern hardware.

Just a few clicks apart I was able to produce this view of the earth from moderate lunar orbit (low resolution export):



And a comparative view of Terran and Martian orbits on 2 different time scales, with an ideal trajectory for the protagonists to depart the distant outpost on 2152-07-29 (that's a date), arriving on the Moon on 2152-10-21 just 84 days later (image is squished here, click for full [still low resolution] view):


The distance traveled of ~0.68AU (64,000,000 miles) would require a mean velocity of ~14k/s in this time frame, well within human tolerances and even current technology (the vessel in question is a simple emergency craft as well, so it's not going to be sporting the shiny He-3 fusion drives available elsewhere). A surprisingly short trip, considering that they start out 1.9635AU (16.3299457 light-minutes) apart. Quite fortunate.

Aside from the purely geeky aspects of accessible stellar cartography, this software can serve as a marvelous introduction to any skill and educational level of the much larger universe. Highly recommended.