Amazon.com
This software makes learning about the night sky accessible to your entire family. With a few simple steps, you can watch a sunset from the surface of Mars, hitch a ride on a comet, and learn about the stars and planets shining over your house. Or travel through time to marvel at night skies as seen from anywhere on Earth, from the distant past to the far future. It is suitable for both those who own a telescope and those who don't.