Celestia is in fact a great program, for those who are (or not) interested in the outter space. The complete solar system 3d rendered, and you can actually see more than 2.000 stars (and their names).
And the best is, in real time. Which means that you actually can speed up the time and see when will your favorite planet or asteroid be close to Earth.
It also has an application (which works greatly) where you can search for eclipses (in the moon, or in the earth).
It's simply amazing. Try it out, you'll be entertained for hours.
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