This one of THE COOLEST Freegin space simulator programs i have ever used its basically the whole mapped out universe filled with galaxies and inside a galaxy are billions of stars in which most have planets around them!! this program is amazing
you don't need to install it its run off an executable
here's the link! http://en.spaceengine.org/
the best thing about this program IS ITS FREE! you don't have to pay a dime for it.
be warned though its still in a beta phase and is a bit buggy so it will crash, its not that consistent though which is good
the best part though is when you zoom onto the planets surface there's an actual surface with mountains and such!!!
I will post a picture of this program both with the UI and without it
there is also a user manual on their site on how to use it.