Celestia is a free real-time space simulation that lets you experience our universe in three dimensions. Unlike most planetarium software, Celestia doesn't confine you to the surface of the Earth. You can travel throughout the solar system, to any of over 100,000 stars, or even beyond the galaxy. All travel in Celestia is seamless; the exponential zoom feature lets you explore space across a huge range of scales, from galaxy clusters down to spacecraft only a few meters across. A 'point-and-goto' interface makes it simple to navigate through the universe to the object you want to visit. FREE - I think this is pretty cool!http://www.shatters.net/celestia/http://saltydogfly2.avsim.net/images/avsim_sig.jpg"Ah, the Luftwaffe - the Washington Generals of the History Channel." - Homer Simpson

Hi Ken,Yes, I installed it some time ago and I can echo your impressions whole heartedly. I think, if I remember correctly, it was originally intended as an educational tool and, in many respects, competes well with Orbiter. However, it's far more user friendly, allows much greater freedom of movement and doesn't require the same level of grey matter demanded by Orbiter which, it has to be said, stands in a class of its own. Celestia has certainly earned the right to be a permanent resident on my HD :)Mike

Actually I think it is obviously flawed because I can't travel to the edge of the universe ;-) seriously this is a very entertaining program. You have to download the ultra-hi-res images of earth, mars, jupiter...very beautiful.I wonder if I set it to go back in time 15 billion years will it simulate the Big Kablooie? :-lolhttp://saltydogfly2.avsim.net/images/avsim_sig.jpg"Ah, the Luftwaffe - the Washington Generals of the History Channel." - Homer Simpson

"I wonder if I set it to go back in time 15 billion years will it simulate the Big Kablooie?"...parhaps Einstein was involved with the Beta testing? ;)Mike