I used to have Starry Nights Backyard which was superb for having a look at the night sky and all therein. I updated my product by purchasing version 3.1 for Windows and Mac; this was purchased only about 6 months ago. It ran on my old computer under Windows XP, but I had trouble on my computer with Windows 7 and trying to run it on the latest IMac. Making enquiries to the producers 'space com or Imaginova' resulted in them saying that it would not run correctly on the latter machines. I purchased Starry Night Enthusiast after finding that I could not upgrade my Backyard version. What I did not realise that I was also purchasing a DVD of over an hour of movies about space; I only wanted the cd!
However, the Starry Night Enthusiast is excellent and I am very impressed with it. It runs smoothly on both the W7 and IMac. What I was surprised about was the amount of detail available. I noticed small spots cruising across the screen, latched on to one of them and it named which satelite and its orbit; it does this for all which might pass overhead near to your location. It provides me with hours of fun.