If you already own Universe Sandbox ², just run Steam to update to the latest version.
Or you can buy Universe Sandbox ² here:
http://universesandbox.com/buy/What's new?We’re unveiling our collision overhaul, which means performance boosts and better collisions more of the time. It also introduces Mars climate simulation, a planetary cutaway view, working orbital elements controls, and an improved graphing tool. We’ve implemented basic tidal heating and tidal evolution, made further improvements to the UI and graphics, and fixed a good number of bugs.
In 13.1, we added some minor performance improvements, made creating a new simulation work better, and we fixed a few more bugs.
Complete List of UpdatesLet us know what you think! And please report any problems either with the in game feedback tool or by starting a new thread...