In this game you can explore almost any moon or planet of our solar system and visit remarkable nearby stars and see their location in the Milky Way. But you can also change existing bodies or add new ones and make a solar system of your own. The simulation will then act as a gravity and physics sandbox and recalculate orbits in line with Newton's laws.

Go to: http://store.steampowered.com/ and download STEAM client Click "Install Steam" (from the upper right corner) Install and start application, login with your Account name and Password (create one if you don't have). Please follow these instructions to activate a new retail purchase on Steam: Launch Steam and log into your Steam account. Click the Games Menu. Choose Activate a Product on Steam... Follow the onscreen instructions to complete the process. After successful code verification go to the "LIBRARY" tab and start downloading.