Celestia is a space simulation programme which allows the user to explore the solar system and beyond through the use of a point and go to navigation system which makes it easy to select a destination and then zoom in on the surfaces of moons, stars, planets and other stellar objects. A list of related sites includes a repository of add-ons called the Celestia Motherlode, as well as lists of resources and guides. Celestia is freely available for download and works on Mac, PC and Linux systems.