Stellarium is an OpenGL application that acts as a real-time virtual planetarium, plotting realistic sky views similar to what you can see with your own eyes:

It is available for Linux, Windows and Mac OS X.


On a 20" iMac, edit to read:

version                        = 0.6.2

fullscreen                     = true
screen_w                       = 1680
screen_h                       = 1050
bbp_mode                       = 32
horizontal_offset              = 0
vertical_offset                = 0


...and don't try to change resolution via the GUI.