Microsoft WorldWide Telescope

Microsoft WorldWide Telescope screenshots

A virtual telescope that lets you browse though the known universe

Alternative downloads

Celestia
1.6.1
FREE
Free space simulator that lets you explore the universe in 3D.
Universe Sandbox
2.2
Create and destroy planets, solar systems, galaxies, or even galaxy clusters.
World Wide Telescope
FREE
Install WWT and start your explorations in space and earth.