The WorldWide Telescope (WWT) is a Web 2.0 visualization software environment that enables your computer to function as a virtual telescopeΓÇöbringing together imagery from the worldΓÇÖs best ground- and space-based telescopes for the exploration of the universe. WWT blends terabytes of images, information, and stories from multiple sources into a seamless, immersive, rich media experience delivered over the Internet. Students of all ages will feel empowered to explore and understand the cosmos using WWTΓÇÖs simple and powerful user interface.
 
http://www.worldwidetelescope.org