Microsoft has released a free public beta of its WorldWide Telescope, which is software that lets both amateur and professional stargazers explore the universe from their PCs. The WorldWide Telescope is a rich Web application that accesses high-resolution images taken by ground- and Earth-orbiting telescopes such as the Hubble Space Telescope, the Chandra X-Ray Observatory Center, and the Spitzer Space Telescope. Read Steven Musil's blog for more details.

The main screen of the Worldwide Telescope contains stars visible to the human eye that are mapped into constellations. You can navigate with your mouse in any direction and zoom in or out with its scroll wheel. Points of interest appear when you mouse over. You can also use the top menu or search to find celestial bodies. Here you can see that the edge of the Big Dipper's cup does indeed point to Polaris or the North Star, which is located at the plus sign