A new virtual telescope has been launched by Microsoft, to rival Google Sky. In a similar fashion, users of the free WorldWide Telescope can whiz around a collection of ground- and space-based observatory data.

“Users can see the X-ray view of the sky, zoom into bright radiation clouds, and then cross-fade into the visible light view and discover the cloud remnants of a supernova explosion from a thousand years ago,” says Roy Gould, a researcher at the Harvard-Smithsonian Center for Astrophysics (press release).

This product has been in the works for a while. Way back in 2001, Jim Gray of the Microsoft Bay Area Research Center wrote in Science, “Our goal is to make the Internet act as the world’s best telescope—a World-Wide Telescope.”

Microsoft is releasing the WorldWide Telescope as a tribute to Gray, who went missing while sailing off the coast of California last year (SF Chronicle, Reuters, or see Wired’s definitive piece on the search for Jim Gray).

At the moment I can’t seem to download Microsoft’s new offering so I can’t offer you a direct comparison to Google Sky. I’ll see what our resident space expert thinks and get back to you.

In the meantime, here’s what the NY Times makes of the differences:

The WorldWide Telescope results from careful planning and lengthy development in a research division. It has the richer graphics and it created special software to present the images of spherical space objects with less polar distortion. WorldWide Telescope requires downloading a hefty piece of software, and it runs only on Microsoft Windows.

Google Sky started as a Google “20 percent” project, in which engineers can spend time on anything they choose. Google Earth, where Google Sky began, requires a software download, but its Web-based version, which came out in March, does not. The Google culture encourages engineers to put new things onto the Internet quickly and keep improving them, a philosophy geared to constant evolution instead of finished products.

Image: the great Orion Nebula