Amateur astronomers Tuesday got Internet access to imagery from the best telescopes on earth and in space with a new service launched by Microsoft.

The US software giant's new Worldwide Telescope (www.worldwidetelescope.org) merges cosmic images from some of the world's most advanced telescopes into an online version of the universe available for anyone to explore.

"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," said Harvard-Smithsonian Center for Astrophysics researcher Roy Gould said of the new service.

Worldwide Telescope competes with a star-gazing Sky feature added to Google's free Earth mapping service last year.

Worldwide Telescope combines "terabytes of incredible imagery" with simple software to enable Internet users to study stars, planets and other aspects of the cosmos through lenses of the best telescopes currently in use, Microsoft chairman Bill Gates said in a written release.

"The WorldWide Telescope is a powerful tool for science and education that makes it possible for everyone to explore the universe," Gates said.

"Our hope is that it will inspire young people to explore astronomy and science, and help researchers in their quest to better understand the universe," he said.

"I believe this new creation from Microsoft will have a profound impact on the way we view the universe."

Online visitors can pick telescopes they want to view through, with choices including the Hubble Space Telescope, the Chandra X-Ray Observatory Center, and the Spitzer Space Telescope.

Computer software lets people see where planets were in their orbits, where they are and where they are going as well as overlay wavelengths of light that reveal things hidden from unaided eyes.

"We are proud to release this as a free service to anyone who wants to explore the universe," said Microsoft Next Media Research Group manager Curtis Wong.

"Where is Saturn in the sky, in relation to the moon? Does the Milky Way really have a super massive black hole in the center of the galaxy? With the universe at your fingertips, you can discover the answers for yourself."

Google began offering users telescopic views of the cosmos last year in Google Earth with the addition of Sky, which was enhanced in January and includes astronomy links and lessons.

"We're excited to provide users with rich astronomical imagery and enhanced content that enables them to both learn about what they're seeing above and tell their own stories," Google product manager Lior Ron said at the launch.

"By working with some of the industry's leading experts, we've been able to transform Google Earth into a virtual telescope."

At the time, former US astronaut Sally Ride described Sky as "a very cool feature for anyone who has ever looked up a the sky and wanted to know more."