Users can now tap Google to peruse astrological wonders such as the Crab Nebula, an expanding remnant of a supernova 6,300 light years from earth. Markers within the star photos pull in explanatory text from Wikipedia, the online encyclopedia. Overlays outline constellations such as Leo, illustrate phases of the moon and show how the planets visible from Earth orbit over two months.
Google Sky uses high-resolution imagery from the Space Telescope Science Institute, the Sloan Digital Sky Survey, the Digital Sky Survey Consortium, CalTech's Palomar Observatory, the UK's Astronomy Technology Centre, the Anglo-Australian Observatory as well as NASA's Hubble Space Telescope.
The imagery covers 100 million stars and 200 million galaxies, Google said.
While much space imagery is already available online, Google's goal was to make it more accessible by wrapping it into its Google Earth program, which previously focused on satellite images of earth. The project came out of the Google's engineering team in Pittsburgh, Pennsylvania.
"Zoom in to distant galaxies hundreds of millions of light years away, explore the constellations, see the planets in motion, witness a supernova explosion; it's like having a giant, virtual telescope at your command - your own personal planetarium," wrote Lior Ron, a Google product manager on the Google Earth and Maps team blog.
Using the service requires a new download of Google Earth.
While Google Earth is free for regular users, it also offers a commercial version, Earth Enterprise, that lets businesses attach their own data to satellite imagery and host the information on their own server.
Microsoft sells an enterprise version of its Virtual Earth platform, a mapping and imagery service that enterprises can tie into their own applications.