Scientists have released the largest digital color image of the sky ever made, and it's free to anyone who wants a look.

Researchers with the Sloan Digital Sky Survey-III (SDSS-III) unveiled the image today (Jan. 11) at the 217th meeting of the American Astronomical Society, in Seattle. They had assembled the picture over the last decade from millions of 2.8-megapixel images, creating a color image of more than a trillion pixels. [See the new, huge sky photo]

This terapixel image is so big and detailed that you'd need 500,000 high-definition TVs to view it at its full resolution, the researchers said.

"This image provides opportunities for many new scientific discoveries in the years to come," Bob Nichol, of the University of Portsmouth, said in a statement.

Best view of the sky ever

The new image is at the heart of a flood of new data being released by the SDSS-III collaborators at the AAS meeting, which runs through Jan. 13.

This new data release, along with the previous releases that it built upon, gives astronomers the most comprehensive view of the night sky ever made, the researchers said.

SDSS observations already had been used to discover nearly 500 million astronomical objects, including asteroids, stars, galaxies and distant quasars. The latest, most-precise positions, colors and shapes for all these objects are also being released today, researchers said.

"This is one of the biggest bounties in the history of science," said Mike Blanton of New York University, who is leading the data archive work in SDSS-III. "This data will be a legacy for the ages, as previous ambitious sky surveys like the Palomar Sky Survey of the 1950s are still being used today."

More than a decade of work

The new image got its start in 1998, using what was then the world's largest digital camera: a 138-megapixel imaging detector on the back of a dedicated 2.5-meter telescope at the Apache Point Observatory in New Mexico.

Over the last decade, the Sloan Digital Sky Survey used this instrument to scan a third of the whole sky. Now the imaging camera is being retired to become part of the permanent collection at the Smithsonian Institution, researchers said.

Connie Rockosi of the University of California, Santa Cruz started working on the camera in the 1990s as an undergraduate. "It's been wonderful to see the science results that have come from this camera," Rockosi said. "It's a bittersweet feeling to see this camera retired, because I've been working with it for nearly 20 years."