GLOBAL: Largest image of sky ever made

Astronomers at the 217th meeting of the American Astronomical Society released the largest digital image of the sky ever made last week. A mosaic created from millions of 2.8 megapixel images recorded over the past decade, the images were produced by the giant Sloan Digital Sky Survey and map the universe in more detail than any others ever achieved.

At the bottom of the picture is a projection of the whole sky as captured by the SDSS telescope in the northern and southern hemispheres. The top left-hand corner is a zoomed image of a small part of the image at the bottom, centered on Galaxy Messier 33 (also known as the Triangulum Galaxy).

SDSS-III, as it is known to astronomers, is a global collaborative effort involving astronomers in dozens of institutions around the globe. Funding for SDSS-III was provided by the Alfred P Sloan Foundation, participating institutions, and the US National Science Foundation and Department of Energy. It is managed by the Astrophysical Research Consortium for the Participating Institutions

The image released last Tuesday is a full-colour representation of the night sky with a resolution of more than a trillion pixels. It is said to be the most comprehensive view of the night sky ever created.

"This image provides opportunities for many new scientific discoveries in the years to come," Bob Nichol, a professor at the University of Portsmouth and a spokesman for the SDSS-III collaboration, said in a statement released at the AAS meeting.

"This image is the culmination of decades of work by hundreds of people and has already produced many incredible discoveries. Astronomy has a rich tradition of making all such data freely available to the public and we hope everyone will enjoy it as much as we have."

The image was created using a 138-megapixel camera attached to a 2.5 metre telescope housed at the Apache Point Observatory in New Mexico. David Weinberg, an Ohio State University astronomer who worked on the SDSS project, told The Guardian newspaper there were a quarter of a billion stars and as many galaxies recorded on the image - a total of more than 500 million celestial objects in total.

In the background of the image available here are hundreds of faint objects, which are distant galaxies and stars. The middle top picture is a further zoom-in on M33, showing the spiral arms of this galaxy including the blue knots of intense star formation known as HII regions.

The top right-hand picture is a further zoom into M33 showing the object NGC604, one of the largest HII region in this galaxy and discovered in 1784 by William Herschel.

Individual images of the northern and southern hemispheres of the SDSS-III image can be found here