URBANA – The expanding universe is being driven by some kind of force. Scientists call that mystery force dark energy but don't know what it is.
A new, five-year project known as the Dark Energy Survey includes scientists from the University of Illinois and a special camera built at Fermi National Accelerator Laboratory in suburban Chicago, all aimed at providing answers about just what that energy is.
The camera began taking photos last weekend through a telescope at the Cerro Tololo Inter-American Observatory on top of a 7,200-foot desert peak in the Andes Mountains in Chile. Scientists at the University of Illinois are processing those images and other researchers from universities around the world are reviewing them. Roughly 200 scientists will eventually be involved.
Dark energy, U of I research scientist Robert Gruendl said, is "the name for something we don't understand. What the survey is trying to do is characterize the ... acceleration we are seeing so we can place limits on what may be causing it."
Scientists 15 years ago first found that the expansion of the universe is speeding up.
The new survey will cover the Southern Hemisphere, following similar work on the Northern Hemisphere conducted in New Mexico as part of the Sloan Digital Sky Survey.
The project says the camera, with resolution of 570 megapixels, is the largest in the world. It will be used to gather 18,000 images a night, operating for 105 nights a year over the next five years.
The first of those are being processed now, and Gruendl hopes to be able to release the first set of images in about a year.
Other scientists at Illinois will be involved, too. Astronomers at the university will analyze galaxy clusters and physicists will observe supernovae to try to chart the expansion of the universe over time, physics professor Jon Thaler said. The university's National Center for Supercomputing Applications is also involved in processing the raw images into data that scientists can use.
"It's an exciting time in cosmology, when we can use observations of the distant universe to tell us about the fundamental nature of matter, energy, space and time," said Josh Frieman, director of the Dark Energy Survey with the U.S. Department of Energy's Fermi Lab, in a news release.
The U.S. Department of Energy, the National Science Foundation and institutions in Brazil, Germany, Spain, Switzerland and the United Kingdom are paying for the project.
On the web: The Dark Energy Survey: www.darkenergysurvey.org/
Cerro Tololo Inter-American Observatory www.ctio.noao.edu/noao/