New South Pole telescope to explore "dark energy"

Chicago (IL) - Scientists from nine U.S. institutions have began working with a new 280-ton telescope system that may help astronomers to learn more about "dark energy," which is believed to be the cause of the rapid expansion of the universe.

The new telescope, was recently assembled at the South pole and put into operation on February 16. The $19.2 million system, consisting of telescope, camera and optics, is about 75 ft tall and measures 33ft across. Coinciding with the launch of the International Polar Year (IPY), a global research campaign that coordinates 220 research projects, the South Pole telescope (SPT) has been aimed at Jupiter and has completed first test observations, according to the National Science Foundation (NSF), the main financier of the device.

"The telescope, camera and optics are all working as designed," said John Carlstrom, the S. Chandrasekhar distinguished service professor in astronomy and astrophysics at the University of Chicago, who heads the SPT team that tested the scope on Feb. 26. "SPT’s first light is a major milestone for the project and a fitting conclusion to a remarkably productive summer at the South Pole station. We now look forward to fully characterizing the instrument and beginning cosmological observations."

One of the main purposes of the telescope will be to explore dark energy. "We would like to know what makes the universe evolve," said Stephan Meyer, professor in Astronomy & Astrophysics at the University of Chicago. Astrophysicists know that the universe has been expanding since the Big Bang occurred 13.8 billion years ago. In the late 1990s, astronomers using exploding stars as cosmic tape measures discovered that the expansion of the universe is accelerating. This led them to the idea that dark energy pushes the universe apart, overwhelming gravity, the attractive force exerted by all matter in the universe.

Scientists believe that the South Pole location will help them to track down "fingerprints" of dark energy. According to the NSF, the cold and dry Antarctica will allow the SPT to more easily detect the cosmic microwave background (CMB) radiation, the afterglow of the big bang, with minimal interference from water vapor. The first application of the telescope will be to study small variations in the CMB to determine if dark energy began to affect the formation of galaxy clusters by fighting against gravity over the past few billion years.

The NSF said that the SPT can scan large regions of the sky quickly. Scientists expect it to detect thousands, or even tens of thousands, of galaxy clusters within a few years. Also, the CMB allows astronomers to take snapshots of the infant universe, when it was only 400,000 years old. No stars or galaxies had yet formed. If dark energy changed the way the universe expanded, it would have left its "fingerprints" in the way it forced galaxies apart over the deep history of time, the NSF said.

Senior members of the SPT team will include scientists from the University of California at Berkeley and the Lawrence Berkeley National Laborator, University of Illinois at Urbana-Champaign, Case Western Reserve University, Harvard-Smithsonian Astrophysical Observatory, McGill University and NASA’s Jet Propulsion Laboratory.