Best view of Big Bang 'echo'

A clear view through the thin polar air

By Dr David Whitehouse BBC News Online science editor

A new telescope at the South Pole has provided fresh evidence that the Universe is accelerating outwards, and is dominated by a mysterious form of matter.

It is compelling that we find, in the ancient history of the Universe, evidence for the same dark energy that observations of supernovae give evidence for more recently

Jeffrey Peterson

The telescope, known as an Arcminute Cosmology Bolometer Array Receiver (Acbar), is part of the solar observatory at the US Amundsen-Scott South Pole Station.

The telescope, looking for subtle variations in the cosmic microwave background (CMB) radiation, has produced the most detailed images of the early Universe ever recorded.

The CMB is radiation given off by the rapidly cooling and expanding Universe about 400,000 years after the Big Bang.

Strange dark matter

The Amundsen-Scott South Pole Station is ideally suited for many areas of astronomy, especially observations of the CMB, due to the lack of interfering water vapour in the thin atmosphere above the station.

Early Universe: The CMB is visible at weak radio wavelengths; the colours denote temperature fluctuations

"Our atmosphere may be essential to life on Earth," says co-investigator John Ruhl, "but we'd love to get rid of it. For our observations, the South Pole is as close as you can get to space while having your feet planted firmly on the ground."

The US National Science Foundation (NSF), who fund the research, said the new data supported the currently favoured model of the Universe "in which 30% of all energy is in the form of strange dark matter that doesn't interact with light."

The NSF added: "Sixty-five percent of the Universe is in an even stranger form of dark energy that appears to be causing the expansion of the Universe to accelerate.

"Only the remaining 5% of the energy in the Universe takes the form of familiar matter like that which makes up planets and stars."

The new images show the "seeds" that developed into the largest structures seen in the Universe today.

Ancient history

"It is amazing how precisely our theories can explain the behaviour of the Universe when we know so little about the dark matter and dark energy that comprise 95% of it," says Acbar scientist William Holzapfel of the University of California.

"It is compelling that we find, in the ancient history of the Universe, evidence for the same dark energy that observations of supernovae give evidence for more recently," says Jeffrey Peterson of Carnegie Mellon University.

Future observations will use a new $16m telescope to be installed at the South Pole.

"With information from that telescope we can really solve how the Universe evolved," says John Carlstrom, a astrophysicist who planned the new and existing South Pole telescopes.

At eight metres (26 feet) in diameter, the unique new telescope will dwarf other telescopes and many structures at Amundsen-Scott South Pole Station.

"If you were hiking to the South Pole, this might be the first thing you'd see," says Carlstrom, a University of Chicago professor.