South Pole Telescope to probe 'dark energy'
Published Monday, March 12, 2007 8:55AM EDT
The South Pole Telescope, a 22-metre tall, 280-ton monstrosity housed in one of the coldest places on Earth, has successfully collected its first test observations. And now astrophysicists hope it will shed light on the mysteries of the universe.
Scientists aimed the South Pole Telescope at Jupiter on the evening of Feb. 16 and successfully achieved "first light," the term used to describe the first images a telescope provides.
The scientists on SPT project are hoping to use the instrument to explore the nature of "dark energy," the unexplained phenomenon responsible for the observed acceleration in the expansion of the universe.
Astrophysicists from nine universities are involved in the project, including McGill University's Matt Dobbs. Dobbs says his team will essentially be taking a census of galaxy clusters and using it to trace out the growth history of the universe.
Galaxy clusters are those groups of galaxies that gravity holds together, such as the Milky Way
"We expect to find between 2,000 and 4,000 galaxy clusters that no one else has ever seen before. This telescope is going to provide us with a really new and novel way of looking at the history of universe," Dobbs told Canada AM.
In the late 1990s, astronomers discovered that the expansion of the universe is accelerating. This led to the idea that dark energy pushes the universe apart, overwhelming gravity, the attractive force exerted by all matter in the universe.
By studying cosmic microwave background (CMB) radiation -- at the light left over from the Big Bang -- "we'll be able to learn a lot about the expansion history of the universe - how the universe grew and how it grew to be the way it is today," Dobbs says.
The South Pole telescope is specially created to detect CMB radiation. But in order to detect this radiation, the astrophysicists needed a location where the atmosphere is thin and where the air is dry.
Since the South Pole is one of the driest places on Earth -- drier even than the Sahara Desert -- and the atmosphere is thin, it's about as close to actually being in space as one can get.
"The light we're looking for is not regular optical light or radio light, it's somewhere in between, and its wavelength is 1 mm long, so it has a hard time getting through the atmosphere," Dobbs explained.
The $19.2 million telescope was built in Texas. It was then carefully disassembled and loaded aboard boats and brought down to Antarctica. The final leg of the journey saw the parts being flown into the site.
A team of workers then assembled it starting last polar summer. The SPT team finally tested the scope on Feb. 26 and found that the camera and all the optics were working as designed.
The telescope is funded primarily by the National Science Foundation (NSF), with additional support from the Kavli Foundation of Oxnard, Calif., and the Gordon and Betty Moore Foundation of San Francisco.