Massive Camera Begins Survey of 300 Million Galaxies to Help Solve Physics Mystery
The most powerful and highest resolution camera ever built has begun a five-year survey of 300 million galaxies, 100,000 galaxy clusters, and 4,000 supernovae in an effort to better understand dark energy, the little-understood force that is one of greatest mysteries of modern physics.
This massive machine is called the Dark Energy Camera or DECam, and cost over $40 million to develop and construct. It uses 570 million pixels and 62 separate CCDs to capture a massive field of view of 2.2 degrees, allowing each snapshot to cover an area of the night sky equivalent to 20 times the size of the moon as seen from earth, better than any previous camera has been capable of by far. The camera will also be capable of viewing celestial bodies that are up to eight billion light-years away.
The camera was built as part of the Dark Energy Survey, a coalition of astronomers and physicists from the US, the UK, Brazil, Spain, and Germany who hope to better understand the strange force known as dark energy, which accounts for nearly 70% of the known universe, and is believed to be responsible for the increasing expansion of the universe. Scientists on the project hope that this survey will also help us better understand the nature of dark matter, which accounts for over 80% of the universe’s mass.
“This will be the largest galaxy survey of its kind, and the galaxy shapes and positions will tell us a great deal about the nature of the physical process that we call dark energy, but do not currently understand,” Will Percival of the University of Portsmouth said.
It works by examining “redshift,” in which more distant objects appear redder than close ones, which is important in the study of how dark energy is responsible for the universe’s expansion as objects further away are expanding faster than ones that are close by.
“The sensors in this camera were especially designed … to be really excellent sensors of red light,” said Dark Energy Survey Director Joshua Frieman of the University of Chicago. ”The farther away a galaxy is, the redder its color is. The universe is expanding. More distant galaxies are moving away from us more rapidly.”
The camera itself is situated in the Andes in Chile due to the general clarity and lack of adverse weather in the region, and will operate from September until Febraury each year over its five-year run. In that time, Frieman and the other scientists of the Dark Energy Survey hope they will gain a better understanding of how dark energy works, and why.
“We don’t know why the universe is speeding up, and that’s precisely why we’re doing the Dark Energy Survey,” Frieman said. “We’re trying to pin down the nature of dark energy.”