Ancient starlight that began the long journey to Earth eight billion years ago is now reaching a mountaintop in Chile. The newly constructed Dark Energy Camera (DECam), the most powerful sky-mapping machine ever built, has captured and recorded it for the first time.
This light from distant galaxies may help scientists solve one of the biggest mysteries in physics - why the expansion of the universe is speeding up.
Eight years ago, scientists, engineers, and technicians on three continents began working on the Dark Energy Survey (DES). This collaboration resulted in the extremely sensitive 570-Megapixel digital camera, DECam, now mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory high in the Chilean Andes.
The first pictures of the southern sky were taken by DECam on Sept. 12. Over the next five years, using DECam, the DES will measure the history of the expansion of the universe and the development of large-scale cosmic structures over time.
A simulation of a photo of galaxy clusters taken by DECam. A single camera image captures an area 20 times the size of the moon as seen from Earth. Credit: DES.
Dark energy, a force that has never been directly observed, is one of the biggest mysteries of science today. Researchers in DES hope to see signs of this invisible force that seems to pull the universe apart.
Shedding light on this matter will be a major achievement. Whether discoveries from DES prove the existence of dark matter or unveil some other surprise, the results are sure to be exciting.
"It's going to revolutionize our understanding of the universe," says Brenna Flaugher, project manager and scientist at Fermilab. "When you increase the power of your ability to examine the universe by this much, an order of magnitude or more, you often learn something that you did not expect at all. Whatever we find, it's going to be really cool!"