The Dark Energy Survey begins five-year mission

From now on, the world's most powerful digital camera will turn its lenses skyward: For the next five years, the 570-megapixel camera of the Dark Energy Survey will provide color images of one-eighth of the sky in unprecedented accuracy. An international team of physicists and astronomers, including members of the Excellence Cluster Universe, will use this remarkable machine to ascertain why the universe is expanding faster and faster. Working from an observatory in Chile, they aim at solving the mystery of Dark Energy, the energy, which is believed to be causing the acceleration.

In 1998, two teams of astronomers studying distant supernovae made the discovery that the expansion of the universe is speeding up. This is contrary to the theory of General Relativity: According to Einstein, gravity should lead to a slowing of the expansion. To explain the new observation, cosmologists have postulated a new form of energy that makes up about three quarters of the universe: Dark Energy, which exhibits a gravitational force opposite to the attractive force of ordinary matter. Alternatively, the General Relativity must be replaced by a new theory of gravity on cosmic scales.

To ascertain why the universe is expanding faster and faster, an international collaboration has started the Dark Energy Survey (DES). One of the founding members is Prof. Dr. Joseph Mohr, astrophysicist from the Faculty of Physics at Ludwig-Maximilians-University, Munich (LMU). The survey’s goal is to find out why the expansion of the universe is speeding up, instead of slowing down, and to probe the mystery of Dark Energy, the energy believed to be causing that acceleration. The main tool of the survey: The Dark Energy Camera, a 570 megapixel digital camera, mounted on a telescope at the Cerro Tololo Inter-American Observatory in the Andes Mountains in Chile. The camera includes five precisely shaped lenses, the largest nearly a meter in diameter. After ten years of planning, construction and testing, the Dark Energy Survey officially started on 31 August 2013. 120 physicists and astronomers will systematically map one-eighth of the sky. Since 2010, the Excellence Cluster Universe is part of the collaboration. "The observations of the Dark Energy Camera will tell us about the fundamental nature of matter, energy, space and time," says astrophysicist Prof. Dr. Jochen Weller from the LMU Faculty of Physics. Just like Prof. Dr. Joseph Mohr, he is a Principal Investigator of the Excellence Cluster Universe and member of the DES collaboration.

The Dark Energy Camera is the most powerful instrument of its kind. With each snapshot, it will be able to see light from more than 100,000 galaxies up to eight billion light years away. The survey’s observations will not be able to visualize Dark Energy directly. However, by studying the expansion of the universe and the growth of large-scale structures over time, the survey will give scientists the most precise measurements to date of the properties of Dark Energy.

Further information
Dark Energy Survey

Interaktive DECam

Contact
Prof. Dr. Jochen Weller
Ludwig-Maximilians-Universität
Universitäts-Sternwarte München
Scheinerstr. 1
81679 München
Tel. +49.89.2180.5976
E-Mail: jochen.weller@usm.uni-muenchen.de

Prof. Dr. Joseph Mohr
Ludwig-Maximilians-Universität
Universitätssternwarte
Scheinerstr. 1
81679 München
Tel.+49.89.2180.6001
E-Mail: jmohr@usm.uni-muenchen.de

Press contact
Excellence Cluster Universe
Petra Riedel
PR Manager
Technische Universität München
Tel. +49.89.35831.7105
E-Mail: petra.riedel@universe-cluster.de