The universe around us is getting bigger all the time, and the rate of this expansion is picking up--but no one knows why. Some entity, dubbed dark energy, may be pulling the cosmos apart or perhaps the laws of gravity must be modified to explain the acceleration. The Dark Energy Survey (DES) project aims to solve the mystery by observing signs of how quickly the universe has expanded and how much matter has clumped together (resisting this expansion) at different epochs of cosmic history. This photo shows a DES image of the galaxy NGC 1365, which lies 60 million light-years from Earth. Credit: Dark Energy Survey Collaboration
The DES officially begun in 2013, uses the four-meter Victor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile. The survey is now in its third season and is set to run until at least 2018. Credit: NOAO/AURA/NSF
To outfit the roughly 40-year-old Blanco telescope for the survey, scientists mounted a new instrument called the Dark Energy Camera on top of it in 2012. The camera is designed to image about 200 million galaxies as well as thousands of new supernovae over the course of the survey. Both types of observations help trace the history of cosmic expansion. Credit: Dark Energy Survey Collaboration
Here scientists build a prototype of the Dark Energy Camera. The camera's wide field of view allows it to regularly scan about one eighth of the sky as well as to look deep at a few select patches of the heavens. Credit: Fermilab
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Before the Dark Energy Camera could be attached to the Blanco telescope it underwent testing on a simulator at the Fermi National Laboratory in Batavia, Ill. Credit: Fermilab
The Dark Energy Camera is made of 62 light sensors called charge-coupled devices (CCDs), which combine to capture a total of 570 megapixels per image. The instrument is optimized to survey large areas of sky very quickly. Credit: Fermilab
A team member inspects the Dark Energy Camera's largest lens, called the C1 lens, which is one meter wide. The camera uses a system of five lenses, each of a different shape, to correct a wide array of optical aberrations. Credit: UCL
The DES team includes 300 scientists from 25 institutions in the U.S. and U.K., Spain, Brazil, Germany and Switzerland. Here a group of collaborators gathers at a June 2011 meeting in Portsmouth, England. Credit: Dark Energy Survey Collaboration
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This DES image shows the Fornax galaxy cluster. The project studies such clusters to trace how much mass has clumped together throughout cosmic time--a process that would have been hampered by dark energy and/or modified gravity. Credit: Dark Energy Survey Collaboration
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