It took three sky surveys to prepare for a new project that will create the largest 3-D map of the universe’s galaxies and glean new insights about the universe’s accelerating expansion. This Dark Energy Spectroscopic Instrument project will explore this expansion, driven by a mysterious property known as dark energy, in great detail. The surveys, which wrapped up in March, have amassed images of more than 1 billion galaxies and are essential in selecting celestial objects to target with DESI, now under construction in Arizona.
From Berkeley Lab, Dec. 4, 2018: Key components of Berkeley Lab’s Dark Energy Spectroscopic Instrument are installed after months of planning, prep work. A team at Fermilab built the corrector, hexapod, and other top-end support structures. The structures are designed to align the lenses with an accuracy of tens of microns (millionths of a meter) – similar to the width of the thinnest human hair.