Top End Installation for DESI Project at Mayall Telescope

In this timelapse video, crews at the Mayall Telescope near Tucson, Arizona, lift and install the topend components for the Dark Energy Spectroscopic Instrument, or DESI. The components, which include a stack of six lenses and other structures for positioning and support, weigh about 12 tons. DESI, scheduled to begin its sky survey next year, is designed to produce the largest 3D map of the universe and produce new clues about the nature of dark energy. Full story (Credit: