A team of scientists at the University of Virginia is using data from an instrument in Arizona to study cosmic structure and the result is the largest 3D map of the Universe ever created. The Dark Energy Spectroscopic Instrument (DESI) sits on a telescope high above the Sonoran Desert, and is one of the tools of choice to get a handle on the mystery of dark energy by charting the positions of galaxies and other objects. Dark energy is a not-at-all well-understood part of the Universe that appears to be changing over time. How and why and what it is remains a challenge to scientists to explain. For now, they're mapping it as best they can using DESI, and will continue to do so using the Rubin Observatory in Chile, the Euclid mission, and the upcoming Nancy Grace Roman Telescope. The DESI instrument has mapped more than 47 million galaxies as part of its survey, and its work will continue into 2028.…