A former gold mine in South Dakota has been transformed into a major underground science facility. The Homestake Mine once produced about 41 million ounces of gold and 9 million ounces of silver, but today its tunnels are used to study some of the Universe’s biggest mysteries. Scientists conduct experiments searching for dark matter, neutrinos and rare radioactive decay, while also researching microbes, geology and geothermal energy. Located 4,850 feet underground, the Sanford Underground Research Facility shows how a site once built for mining has found a new purpose in scientific discovery.
