The Extreme Search for Dark Matter: Exploring the Universe a Kilometre Underground

Scientists sometimes need to go to extreme lengths to find answers about the cosmos. This is exemplified by the new Stawell Underground Physics Laboratory (SUPL) located a kilometre underground in regional Victoria. The motivation for SUPL began with the surprising discovery in the 20th century that ordinary matter makes up less than 5% of the mass of the universe. The rest of the universe appears to be made of a mysterious, invisible substance named dark matter (25%), and a force that repels gravity known as dark energy (70%). So far, neither has been directly detected, though physicists know dark matter must exist because of its gravitational effects on galaxies and other astrophysical phenomena. Finding dark matter requires a very sheltered environment deep underground - far from cosmic ray-induced particles - to observe deep space phenomena far below the surface of Earth: this is what SUPL provides. Creating this new underground lab as an extreme project, which now provides the home for the SABRE South experiment: a new detector designed to catch the rare dalliances of these elusive cosmic messengers with ordinary matter. From the depths of a mine shielded from cosmic rays, we will get a glimpse of one of the deepest mysteries of the universe.