https://apnews.com/96d884bbef96760b63b9a12ca3bdaee7

LEAD, S.D. (AP) — In a former gold mine a mile underground, inside a titanium tank filled with a rare liquified gas, scientists have begun the search for what so far has been unfindable: dark matter.

Scientists are pretty sure the invisible stuff makes up most of the universe’s mass and say we wouldn't be here without it — but they don't know what it is. The race to solve this enormous mystery has brought one team to the depths under Lead, South Dakota.