The Super Cryogenic Dark Matter Search at SNOLAB has begun collecting its first scientific data deep beneath the ground near Sudbury, Ontario.
The international team is looking for light dark-matter particles, which are thought to leave extremely small signals when they interact with ordinary matter.
The experiment's 24 silicon and germanium crystals are kept colder than outer space and shielded from background radiation. The early phase will help scientists tune the equipment before the full search begins in 2027.
No discovery has been announced yet. But beginning the measurements opens a new window on one of the biggest unanswered questions in physics: what most of the matter in the universe is made of.
