Scientists have made a possible breakthrough in the hunt for dark matter — observing hints of it during an experiment about a mile (1.6 km) underground in South Dakota — though they stopped short of saying they have finally detected this elusive cosmic component.
The researchers described a particle interaction documented at the Sanford Underground Research Facility — built in a former gold mine in the state’s Black Hills region — that might have involved a hypothesized particle called a WIMP, short for “weakly interacting massive particle.” This is one of the proposed candidates for being a dark matter particle.
Ordinary matter makes up stars, planets, people and everything else we can see. But it represents only about 15% of all the matter in the universe. The rest is thought to be dark matter, which does not emit or reflect light, making it invisible to the human eye and to telescopes. But scientists are confident dark matter exists because of its gravitational effects at galactic scales.