South Dakota Detector Logs Possible Dark Matter Hit

Dark matter was first theorized almost a century ago. Scientists are confident it exists because of its gravitational pull at galactic scales, but it has never been directly detected. Reuters reports ordinary matter — stars, planets, people — accounts for only about 15% of all the matter in the universe.

For the past two years, a collaboration of 250 scientists and engineers from 39 institutions across six countries has been combing through LZ data. The detector uses 10 tons of ultrapure liquid xenon and is tuned to catch a hypothesized dark matter particle called a WIMP — a weakly interacting massive particle.

In that data they found one interaction between a xenon atom and another particle that behaved the way a WIMP is predicted to behave: a collision with the atom's nucleus that transferred a small amount of energy, produced a faint flash of ultraviolet light, and jolted the nucleus forward in what physicists call a nuclear recoil.

On Tuesday, Sept. 1, 2026, lead author Dr. Sam Eriksen of the University of Bristol presented the finding at the TeV Particle Astrophysics conference in Japan. Reuters reports the study has been submitted to the journal Physical Review Letters.