Rahul Srivastava

Dark matter is the invisible scaffolding that keeps galaxies from falling apart. Back in the 1970s, Vera Rubin showed that without it, stars on the outskirts would fly away like a carousel without its bolts. Ever since, scientists have been hunting for the particles that make up dark matter.

In an underground laboratory in South Dakota sits a tank of liquid xenon. It catches rare events: particles pass through the Earth, strike xenon nuclei, and those recoil like billiard balls after a hit. One such recoil was recorded at an energy of 248 keV, and it turned out to be as lonely as a loud bell strike on a quiet night.