Gravitational-wave detectors have captured their biggest spectacle yet: two gargantuan, rapidly spinning black holes likely forged by earlier smash-ups fused into a 225-solar-mass titan, GW231123. The record-setting blast strains both the sensitivity of LIGO-Virgo-KAGRA and the boundaries of stellar-evolution theory,

The merger wasn’t just the biggest ever, but also an event so rare that it challenges existing models for black hole genesis.

An international team of physicists discovered the largest-ever merger of 2 black holes through a phenomenon known as gravitational waves.