Gamma-ray bursts (GRBs) are among the most powerful explosions in the universe, second only to the Big Bang. The majority of these bursts are observed to flash and fade within a few seconds to minutes. But on 2 July 2025, astronomers were alerted to a GRB source that was exhibiting repeating bursts and would end up lasting over seven hours. This event, dubbed GRB 250702B, is the longest gamma-ray burst humans have ever witnessed.