quick facts
What it is: Gamma-ray burst GRB 250702B
Where it is: 8 billion light-years away, in the constellation Scutum
When it was shared: Dec. 8, 2025
A gamma-ray burst (GRB) — the most energetic type of explosion in the universe since the Big Bang — is detected once every day, on average. But what happened on July 2, 2025, was highly unusual: NASA's Fermi Gamma-ray Space Telescope, which has been orbiting Earth since 2008, recorded an unusually long-lived GRB that continued emitting in bursts for more than seven hours.
