A powerful supernova 1.9 billion light-years away caused a gamma ray burst (GRB) known as the BOAT, with scientists estimating such an event occurs once in every 10,000 years.
The BOAT GRB took a chunk out of Earth's upper atmosphere, temporarily destroying the ozone layer, but it repaired itself in minutes.
GRBs in our own galaxy could potentially wipe out Earth's ozone layer for years, causing a devastating extinction event. [ more ]