The video explores the possibility that Earth experienced a gamma-ray burst (GRB) around 1,200 years ago. GRBs are intense cosmic events that release massive amounts of radiation. Evidence from ancient trees and ice suggests a GRB may have hit Earth in 775, causing isotope anomalies. Alternative explanations like solar flares and supernovae are considered but lack supporting historical records. The video also discusses the potential impact of a GRB today, which could damage technology and the ozone layer. The episode concludes with a call to support SciShow Space.

What potential effects would a gamma-ray burst have on Earth if it occurred today?

Why is it significant that gamma-ray bursts are rare within our galaxy?