China's Einstein Probe detected a mysterious cosmic explosion — and scientists have no idea what caused it

China's Einstein Probe has spotted a cosmic explosion from a mysterious source that's unlike anything seen before.

The burst was made up of two X-ray flares, about 200 seconds apart, that likely came from the same object. Their behavior is most consistent with powerful cosmic explosions known as gamma ray bursts — except no gamma rays were detected, scientists reported June 13 in the Monthly Notices of the Royal Astronomical Society.

Launched into low Earth orbit in 2024 by the Chinese Academy of Sciences in collaboration with the European Space Agency, the Einstein Probe is designed to scan the sky for high-energy X-ray emission events. Those events are usually short-lived, but scientists can use the data to perform detailed follow-up studies with other instruments. The Einstein Probe orbits Earth every 96 minutes and can scan almost the entire night sky about every five hours.<...