Mysterious Anomaly in Pacific Ocean Hints at Nearby Supernova Explosion

An unexpected deep-sea deposit may be the smoking gun from a nearby star that exploded as a supernova in the relatively recent past.

Earlier this year, a team of scientists in Germany discovered a strange spike in beryllium-10 in the seafloor of the Pacific Ocean. This radioactive isotope forms when cosmic rays strike Earth's atmosphere. From there it falls, sinks and settles on the seafloor, before becoming embedded in the crust.

Since the beryllium-10 rain is fairly constant across the planet, the rocky record should be similarly uniform. But the team found a strange concentration that dated to about 10 million years ago. One plausible explanation is that a supernova went off close to Earth around that time.

Now, a separate team has investigated the idea by looking to the stars. T