Ancient Supernovae May Explain Earth's Mysterious Beryllium-10 Spike

A team of astronomers has traced the Sun’s path through the Milky Way to uncover the origin of a mysterious spike in beryllium-10 on Earth. Geologists had previously found unusually high levels of this isotope in deep Pacific Ocean crusts, sparking questions about its source. Researchers led by Efrem Maconi of the University of Vienna studied the isotope’s unusual presence. Beryllium-10 does not form naturally on Earth but appears when cosmic rays strike the atmosphere, often indicating a violent cosmic event.

The team used data from the Gaia space probe, which has tracked the movements of over 1.8 billion stars. By simulating the trajectories of the Sun and 2,725 open star clusters over 20 million years, they pinpointed a turbulent period for Earth. Between 10 and 11.5 million years ago, our planet passed near the edge of the Radcliffe Wave, a dense region of star-forming gas.

During this time, the Sun came close to several star clusters in the Orion region. One cluster, ASCC 20, approached within about 110 light-years of our solar system. This group contained massive stars that would later explode as supernovae, potentially showering Earth with cosmic rays and producing the beryllium-10 spike. The study connects Earth’s geological record with the Sun’s journey through the galaxy. A supernova at this distance would have been visible but not necessarily harmful to life. The findings demonstrate how celestial events have left lasting traces on our planet.