In the heart of the Pacific Ocean, among marine sediments that tell the story of our planet, scientists have made a surprising discovery: a previously unobserved radioactive anomaly.

In some samples collected from the depths of the central and northern basins, an anomalous accumulation of beryllium-10, a radioactive isotope normally formed in the atmosphere due to the interaction of cosmic rays with oxygen and nitrogen, has been detected. But what caught the researchers’ attention was the detected quantity: almost twice what was expected. An unexpected discovery.

“This discovery was completely unexpected,” says Dr. Dominik Koll of the Helmholtz-Zentrum Dresden-Rossendorf in Germany, who led the research. “Beryllium-10 is often used to date geological sediments, but in our samples, we found an anomalous peak dating back to the late Miocene. It was not predicted, and now we must understand what caused it.” The study, published in Nature Communications, raises new questions about Earth’s climatic and geological history.

Several hypotheses are under consideration. One possible explanation involves significant changes in ocean currents that occurred between 10 and 12 million years ago, which could have concentrated beryllium-10 in certain marine regions. However, some experts suggest even more intriguing scenarios: it could be the signature of an extraordinary cosmic event.

Supernova Explosion?

The explosion of a nearby supernova or the passage through a dense interstellar cloud could have altered the flow of cosmic rays reaching Earth, increasing the production of this isotope. If this is the case, the beryllium-10 accumulated in the ocean floor could become a key marker for identifying ancient astrophysical phenomena that directly impacted our planet.

To confirm one of these hypotheses, further in-depth analyses will be necessary. If the same anomaly were found in other regions of the world, it could indicate a global phenomenon linked to a cosmic event. If instead, it were confined to the Pacific, a cause related to ocean dynamics would be more likely. In any case, this discovery could serve as a new geological marker, helping to reconstruct Earth’s history with greater precision. While scientists continue their investigations, a new mystery is added to the complex mosaic of our planet’s evolution.