A mysterious accumulation of Beerillium-10a radioactive isotope of Beerillium, was discovered in two areas of thePacific Ocean from a team of German and Australian researchers: its explanation could be geological or climatic, or also astrophysicsdue to cosmic events successes about 10 million years ago.
The study, published in the magazine Nature Communicationsexplains how this anomaly was found in samples of the ocean seabed in the north and in the center of the ocean, dating back to about 10 million years ago. In these samples, the concentration of beryllium-10 is 2 times higher than expected. The most likely causes, according to scientists, are or of terrestrial naturea variation in ocean currents, or astrophysical naturewith an increase in cosmic rays due to the explosion of one supernova. Beerillium, in fact, is produced by interaction of cosmic rays with oxygen and atmospheric nitrogen. To identify the exact cause, scientists intend to analyze multiple samples and encourage other research teams to conduct further studies.
If the anomaly was observed globally, it would strengthen the astrophysical hypothesis. However, if it occurs only in specific regions, the changes in ocean currents would be the most probable explanation. The discovery could help scientists a reconstruct events To which our planet has been meeting in the last 10 million years.
The discovery of the radioactive anomaly: the accumulation of beryllium-10
In the study published in the magazine Nature Communicationsthe researchers of the Helmholtz Center and the University of Dresden in Germany, and the National University of Australia, reported the discovery of a unexpected concentration of beryllium-10 In samples of the ocean seabed of the central and north part of the Pacific Ocean. Beerillium-10 is a radioactive isotope of Beerillium, that is, an atom endowed with the same number of protons as beryllium, but different number of neutrons. Isotopes are often not very stable and radioactive, decaying in other elements, in this case, boronwith a halving time about 1.4 million years.
Beerillium-10 is formed in the atmosphere when i cosmic raysenergy -charged particles, interact with theoxygen el ‘nitrogen In the atmosphere. Once formed, the beryllium-10 reaches the earth’s surface for precipitation Well yes accumulate gradually. Its presence is particularly visible on ocean sedimentssince these are areas a sort of geological archives of the planet, among the most uncontaminated on the globe. From the analysis of the concentration of beryllium-10 and known its halving time, scientists can date the ocean sediments.
Analyzing the samples collected with one mass spectrometeran instrument capable of measuring the abundance of isotopes of a certain element, scientists have noticed that in the seabed layers dating back to 10 million years agothe concentration of beryllium-10 is twice that expectation. To exclude the possibility of contamination, the team examined further samples, which revealed the same anomaly, confirming that it was a real phenomenon.
The possible explanations of the accumulation of Berlin-10 in the Pacific Ocean
Scientists in their article formulated two types of explanations for the unusual accumulation of beryllium-10 in the Pacific Ocean. The first is of terrestrial origin and consists of a drastic change of ocean currents near the Antarctis that took place between 10 and 12 million years ago. This change may have led to a non-uniform distribution of beryllium-10s on the planet, causing an accumulation in the peaceful ocean.
The second type of explanation is instead of astrophysical nature. Scientists speculate in fact that, approximately 10 million years agoa star of mass greater than 8 solar masses may have exploded as supernova at the end of one’s life. This event generates a Large quantity of cosmic raysthat is, electrically loaded with high energy particles. Assuming that the supernova has exploded quite close to the earth, the sudden increase in the flow of cosmic rays could have led to a consequent Increase in the production of beryllium-10 By interaction of the cosmic rays themselves with oxygen and nitrogen in the atmosphere.
Always falling within the explanations of astrophysical nature This is what our million years ago our Solar System would have through one Gas interstellar clouds dense and cold that would have caused a change inheliosphere. The latter is the region of sun influence that helps to protect our planet from the action of cosmic rays coming from outside the solar system. Its reduction can cause an increase in these rays and therefore an increase in the production of beryllium-10 in the atmosphere.
