We’re constantly bombarded by things

In general, our Earth is regularly exposed to cosmic rays, which are energetic particles, but its magnetic shield, the magnetosphere, usually deflects them. But when this protective barrier weakens, the Earth becomes vulnerable to the increased penetration of cosmic rays.

Cosmic rays consist primarily of hydrogen nuclei that are thrown into space by powerful cosmic events such as supernova explosions. Normally, the magnetosphere captures these particles, protecting the planet from their effects and also from solar radiation.

But the magnetosphere is not static. magnetic poles may changeand the entire field periodically reverses and weakens in the process. During such events, known as “magnetic field excursions”, the protective strength of the Earth’s magnetic shield decreases, potentially exposing the biosphere to higher levels of cosmic radiation.

Scientists rely on isotope measurements to identify periods of increased cosmic radiation flux. When cosmic rays interact with particles in the atmosphere, they form cosmogenic radionuclides, which accumulate in sedimentary rocks and ice cores over time.

important research

One of the well-documented magnetic field excursions, Laschamps eventIt happened about 41,000 years ago. Researchers from the Potsdam Research Center GFZ in Germany examined the relationship of this event to the density of the Earth’s magnetosphere and the concentration of cosmogenic radionuclides such as beryllium-10.

The analysis showed that the rate of beryllium-10 production during the Lachampi event doubled compared to modern rates and the magnetosphere weakened significantly. This allowed the stream of cosmic rays to enter the atmosphere, leading to an increase in the number of secondary particles.

Scientists are trying to learn more about the interaction and consequences of cosmic rays by reconstructing the Earth’s magnetosphere during the Lacchamp event. The results were presented at the European Geological Union (EGU) General Assembly in 2024.