We know that such situations have been occurring for only a good decade. In 2012, Japanese astronomer Fusa Miyake of Nagoya University reported in the scientific journal Nature that some Japanese cedar rings contain extremely high concentrations of the radioactive carbon isotope C-14.

C-14 is constantly produced in the Earth’s atmosphere by neutrons contained in cosmic rays. Because the C-14 isotope is chemically completely identical to ordinary carbon C-12, it is taken up by animals and plants and incorporated into biomolecules. There is a typical concentration ratio of C-14 to C-12.

A very strong shower of cosmic rays

When a plant dies its metabolism stops, so from that point on the concentration of C-14 decreases as it decays with a half-life of 5,730 years, but the number of stable atoms of C-12 remains constant. The time-varying concentration ratio is used to determine the age of biological materials such as wood.

The age of still-living or freshly cut trees can also be determined by counting annual rings. Miyake discovered significantly increased concentrations of C-14 in the jars in 774. This can only be explained by the exceptionally strong cosmic ray shower that hit Earth during these years.

Since humans and animals did not become extinct by the 8th century, the radiation dose was obviously not high enough to cause fatal biological damage. The same goes for another radiation shower that Miyake was able to identify for the year 993. In the meantime, scientists have identified other “Miyake events” — in 7176 BC, 5410 BC, 5259 BC and 663 BC.

A supernova explosion or solar flare as a possible cause

Possible causes of the Earth’s temporarily intense radiation from space are supernova explosions or strong solar flares in which energy-rich protons are emitted into space. These solar protons and the gamma radiation emitted by supernovae could explain the increase in the concentration of C-14 in tree rings.

Additional measurements on ice cores from Antarctica, where cosmic rays led to high concentrations of radioactive beryllium-10 during the years in question, indicate that at least the Miyake events of 774 and 993 are solar origin.

It is not possible to deduce from the timing of previous Miyake events when the next radiation shower can be expected.but even if the next rain, like the previous ones, were not fatal in the biological sense, civilization would still be in grave danger.

What would happen on our planet if all satellites, computers and all electronic infrastructure suddenly failed due to radiation has been sufficiently described by science fiction authors. It would be an apocalypse. However, no one knows if the next Miyake event will take place tomorrow or in 2,000 years.

See also: Here are the most likely end-of-the-world scenarios. Experts highlighted threats

Miyake events allow precise dating

We cannot predict the future, but the dates of known Miyake rains can be used for scientific purposes. For example, it is only thanks to the event of 993 that we know that Vikings they reached North America exactly in 1021, 471 years before Christopher Columbus.

This precise determination was made by analyzing fir and juniper wood from the L’Anse aux Meadows colony on the coast of Newfoundland in what is now Canada. There are the remains of Viking longhouses, with ship nails and bronze pins also found nearby.

In the wood, scientists from the University of Groningen found rings with higher concentrations of C-14 in 993, associated with the Miyake event. By the time the trees were cut down and the houses built, another 28 annual rings had grown. So, in 2021 – exactly 1,000 years later – the exact date of the arrival of the Vikings has been determined. Such precise dating is not possible with the C-14 method.