In 1859, the Earth was hit by the largest solar storm in recent times.
Over the course of a day, our planet was hit by streams of solar particles that short-circuited telegraph systems around the world, and the particles caused the Northern Lights to extend to the Caribbean.
Imagine a cosmic radiation storm about 80 times stronger, lasting for years, hitting our planet today. It will shut down virtually all of our satellites, all of our Internet connections and all of our electrical infrastructure.
These radiation storms are called Miyake events. They collide with Earth about every 1,000 years, and a new one could hit us within a decade.
This is demonstrated by a study of radioactive isotopes in tree rings from the University of Queensland in Australia, the results of which have published in the journal Proceedings of the Royal Society A.
Annual gossip about the rings
The Miyake events are named after the physicist Fusa Miyake, who as early as 2012 found astrophysical data hidden in the annual rings of cedars and pines. These showed that a giant radiation storm had hit the Earth in 774 AD (our era).
More precisely, he found a high concentration of radioactive isotopes in the form of carbon-14 in the annual tree rings.
When high-energy particles hit nitrogen atoms in the upper atmosphere, radioactive carbon-14 is formed, which is the form of carbon that can “live” the longest.
They often find their way into the carbon cycle of plants and therefore old tree rings contain carbon-14 which can tell about radiation events of the past.
Other Miyake events occurred in the years 993 AD and 660, 5259, 5410 and 7176 BC (before our era).
Scientists believe solar flares cause massive storms, but this theory is contested by the new study.
The storm formations are a mystery
The research team behind the new study looked at all available data on the ring. There, they were able to infer the carbon intensity, times and durations to define the events that corresponded to Miyake’s events.
The researchers were surprised that the previously detected Miyake events did not coincide with the large charges of energy ejected from the sun.
In fact, other research has shown that high solar activity increases the solar wind, which helps protect the Earth from cosmic rays.
However, the research team believes that cosmic radiation from outside our solar system may have reached Earth during a time when the sun had almost no sunspots or solar flares to protect against radiation from outside; a so-called solar minimum.
Another alternative is that Miyake’s events have nothing to do with the Sun, but are instead triggered by supernovae or other cosmic events such as highly magnetic neutron stars.
Although the researchers don’t have a definitive answer as to what causes the Miyake events, they found that at least one Miyake event lasted more than a year. There are indications that others have been longer.
This means that the Earth could be in danger of ending up in a cosmic radiation storm that could last for years.
Furthermore, scientists believe there is a one percent chance that a Miyake storm could hit Earth within the next decade.
In a world like ours that depends on electricity, this can have dire consequences. Therefore, we need to investigate how these cosmic ray storms are formed. In this way we can find out how to protect ourselves in the future, the researchers conclude.
