A mysterious source showers the Earth with radiation: Who discovered the radiation shower?

Scientists used to think that historical increases in the level of radiation reaching the Earth's surface were due to solar winds.

But this stream of radiation may be coming from a much more powerful and mysterious source, according to a new study published in the peer-reviewed journal Proceedings of the Royal Society A.

"There's some kind of extreme astrophysical phenomenon that we don't understand, and it may actually be a threat to us," said astrophysicist Benjamin Pope of the University of Queensland in Australia.

The scientists behind the study studied the radioactive isotopes known as "carbon 14" in tree rings. These elements reveal the increase in radiation levels that have reached the planet throughout history.

Japanese physicist Fusa Miyake was the first to discover the long-range increases in radiation levels that occur periodically. That's why these increases are known as "Miyake events".

According to Pope, there have been 6 Miyake events in the last 10,000 years. The last of these took place in AD 993.

Until now, these increases were believed to occur during "solar maximum phases" when activity on the Sun increases. But tree rings revealed that the increases occurred outside of the maximal universe as well.

In addition, the fact that some sudden increases took too long created question marks.

"At least two of these incidents, and maybe three, have lasted more than a year," Pope told ABC News.

It's a surprising situation. Because if this is a solar flare, the increase won't last that long.

100 times stronger than solar winds

The radioactive particles emitted by solar flares are called solar wind. These winds sometimes reach Earth and cause disruptions to telecommunications.

The last strong solar wind event to reach the planet occurred in 1859. The event known as the Carrington Incident had severely damaged the communications infrastructure.

On the other hand, scientists state that the cosmic event that led to the Miyake events was 100 times stronger than Carrington's.

What could the mysterious source be?

It was previously suggested that these mysterious events could be caused by gamma-ray bursts, supernovas, and neutron stars near the planet.

"It's really important that we solve this problem. Because even the Carrington Incident was 100 times smaller than these Miyake incidents," Pope said.

On the other hand, Pope says the Sun option is still not out of the question. In fact, the Sun is still the most likely source for these radiation showers.

According to the scientist, the explosions occurring in rapid succession on the Sun may be creating a kind of barrage.

"We really need to understand the seriousness of these events," said physicist Andrew Smith of the research team.