Solar storms can be even more powerful than what our measurements so far have indicated — and we’re still very unprepared.
Although our planet’s magnetic field keeps us blissfully unaware of it, the Earth is constantly being pelted with cosmic particles. Sometimes, however — during events known as solar storms, caused by explosions on the sun’s surface — this stream of particles turns into a deluge and breaks through that magnetic field.
Research over the last 70 years or so has revealed that these events can threaten the integrity of our technological infrastructure. Electrical grids, various communication infrastructure, satellites, and air traffic can all be floored by such storms. We’ve seen extensive power cuts take place in Quebec, Canada (1989) and Malmö, Sweden (2003) following such events, for example.
Now, new research shows that we’ve underestimated the hazards posed by solar storms — the authors report that we’ve underestimated just how powerful they can become.
‘Tis but a drizzle!
“If that solar storm had occurred today, it could have had severe effects on our high-tech society,” says Raimund Muscheler, professor of geology at Lund University and co-author of the study. “That’s why we must increase society’s protection again solar storms.”
Up to now, researchers have used direct instrumental observations to study solar storms. But the new study reports that these observations likely underestimated how violent the events can become. The paper, led by researchers at Lund University, analyzed ice cores recovered from Greenland to study past solar storms. These cores formed over the last 100,000 years or so, and have captured evidence of storms over that time.
According to the team, the cores recorded a very powerful solar storm occurring in 600 BCE. Also drawing on data recovered from the growth rings of ancient trees, the team pinpointed two further (and powerful) solar storms that took place in 775 and 994 CE.
The result thus showcases that, although rare, massive solar storms are a naturally recurring part of solar activity.
This finding should motivate us to review the possibility that a similar event will take place sooner or later — and we should prepare. Both the Quebec and Malmö incidents show how deeply massive solar storms can impact our technology, and how vulnerable our society is to them today.
“Our research suggests that the risks are currently underestimated. We need to be better prepared,” Muscheler concludes.
The paper “Multiradionuclide evidence for an extreme solar proton event around 2,610 B.P. (∼660 BC)” has been published in the journal Proceedings of the National Academy of Sciences.