Massive solar storm, the last of which happened just over 1,000 years ago.
The Earth is constantly being bombarded by cosmic particles, but sometimes the intensity of this ramps up considerably when a solar storm sweeps past. Solar storms are made up of high-energy particles unleashed from the Sun by explosions on the star’s surface.
Three solar “super-storms” are believed to have occurred in the last 3,000 years, with a very powerful one occurring in 660BCE, followed by two other events in 775CE and 994CE.
The researchers from Lund University drilled samples of ice, or ice cores, to find clues about previous storms. The cores come from Greenland and contain ice formed over the past 100,000 years (approximately).
While the previous storms were largely inconsequential as far as humans are concerned, the 21st-century’s reliance on technology would mean that a similarly intense storm today could be devastating.
It could have a highly destructive effect on power grids, communications, GPS systems and information technology, the scientists warned.
The fast-moving charged particles can quickly wipe out sensitive satellite circuits and cause surges in electricity grids, triggering widespread power cuts.
Two severe solar storms in modern times caused extensive power cuts in Quebec, Canada, in 1989 and Malmo, Sweden, in 2003, but both of these events were dwarfed by a solar storm that occurred in 660BCE.
Professor Raimund Muscheler, from Lund University in Sweden, said: “If that solar storm had occurred today, it could have had severe effects on our high-tech society.
“That’s why we must increase society’s protection against solar storms. Our research suggests that the risks are currently underestimated. We need to be better prepared.”
In 2015, Nasa launched a Sun monitoring satellite designed to give advanced warning against future solar storms.