'Great' Space Super Storms Take Place About Once Every 25 Years, Study Finds

Over the last 150 years, "great" space weather super-storms — which can cause significant disruption on Earth — have occurred once every quarter century on average, research suggests.

A team of scientists from the University of Warwick in the U.K. and the British Antarctic Survey analyzed historical data of disturbances in the Earth's magnetic field dating to 1868 to identify space weather patterns.

"We present a novel way of analyzing the data to identify the largest magnetic storms going back some 80 years longer than has been done before," the scientists wrote in a study published in the journal Geophysical Research Letters.

This enabled them to identify the magnetic storms going back some 80 years longer than has been achieved previously. These storms are driven by activity from the sun.

While minor solar storms are common, according to the paper, a "great" super-storm occurred in six years out of 150 (a four percent chance per year.) On the other hand, "severe" magnetic storms—which are less intense—occurred in 42 years out of the last 150 (a 28 percent chance per year.)

Larger solar storms can have a significant impact on Earth, causing disruption to air travel, communications systems, power grids and satellites, among other infrastructure.

"These super-storms are rare events but estimating their chance of occurrence is an important part of planning the level of mitigation needed to protect critical national infrastructure," Sandra Chapman, lead author of the study from Warwick's Centre for Fusion, Space and Astrophysics, said in a statement.

"This research proposes a new method to approach historical data, to provide a better picture of the chance of occurrence of super-storms and what super-storm activity we are likely to see in the future," she said.

solar storm
A solar spot on the sun emitting a flare in 2011. NASA/Solar Dynamics Observatory via Getty Images

The latest study enables researchers to better understand solar storm risk in future by providing a more comprehensive picture of space weather going further back in time, before the dawn of the space age around 1957. Scientists can monitor space weather by looking at changes in the Earth's magnetic field at the surface.

"Our research shows that a super-storm can happen more often than we thought. Don't be misled by the stats, it can happen any time, we simply don't know when and right now we can't predict when," Richard Horne from the British Antarctic Survey said in the statement.

In the study, the researchers also estimated that there was a 0.7 percent chance of a "Carrington class storm" every year. The Carrington storm of 1859 is widely considered to be the largest super-storm ever recorded.

"We are able to give some insight on the Carrington event—a super-storm that occurred before the start of the data that we looked at," Chapman told Newsweek. "Observations of it are very sparse so it is difficult to estimate how large it was, and what kind of damage it could do if it happened today."

"We turned the question around and instead asked: if the Carrington event follows the same statistical distribution as the other superstorms, how large could it have been? We find that it would have been on the upper end of the 'great' storm scale, with a roughly 1:150 year occurrence."

As we rely more on systems that are vulnerable to space weather, the key question for Chapman is what societal impact will these great storms have?

"We can put resources into making our systems more resilient, and quantifying risk and impact—as we are doing in our paper—can assist those tasked with deciding what to invest in resilience planning," she said.

This article was updated to include additional comments from Sandra Chapman.