How a Rare Solar ‘Superflare’ Could Cripple Humanity

Our networked, electrified society makes us uniquely vulnerable to the effects of sudden solar weather

A fairly routine solar storm known as a coronal mass ejection (CME) lifts off the sun on Dec. 2, 2003. This one is nothing compared to what scientists say is possible. Image: NASA/SOHO

Life on Earth wouldn’t be possible without the steady shine of our sun, but every now and again, it flares up, at times so strongly it disrupts cell phone calls, knocks a satellite or two silly, trips a power grid, even in one extreme case, starts fires. But in modern times at least, the sun hasn’t yet erupted in a “superflare” — the kind of colossal cosmic disturbance scientists have detected emanating from sun-like stars elsewhere in the galaxy.

But a new study suggests it could happen here. And the results would be catastrophic.

“Our study shows that superflares are rare events,” says Yuta Notsu, a visiting researcher in the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. “But there is some possibility that we could experience such an event in the next 100 years or so.”

A superflare would be hundreds or even thousands of times stronger than the largest solar flare recorded by modern instruments, Notsu and colleagues note in the Astrophysical Journal. The findings were presented last week at an annual meeting of the American Astronomical Society.

While a superflare would likely be devastating, there is already broad agreement among scientists that a far less powerful solar storm, similar to at least two known to have occurred in recorded history (one that struck Earth, one that missed), would in this era of modern communications cripple technology and potentially even society as a whole.

Proof of concept

Solar storms are common. Here’s how they work:

Sunspots, darker areas of intense magnetic energy on the surface of the sun, behave a bit like a shaken soda bottle, trapping energy until the pressure becomes too much and the cap blows off in an eruption. Instead of a splash of carbonation, a flash of electromagnetic radiation — X-rays and other wavelengths — arrives at the Earth about eight minutes later.

A superflare would be hundreds or even thousands of times stronger than the…