A new paper by Yuta Notsu from the University of Colorado at Boulder and colleagues should be an ominous warning to a global society now heavily dependent on all kinds of electronics. Using data from the Kepler Space Telescope, the researchers looked at the frequency of superflares—which are 10 to 1 million times more energetic than ordinary solar flares—among different kinds of stars. It had been thought that only young stars experience such powerful electromagnetic storms. But the new research, which is backed up by theoretical estimates, shows that even older stars like our Sun have superflares at an average rate of once every 2,000 to 3,000 years.
One might think: “Oh well, that’s not so bad—we still have time.” Not so. Even a normal solar flare can wreak havoc. The most powerful one observed to date was on September 1, 1859—the so-called Carrington Event, which occurred when a solar coronal mass ejection hit Earth’s magnetosphere and produced beautiful auroras even in tropical places like Hawaii, while also setting telegraph systems on fire.
Back then, of course, there weren’t many electronic systems in use. But a similar storm in July 2012, had it hit Earth (it missed us by just 9 days), would have caused widespread disruptions, blackouts, and damages to the electrical grids that provide our cities with electricity. If anything, those grids have become more vulnerable in the seven years since.
Just imagine if a superflare hit Earth tomorrow: The electronics on all communications satellites would be fried, so say goodbye to Facebook and Twitter, and to GPS navigation in your car and phone. The Internet could be down, or severely impaired, for quite a while. Many people would not even be able to flush their toilets, because water supplies in the larger cities usually rely on electric pumps.
David Darling and I have thought about possible catastrophes that might affect humanity, including the danger that our Sun poses. While a superflare would not produce a “megacatastrophe” that ends humankind, it would surely put the survival of our civilization and technology to the test. It is sobering to realize that our star, which usually nurtures us and makes life possible, also has a dangerous side.
A little over 150 years ago, people could experience a gigantic solar storm and still enjoy the wonderful displays in the night sky. Today it would be a whole different ball game.