The Looming Solar Threat That No One Talks About
published during a new moon.

Credits: NASA Goddard’s Conceptual Image Lab/Greg Shirah

We would all know if an asteroid was coming. Cosmic doom makes for sexy headlines if the object appears palpable, like a rock or other entity hurtling toward Earth. But there’s a viable threat that doesn’t grace our gadgets with seductive warnings, mostly because it’s less visible — even though we can see the source every day. And that ominous danger is solar flares.


But what are solar flares, anyway?

Over a century ago, Earth was hit with a massive solar storm. A solar astronomer named Richard Carrington was minding his own business and checking out sunspots when he noticed two unusually gigantic beads of white light. When he hailed someone else to come look, the spots had already dissipated.

Then the next day, the space weather reached Earth. People saw bright auroras all over Earth before dawn, including tropical locales like Jamaica and Hawaii. Telegraph systems went berserk and literally shocked operators. It was so bright, you could read outside. That 1859 phenomenon went into history as the Carrington Event.

But what are solar flares, anyway? The bursts are, quite frankly, beautiful, their coils like a space bonfire waiting for some ill-fated marshmallows. But there’s serious power behind the pretty flare. NASA compares their internal forces to a rubber band: When the sun’s interior moves, its magnetic fields contort. And when they jolt back to form, they catapult charged particles into space like a terrifying burp.

Visualizing the sun’s magnetic fields can be a little difficult, so here is a magnetic map:


“Imagine what the consequences might be.”

Then there are even bigger eruptions, like the ones that Carrington saw. Those are named coronal mass ejections (CMEs), and they eject billions of tons of particles traveling at a million miles per hour (or more) in a thin, spread-out creep.

Which is kind of a big deal.

There’s reason to worry: If a Carrington-class flare were to reach our atmosphere now, which could take only a day or three, our communications would be toast. Not only would radio waves be disrupted, which has happened after less powerful flares, a report from National Geographic show that satellite-dependent activities would be at enormous risk — and so would our electrical grid, stored data, air traffic, and military operations, to name a few. In 1989, solar plasma managed to knock out power in the entire province of Quebec. ”We live in a cyber cocoon enveloping the Earth,” one scientist told the reporter. “Imagine what the consequences might be.”

Here’s a visualization of the historic event, for somber fun:

The good news is that CMEs are relatively rare. Researchers have recorded geomagnetic storms for over 160 years, and the Carrington Event was by far the largest. Though flares occur relatively regularly, we’ve had close calls, including a CME near-miss in 2012 and a series of flares in 2014. Had the blasts occurred slightly earlier or later, their trajectories would have been squarely facing Earth.

The sun’s solar cycles last about 11 years. At their peak, our star belches more often as it becomes furiously active. Monitoring flares and related phenomena are at the core of NASA’s Solar Terrestrial Relations Observatory (STEREO) mission, which launched two spacecraft — one behind Earth in its orbit, and one ahead — to image solar storm evolution.

While researchers have met numerous times to discuss the likelihood of a severe solar disruption, the most recent symposium acknowledged the glaring gaps of preparation. The Air Force is expanding its monitoring network, and the Federal Emergency Management Agency revealed it has added space weather to its daily agenda. But one thing is clear: Our technology-laden planet is at serious risk of outages, and even if our infrastructure is protected, our atmosphere is not. Let’s hope the sun stays quiet.