We all know that major storms can wreak havoc, flooding cities and decimating infrastructure. But there’s an even bigger worry than wind and rain: space weather. If a massive solar storm hit us, our technology would be wiped out. The entire planet could go dark.
“We’re much more reliant on technology these days that is vulnerable to space weather than we were in the past,” said Thomas Berger, director of the Space Weather Prediction Center at the National Oceanic and Atmospheric Administration. He told Gizmodo, “If we were hit by an extreme event today, it’d be very difficult to respond.”
A solar storm usually starts with a solar flare — a giant explosion on the surface of the sun that sends energy and particles streaming off into space. Small, C-class flares occur all the time and are too weak to affect the Earth, while mid-sized M-class flares can produce minor radio disruptions. X-class flares, meanwhile, are the largest explosions in the solar system, releasing up to a billion hydrogen bombs worth of energy. These eruptions occur very rarely, but when they do, they’re an epic sight.
One of the most powerful flares measured with modern instruments took place during a solar maximum in 2003. It was so large it maxed out our satellite sensors, which registered an X-28 (28 types larger than an X-1 flare, which itself is 10 times greater than an M1 flare). Here’s what that event looked like:
Despite observing flares for over a century, scientists still aren’t totally sure what causes the Sun to erupt. We do know that flares have a lot to do with disruptions in the Sun’s powerful magnetic field, which oscillates over the course of an 11-ish year solar cycle.
We don’t have a great way of forecasting solar flares, and they hit the Earth too quickly for NOAA to provide airline companies with advance notice (it takes about eight minutes for sunlight to reach us).
“The only thing we can do is issue an alert when we see one,” Berger said. “Airlines are very interested in flare effects on high frequency communications, and if there’s a really large event, they’ll consider grounding flights.”
If you’re not an airline operator, you pretty much get to sit this one out. But don’t forget to check out the amazing images over at NASA’s Solar Dynamics Observatory every now and then.
Coronal Mass Ejections
When the Sun flares up, it sometimes shoots a giant cloud of magnetized plasma off into space. This is called a coronal mass ejection (CME). CMEs are the slowest form of solar weather, taking anywhere from 12 hours to several days to reach the Earth. They’re also by far the most dangerous.
A CME will shoot pretty much straight out from the Sun, and there’s always a good chance that the Earth won’t end up in its path. If a CME is coming straight at us, it’ll first hit NASA’s ACE satellite, located at the L1 Lagrange point roughly a million miles in front of the Earth. If that happens, we’ve got anywhere from 30 minutes to an hour before a cloud of plasma rains down from above, interacting with our planet’s magnetosphere and triggering a geomagnetic storm.
That’s when you start to see effects on the power grid.
“This generates huge electrical currents in upper atmosphere of Earth,” Berger said. “Depending on how conductive the ground is, you can get large currents getting picked up by power stations and fed into the grid.” And that’s bad news, because “our grid isn’t designed for huge amounts of current coming out of the ground.”
Geomagnetic storm strength is measured in “disturbance storm time” or Dst, which essentially describes how hard a CME shakes up Earth’s magnetic field. Ordinary storms, which cause the northern lights to flare up but otherwise don’t impact us, register somewhere in the neighborhood of Dst = -50 nT (nanoTesla). The worst geomagnetic storm of the space age, which knocked out power across Quebec in March of 1989, registered a Dst = -600 nT.
But even that 1989 storm looks puny in comparison to the Carrington event, a geomagnetic storm that zapped the Earth 156 years ago. At the time, the damage wasn’t too bad. But a Carrington-sized storm today could spell disaster.
The Carrington event of September, 1859 is named for Richard Carrington, the English astronomer who saw the sun flare up with his own eyes. In the days following Carrington’s observation, a series of powerful CMEs hit the Earth head-on, igniting the northern lights as far south as Cuba. Currents electrified telegraph lines, shocked technicians, set telegraph papers on fire, and caused widespread communications outages.
Modern estimates for the strength of this storm range from Dst = -800 nT to -1750 nT.
Human society is far more reliant on electricity today than it was 156 years ago. Berger pointed out that today we have pipelines, electrical transmission grids, and a lot more ground-based electrical conduction technology. So, what would happen if a Carrington-sized event struck us now? Pretty much ever [sic] aspect of the modern world would take a hit, according to a report by the National Academies of Sciences.
The ground currents induced by large geomagnetic storms can melt the copper windings of transformers that lie at the heart of power distribution systems. If this happens, it can ;ead tp massive power outages. And because our power grid has grown much more interconnected over time, the effects of such an outage today could be spread far and wide.
It’s hard to overstate just how much this would uproot our lives. The lights would of course go out, as would the internet, and any device that draws current from the wall. In places with electronically-controlled municipal water supplies — like most modern cities — toilets and sewage treatment systems would stop working. Heating and air conditioning would fail. Perishable food and medication would be lost. ATMs would be useless. Gas pumps would go offline. And so forth.
Some of these effects could last years, and they’d be felt globally. “The entire magnetic field of the Earth is changing, so the entire Earth feels it,” said Berger.
It’s hard to fathom the social consequences of billions of power-hungry humans suddenly being pulled off the grid, but I think we can all agree it wouldn’t be pretty. What we do know for sure is that the economic toll would be enormous. The National Academies report estimates that total cost of a Carrington-sized event today could exceed $2 trillion dollars — 20 times greater than the cost of Hurricane Katrina.
It’s important to keep in mind that we aren’t talking about some incredibly far-fetched, Armageddon-style apocalypse situation here. In fact, in July of 2012, a massive CME ripped through Earth’s orbit and narrowly missed us. That event, which was picked up by NASA’s STEREO-A satellite, would have registered a Dst of -1200 nT — comparable to the Carrington event.
“If it had hit, we would still be picking up the pieces,” space weather scientist Daniel Baker of the University of Colorado told NASA in 2014. “How many other [storms] of this scale have just happened to miss Earth and our space detection systems? This is a pressing question that needs answers.”
Are We Dead in the Water?
Thanks to a growing army of space weather observatories, we’re much better able to predict CMEs than we were 20 years ago. Still, most space weather scientists agree that if a massive solar storm struck today, we’d be pretty screwed. But we’re trying to change that.
Full article: What Would Happen if a Massive Solar Storm Hit the Earth? (Gizmodo)