Solar Storms and Their Impact on Earth
Solar activity has been ramping up lately after an extended period of minimal activity, Leonard said. We’ve seen the effects in recent months; coronal mass ejections, or CMEs, caused a stunning display of the northern lights across large parts of the U.S., much farther south than they are usually visible.
“The sun has an 11-year cycle where it goes through maximum and minimum,” Shannon Schmoll, director of the Abrams Planetarium at Michigan State University, told USA TODAY. “This results in the number of sunspots seen on the sun. Sunspots result from areas of the sun that have stronger magnetic fields.”
When the sun’s magnetic field bursts, clouds of highly charged particles are released and can go in any direction, known as a CME. When the particles are headed directly toward Earth, that’s when we have a problem, Leonard said. Because of the way magnetic fields impact electric fields, the changing magnetic field can induce a current in our electrical system so large it could fry transformers and cause a blackout and disrupt our communications and GPS systems.
Historical Context: The Carrington Event
This has happened before, and it threw the telegraph system into disarray. In 1859, a British scientist named Richard Carrington observed an intense brightening of the sun. Though coronal mass ejections weren’t yet understood, modern experts believe the event he saw was the flare that preceded a series of extremely intense CMEs that headed directly for Earth. In the following days, northern lights were seen as far south as Cuba, according to NASA.
At the same time, the telegraph system, or the “Victorian internet,” went on the fritz. Some telegraph offices even caught fire.
“A similar storm today could have a catastrophic effect,” NASA said a decade ago.
More recently, in March 1989, a less severe geomagnetic storm knocked out power for about 6 million people in Montreal for hours. Some parts of the northeastern U.S. and Sweden also lost power.
The Likelihood of an Internet Blackout
How likely is an internet blackout after a solar storm? Like the “big one” earthquake expected to hit California sometime in the future, a solar event so large it could wipe out the internet for an extended time is an inevitability, but still an unlikely one right now, Leonard said.
“It could happen tomorrow or it could be another 200 years,” he said, adding that it’s nearly impossible to predict with certainty.
Some experts believe that based on the sun’s cycles of activity, there’s about a 1% chance a year that a Carrington Event-like storm will happen.
Preparation Strategies
The good news is that any major solar activity that could direct a coronal mass ejection toward Earth would be detectable with some lead time. It could take up to a few days for the charged particles to make their way to Earth’s surface, Leonard said.
During that time, emergency officials could start to prepare the power grid. It’s kind of like what Leonard’s mother used to do when a large thunderstorm that could cause power surges was approaching, he said – she would go around the house unplugging things.
“If we had warning that a huge event was coming our way, you’d effectively see the power grid kind of do what my mom was doing very locally in our house, and that is, you could basically take the power grid offline and save the transformers and save the damage,” Leonard said.
The preparation may plunge people into rolling blackouts, so Leonard said it’s wise to always think about what you would do in an extended time without power.
We now have satellites orbiting the sun that constantly monitor activity that could impact Earth, he said.
“We’re pretty good at knowing when something big has happened on the sun,” Leonard said.