A few days ago, millions of tons of super-heated gas shot off from the surface of the sun and hurtled 90 million miles toward Earth.
The eruption, called a coronal mass ejection, wasn't
particularly powerful on the space-weather scale, but when it hit the Earth's
magnetic field it triggered the strongest geomagnetic storm seen for years.
There wasn't much disruption this time—few people probably even knew it
happened—but it served as a reminder the sun has woken from a yearslong
slumber.
While invisible and harmless to anyone on the Earth's
surface, the geomagnetic waves unleashed by solar storms can cripple power
grids, jam radio communications, bathe airline crews in dangerous levels of
radiation and knock critical satellites off kilter. The sun began a new 11-year
cycle last year and as it reaches its peak in 2025 the specter of powerful
space weather creating havoc for humans grows, threatening chaos in a world
that has become ever more reliant on technology since the last big storms hit
17 years ago. A recent study suggested hardening the grid could lead to $27
billion worth of benefits to the U.S. power industry.
"It is still remarkable to me the number of people,
companies, who think space weather is Hollywood fiction," said Caitlin
Durkovich, a special assistant to President Joe Biden and senior director of
resilience and response in the National Security Council, during a talk at a
solar-weather conference last month.
The danger isn't hypothetical. In 2017, a solar storm caused
ham radios to turn to static just as the Category 5 Hurricane Irma was ripping
through the Caribbean. In 2015, solar storms knocked out global positioning
systems in the U.S. Northeast, a particular concern as self-driving cars become
a reality. Airline pilots are at greater risk of developing cataracts when
solar storms hit. Female crew see higher rates of miscarriages.
In March 1989, a solar storm over Quebec caused a
province-wide outage that lasted nine hours, according to Hydro-Quebec's
website. A 2017 paper in the journal of the American Geophysical Union
predicted blackouts caused by severe space weather could strike as much as 66%
of the U.S. population, with economic losses reaching a potential $41.5 billion
a day.
To head off such a catastrophe, President Barack Obama's
administration laid out a strategy to begin raising awareness of the dangers of
massive solar storms and to assess the risks they pose. Last year, President
Donald Trump signed the ProSwift bill into law, which aims to build up
technology to improve forecasting and measurement of space weather events.
There's debate among scientists about how much can be done
to shield vulnerable parts of the planet's infrastructure from the effects of
solar storms. Steps such as using non-magnetic steel in transformers and
installing more surge protectors in the grid could bolster resistance, but in
the end the best defense against catastrophe might be better forecasting.
That would go a long way toward helping utilities prepare
for shortages and making sure there are paths to back up their systems in case
they lose power. In weeks, a new model developed by the University of Michigan
will come online to help improve Earth-bound forecasting.
In the U.K., National Grid is building up its supply of
spare transformers and conducting regular drills to deal with a major space
weather event, said Mark Prouse, deputy director of the Department for
Business, Energy and Industrial Strategy, a ministerial department.
Within the past 15 years, the U.S. and U.K. have built space
weather forecasting centers that deliver daily outlooks on what may be coming
from the sun for airlines, power grids, satellite owners and anyone else
threatened by solar flares. While Earth-bound observers can see explosive
storms erupt on the sun, they can't tell the true nature of the threat—exactly
how potent it is—until the blast reaches a set of satellites 1 million miles
from the planet. At that point, there is only 60 to 90 minutes until it hits
Earth.
"Our ability to understand and predict the solar cycle
is still very limited," said William Murtagh, director of the U.S. Space
Weather Prediction Center.
Just as utilities can prepare for a severe thunderstorm by
staging repair workers nearby, similar precautions could be taken ahead of a
solar storm, according to Mark Olson, the reliability assessment manager for
the North America Electric Reliability Corp., a nonprofit answerable to the
U.S. and Canadian governments.
"You have the potential for very large areas to have
voltage instability," Olson said. "Situational awareness is the key
here, just like in terrestrial weather events."
Solar storms have their roots in an 11-year cycle that
shifts the polarity of the sun's magnetic field. The magnetic forces at work on
the sun get tangled during the process, and can punch out through the surface,
sending the sun's plasma into outer space and potentially triggering storms on
Earth.
The most powerful geomagnetic storm ever recorded resulted
in the 1859 Carrington Event, when telegraph lines electrified, zapping
operators and setting offices ablaze in North America and Europe. If a storm of
that magnitude were to hit today, it would likely cut power to millions if not
billions of people.
"When I first started on this road and was briefed on space weather I raised an eyebrow," said Prouse. "It is much more mainstream and some of the mystification is gone. You can now raise it as a risk and not get laughed at."