What is a Solar Storm?

Happening now: solar storm activity

11 May 2024: WASHINGTON (AFP) — The most powerful solar storm in more than two decades struck Earth on Friday, triggering spectacular celestial light shows in skies from Tasmania to Britain — and threatening possible disruptions to satellites and power grids as it persists into the weekend.

The first of several coronal mass ejections (CMEs) — expulsions of plasma and magnetic fields from the Sun — came just after 1600 GMT, according to the National Oceanic and Atmospheric Administration (NOAA)’s Space Weather Prediction Center.

It was later upgraded to an “extreme” geomagnetic storm — the first since the so-called “Halloween Storms” of October 2003 caused blackouts in Sweden and damaged power infrastructure in South Africa. More CMEs are expected to pummel the planet in the coming days.

PIC: Aurora Australis (Southern Lights) over Western Australia, May 2024 (Source: ABC)

What is a solar storm?

We wrote and published the following blog in December 2017, more than six years ago. We are republishing it now, as the Earth is in the midst of the largest solar storm activity in recent history.

The article provides background information to help you understand the nature of solar storms and their possible impact on our planet.

Our blog: December 2017

The current age of technology has left us vulnerable to one of the most unpredictable events that can occur within our solar system. An event that could wreak havoc on the sophisticated and embedded technologies upon which we have become increasingly dependent.

The event is a solar storm. Most of us know this as a resulting phenomena called the Northern Lights, or Aurora Borealis – visible around the north magnetic pole.

When the phenomenon occurs around the south pole it is known as the Southern Lights or Aurora Australis. In most cases the Northern and Southern Lights happen at the same time and are mirror images of each other. The closer a person is to a magnetic pole, the better chance of seeing the Aurora. 

The Aurora is caused when electrically-charged particles released from the Sun enter Earth’s atmosphere, creating dazzling green lights. But the beautiful light show is deceiving, it may even be the portent of something more sinister that could turn our planet into a Mars-like wasteland. 

Ever heard of a Carrington Event?

In 1859 a solar coronal mass ejection (CME) hit Earth’s magnetosphere and induced one of the largest and most damaging geomagnetic storms on records.

The associated “white light flare” was observed by British astronomer Richard Carrington and so have since become known as Carrington Events.

If such a massive 'worse-case' event happened today it would cause widespread disruption and damage to our modern and technology-dependent society so devastating it has been described as a ‘doomsday’ solar storm.

Power grids could be knocked out for months. Radar, mobile networks and GPS receivers would also be severely damaged. Flights, banking, telecommunications would become non-operative.

The cumulative worldwide economic losses could reach up to US$10 trillion dollars, and a full recovery would take several years - with no guarantee of it not happening again. 

According to researchers, there's roughly a 10 percent chance this type of event could occur in the next decade.

In space, things would be much worse. A recent paper estimates potential damage to the 900-plus satellites currently in orbit could cost between US$30 and $70 billion. The same satellites, by the way, are essential to our existence in this high-tech age. 

As it was in 1859 the world was experiencing bizarre solar events, with no real knowledge or prior warning as to what was happening. In late August that year southern auroras were observed as far north as Queensland. On September 1, 1859 Carrington made his observation of a huge solar flare. 

It was estimated that the ensuing CME travelled directly towards Earth, taking just over 17 hours to make the 150 million km journey.     

A CME of less magnitude, by the way, usually takes several days to arrive at Earth, but a severe solar storm could see CMEs impacting Earth in as little as 15 minutes.

Back in 1859, the world had comparatively rudimentary communication technologies. When the event happened, telegraph systems worldwide went haywire. Spark discharges shocked telegraph operators and set the telegraph paper on fire. Even when telegraphers disconnected the batteries powering the lines, aurora-induced electric currents in the wires still allowed messages to be transmitted.

The solar explosion not only produced a surge of visible light but also a mammoth cloud of charged particles and detached magnetic loops—the CME—and hurled that cloud directly toward Earth. When the CME arrived, it crashed into Earth's magnetic field, causing the global bubble of magnetism that surrounds our planet to shake and quiver. Researchers call this a "geomagnetic storm." Rapidly moving fields induced enormous electric currents that surged through telegraph lines and disrupted communications.

Can it happen again?

The answer is yes. And there is very little we can do about it. There was a solar storm in 2012 that was of similar magnitude to that of 1859, but it passed Earth's orbit without striking the planet. We dodged a bullet from the Sun. 

The solar flare shown in the photograph above was recorded Dec. 5, 2006, by the X-ray Imager onboard NOAA's GOES-13 satellite. The flare was so intense, it actually damaged the instrument that took the picture.

In the event of a solar storm, humans in space would be in peril, too.

Spacewalking astronauts might have only minutes after the first flash of light to find shelter from energetic solar particles following close on the heels of those initial photons. Their spacecraft would probably have adequate shielding; the key would be getting inside in time.

NASA and other space agencies around the world have made the study and prediction of flares a high priority. Right now a fleet of spacecraft is monitoring the sun, gathering data on flares big and small that may eventually reveal what triggers the explosions. Not that we could do much about it.

To prevent a catastrophe, scientists have proposed to build a massive ‘magnetic deflector’ in space that would sit between Earth and the Sun, diverting the harmful solar emissions away from our planet. But right now, we are very vulnerable.

Is Mars a vision of what Earth could become?

One disturbing theory suggests that Mars may have had an atmosphere like Earth’s. Mars may seem like a cold, arid wasteland these days, but the Red Planet is thought to have once had a thick atmosphere that could have maintained deep oceans filled with liquid water, and a warmer, potentially habitable climate.

Scientists think Mars lost all of this when its protective magnetic field collapsed billions of years ago, and solar wind – high-energy particles projected from the Sun – has been stripping the Red Planet's atmosphere away ever since.

Learn more

www.spaceweather.com

NWS Space Weather Prediction Centre: www.swpc.noaa.gov

Australian Bureau of Meteorology https://www.sws.bom.gov.au/Geophysical