Wilson da Silva

Science journalist, feature writer and editor.

Feb 1, 2012
Published on: Cosmos Magazine
1 min read
One of the gigantic solar flares of Ferbuary 2011

A solar superflare may come any day, bringing our modern, hyper-wired world to a standstill. We could easily take precautions to avoid this – so why aren’t we?

By Wilson da Silva

IT’S NOW CLEAR that the solar storm of 1859 was the most powerful in recorded history, and the largest known solar flare. When the next flare erupts – as scientists are now certain it will – that burst will wreak global chaos and likely bring our modern interconnected civilisation to a standstill.

Power surges up and down electrical grids could knock out thousands of transformers, cutting power to many of the world’s biggest cities for weeks or months – and transformers are not easily replaced. Mobile networks would go down, refrigerators would fail, banks and stock markets would have to close, and aircraft would lose access to navigation and GPS.

Why have we not been aware of this danger before now? In a sense, we have; there have been several powerful solar flares in the past century, and they have knocked out power grids, scrambled communications and disrupted satellites. 

What’s changed is that scientists had thought that such events, although punishing, had localised effects. And they thought we’d already seen the worst.

Not so. Only recently, clever detective work helped scientists realise just how powerful the massive superflare of 1859 was. But because it was the first documented sighting of a solar flare, and because our world then had few electrical grids and electronic devices, the cascade of effects that followed were not understood or linked together. 

Telegraph operators reported sparks leaping off their equipment, melting wiring and starting fires, while auroras – usually confined to skies near the poles – danced above Cuba and Hawaii, and as far north as Santiago, Chile.

The 1859 Carrington Event was named after a British astronomer who just happened to be studying sunspots on 1 September 1859 when, at 11.18 am GMT, the flare erupted. Only over the past decade, as scientists have sought to understand the Sun’s more recent history, have they pieced together just how immense was the event.

Such a severe solar storm today could take down telecommunications and power grids across the planet, and leave cities dark for months. “This is not a matter of if, it’s simply a matter of when, and how big,” said Jane Lubchenco, a celebrated U.S. marine ecologist and U.S. Under Secretary of Commerce for Oceans and Atmosphere, who heads the U.S. National Oceanic and Atmospheric Administration.

After an unusually quiet period, the Sun is again ramping up toward a new solar maximum, predicted to peak around 2013. A solar maximum is when the Sun’s stormy activity rises, triggering bigger flares and sunspot outbreaks – part of a roughly 11-year cycle. Interestingly, a similarly quiet period preceded the 1859 event.

On Valentine’s Day 2011, a huge solar flare sent a wave of charged particles toward Earth, followed by coronal mass ejections, or blobs of plasma, that took days to arrive. When they did, they interacted with Earth’s magnetic field to cause geomagnetic storms that wiped out radio communications in the western Pacific and parts of Asia, and forced airlines to re-route polar flights to avoid radio outages.

During the last solar maximum, the modern world wasn’t as dependent on satellites, mobile phones and GPS as it is now. Bank transactions now use GPS signals as highly accurate clocks for time-stamping transactions: knock out GPS and the banking system and stock markets go with it.

The good news is that this is a disaster we can avoid. We can’t stop the Sun from flaring – nothing can halt a fusion reactor pouring out 386 billion billion megawatts of energy – but we can shut down our electrical grids and disconnect electronic devices before the pulse arrives, allowing the geomagnetic storm to pass before turning it back on.

It sounds simple, but the problem is knowing exactly when such a superflare is coming. All that sits between us and a superflare is the Advance Composition Explorer (ACE) satellite, orbiting about 1.5 million km from Earth and 148.5 million km from the Sun, at the L1 Lagrange point where the gravitational fields of the two bodies cancel each other out.

With its prime view of the high-energy particles and solar wind spewed out by the Sun toward Earth, ACE can give 15 to 45 minutes advance warning of severe geomagnetic storms. Launched in August 1997, the ACE was judged to be “well beyond its planned operational life” by the U.S. National Academy of Sciences in 2009. As we go into another solar maximum, there is no back-up.

There is a clear case for another satellite – or even a string of them – to be sent up, before calamity strikes. As former U.S. president John F. Kennedy once said, “The time to repair the roof is when the Sun is shining.”