Auroras bring beauty, but could they bring disaster?

Last week I was jealous for first time in a long time. A Boeing 767 was landing at my home airport, Dunedin, ready to board passengers on the “Flight to the Lights”. I had aurora envy!

This flight would be taking 150 avid aurora fans on an 8 hour journey down to the South Pole into the auroral oval, the region where the aurora happens, to get a once in a lifetime opportunity to experience and see the aurora up close. Maybe it’ll be me next year! I’d been gutted for many months that I couldn’t afford to go on this flight, I’ve been photographing aurora for the last 15 years, ever since I saw my first one whilst living in Scotland.

Edinburgh aurora
View of the aurora from Edinburgh Scotland, Photograph by Steve Banks

I’m guessing most people know what the aurora is and some of you might even have seen one. For those not familiar, an aurora is a natural display of light that occurs over the north (northern lights or Aurora Borealis) and south (southern lights or Aurora Australis) poles.

Here is a video taken by Stephen Voss during the Flight to the Lights:

This trip had been the brainchild of astrophysicist and Dunedin’s ‘Otago Museum’ Director, Ian Griffin. An interesting fact about Ian is that he’s worked for NASA, has a degree in Astrophysics, but never observed an aurora until he recently came to live in Dunedin. Once he saw his first, he was hooked like the rest of us. His twitter feed  is non-stop auroras pictures.

You can listen to the interview with Ian Griffin at RadioNZ Our Changing World website – http://www.radionz.co.nz/national/programmes/ourchangingworld/audio/201783074/dark-skies,-happy-aurora-watchers

We are lucky here in NZ that Dunedin is far enough south, only a short drive to get away from the city light pollution, that we get visible aurora regularly. Its far to easy once you are hooked to devote too much time to photographing and observing the aurora. At the start of this week we had a strong aurora, a red alert at the Lancaster Aurora Detector [link] pinged me first. You could see the aurora with the naked eye, no camera needed, its truly mesmerising, some might even see it as a love affair. I watched the lighting show dancing through the night sky and before I knew it, it was 3am in the morning and my camera battery was dead. There were others who kept going for much longer.

Welcome to the Stone Age

But us aurora hunters are not the only ones with a fascination, writers have used aurora events in stories ranging from the complete fantasy of it being a gateway to parallel universes in Philip Pullmans the book “The Northern Lights” to a recent sci-fi apocalyptic series I have just finished reading by M.L. Banner. [https://www.goodreads.com/series/161834-stone-age]

The series starts with Stone Age, the world thrown into desolation by unprecedented geomagnetic storm activity caused by massive solar storms bombarding the earth, these are what cause the light displays of the aurora. More about those later as understanding how they interact with the earth is integral to knowing if what ML Banner described can come true. Read more about the book on Goodreads.

stoenage

In the book, the solar storms are so strong that the aurora is no longer confined to the southern and northern regions of the earth, but can be seen everywhere. Massive geomagnetic storms disrupt all electricity supplies, and technology that relies on electronics, sending the human race back to the stone age with no chance of respite. In the book the earth is subjected to constant massive geomagnetic storms, the sky a permanent green hue, and no chance for our current technology driven civilisation to recover. So could this really happen? Finding the answer to this question is much easier than you might think.

What is a Geomagnetic Storm, Solar Storms and all the other terms associated with Aurora

To understand why we get the lights in the sky and potential to damage electrical systems we need to understand a little bit of physics, how the sun works and how the magnetic fields that protect the earth function.

Here is my explanation of the process in as simple terms as I understand it. The sun has lots and lots of magnetic fields that twist, distort and grow into each other. When this happens we get what is known as sun spots, formed as the magnetic fields push themselves out of the sun’s surface. These can result in coronal mass ejections (CME) where particles of neutron and electrons (parts of atoms) also know as plasma is fired out into space as a solar storm.

The earth also has magnetic fields and these have a similar shape to what you would see around a magnet if you placed iron filings near it, some of you might have done that experiment at school. The iron filings form loops that go from one end of the magnet to the other. In the same way the magnetic fields around the earth loop from the south to the north pole.

Print
On the right the effect a magnet has on iron filings. On the right how the magnetic fields of the earth. The Green arrows show how the particles from the solar storm are drawn towards the poles

If the solar storm encounters the earth, the earths magnetic fields cause most of the solar storm to be deflected around the earth. But a small amount of the plasma is pulled back towards the earth by the magnetic fields, back towards the loops that go to the north and south poles. When the particles enter the upper atmosphere they interact with molecules there and excite them. In particular they excite both oxygen and nitrogen. The oxygen and nitrogen atoms can’t stay excited forever and as they lose this extra energy it is given off as light. Oxygen produces mainly green and red, nitrogen produces blue. These are the main colours of the aurora.

This causes disruption of the magnetic shield around the earth and results in geomagnetic storms producing electricity in the atmosphere.

NASA produced a more in depth movie explaining the process for those wanting to learn more.

If the solar storm is big enough it can overcome the earth’s magnetic shield and the particles can be seen much further away from the poles. These are known as Carrington Events. If the geomagnetic storm produced is large enough then the electricity produce in the atmosphere will interact with metal and electrical components on the ground, with potential to cause damage.

Here is a small excerpt of an interview with Ian Griffin by a student of the Otago University Centre for Science Communication where he talks about the potential damage solar storms can cause:

Carrington Events

What you probably aren’t aware of is that in 1859 one of the largest geomagnetic storms recorded affected the earth, the solar activity that caused this event was observed by English Astronomer Richard C. Carrington. When the solar storm hit the earth it was so powerful that it lit up the sky nearly all the way to the equator. Canadian Miners got up to have their breakfast at 2am thinking the sun was rising, the light in the sky was so bright.

aurora_albert_hall
Artist impression of the effects of a massive solar storm. Steve Banks 2017

In Europe and North America the telegraph system failed and in many areas lines were unusable for weeks, the wires sparking and causing several fires. It was widely reported that many telegraph operators had been electrocuted during the event. Even compasses stopped working worldwide. There’s been further research indicating past events even more strong than that of 1859. The largest occurred in 774 AD and was at least 10 times stronger than 1859. Little is know as it would have had little effect on civilisations at the time. An event like that would have devastating consequences in the modern technological age.

A Near Miss

Whats more concerning is that we have recently had a narrow escape from a Carrington Event of greater magnitude than that of 1859. In 2012 a large solar storm missed the earth by 9 days. It was only reported to the public by NASA in 2014 and received very little publicity. According to research by ML Banner for his book there is a 60% chance of a Carrington level event happening to us within the next 10 years. It was estimated that had that solar storm hit the earth, in the United States alone it would have cost billions of dollars to repair the damaged electrical systems, would have caused nationwide blackouts and rendered electronic devices useless. It could have taken up to 10 years to recover from such an event. It is possible that we could encounter even stronger events that could have a more devastating effect.

This means the “Stone Age” story is based on good sound science. Although significant solar storms might not continue to batter the earths for years as in the book, they do have the real and likely potential to cause the havoc described in the story. Some countries are now looking at ways to shield key electrical systems, so perhaps the effects won’t be quite so extreme.


 

Could you live without technology that surrounds us in our everyday life? Let me know in the comments below.

More information about the event in 774AD can be found here.

Aurora Detection and Alerts at Aurora Watch, Lancaster University.

Aurora Australis Detector and Predictor website.

Twitter feed for Ian Griffin.

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