First observed in 1859 by Richard Carrington, solar Coronal Mass Ejection (CME) events, also known as solar storms, cause spectacular aurora displays far away from the poles. In 1859, they also fried telegraph equipment — a new technology at the time — and in some cases, its operators.
Although assumed to be somewhat weaker, similar events since have damaged transformers and other equipment in power grids and along electrified railways, and have played havoc with telephone lines. Recently, there has been renewed attention to the potential threat our very own Sun might pose to modern civilization with another Carrington event.
When. Not if.
One of the last big events was in 1989. The first author of this blog still remembers the sight in the night sky over Germany with slow moving wavy red polar lights — not normally a latitude at which northern lights are observed. The people in Quebec were less lucky — it zapped their power grid, in winter, and left millions in the dark for many hours.
In 1989, the Internet was nascent. Most people hadn’t heard of it, and they certainly didn’t rely on it like we do now. Since then, we have come to depend on the Internet in almost every aspect of our lives. Science has also had another good look at CME events and has come to the conclusion that we don’t know how lucky we are as many CMEs miss us but make for nice science observations, like this recent one.
The Carrington event was the biggest CME to hit us since we started looking but we’ve had a few similarly sized near misses, so the next Carrington-class CME coming our way is more a question of when, not if.
This raises the question, what is vulnerable in our technological world, and what about the Internet in particular? It’s a question people increasingly ask (such as here and here) as we approach the peak of a solar cycle in about 2025, which is considered the Sun’s equivalent of cyclone or typhoon season.
The first thing to note here is that, besides light displays in our skies, solar storms generate electromagnetic activity and can send blasts of charged particles heading towards earth. Charges on the move create magnetic fields and as these fields change, they create currents in electrical conductors exposed to the fields. The longer these conductors are, the more of these unwanted currents are left behind. That’s why power lines, telegraph cables, and overhead wires on electrified railway tracks are particularly susceptible. They all run (or used to run) for dozens of kilometres, sometimes hundreds, in the open across the landscape and in the same direction.
Phone lines and Internet technology such as ADSL/VDSL/xDSL are also susceptible, especially when running on poles above ground. However, they tend to be shorter, typically only a few kilometres from an exchange, so it takes a much stronger solar storm to do any damage here.
Fibre-optic connections aren’t normally affected as fibres don’t interact with charged particles, but their terminal equipment is electrical and therefore susceptible, in principle. That said, any equipment connected to the power grid is, in principle, subject to power surges caused by technical issues and faults, and terrestrial weather events, like lightning strikes.
Fortunately, today’s diverse and complex power grids tend to be more robust against big surges than those of a few decades ago, especially where utilities are liable if their network damages customer equipment. Similarly, most end-user equipment now uses switch-mode power supplies instead of clunky conventional transformers, and often has built-in surge protection circuitry. Miniaturization of electronics has also made conductors within equipment shorter, further reducing the risk of damage. But then again, you can never be sure where ageing, substandard, or under-designed components may lurk so expect some communication equipment to die in a big CME event.
Wireless communication (Wi-Fi, Bluetooth, and similar) has the potential to be affected for the duration of a CME passing by earth, as even minute levels of electromagnetic noise at a receiver can drown out the faint signal of a remote transmitter. This can last for days on end until the event is over.
If your Internet comes from a large and older geostationary satellite, then there may also be a risk of satellite damage, as these satellites lack the protection of the Earth’s atmosphere and magnetic field. Often, they also come with quite large solar panel arrays (with long cables) to supply the necessary power for transmission back to earth — so you don’t need an antenna even larger than the one you’ve got. Depending on how energetic (fast) the charged particles of the CME are, you can also get direct damage to componentry. Think of it as an electronic hailstorm.
This is a lesser problem with smaller satellites in Medium Earth Orbit (MEO) and Low Earth Orbit (LEO), where the Earth’s magnetic field has a higher density and less power is needed for transmission.
That said, space weather is an important consideration in satellite operations, and one of the redeeming features of CMEs is that we get some warning of them, typically about a day or even more. This allows satellite operators to manage satellites in such a way as to minimize the risk of damage.
However, researchers suggest that a Carrington-class CME would likely lead to widespread damage among Geosynchronous Orbit Satellites (GEOSATs). Even the temporary disruption of satellite services carries the potential of serious economic damage from events having to be cancelled, planes unable to fly, and lack of communication preventing people and goods from being in the right place at the right time.
Would such an event destroy the Internet? Probably not. Would it cause serious inconvenience to at least some people on the planet? You bet.
Dr Ulrich Speidel is a senior lecturer in Computer Science at the University of Auckland with research interests in fundamental and applied problems in data communications, information theory, signal processing and information measurement. The APNIC Foundation supported his research through its ISIF Asia grants.
This post was co-authored by Dr Nicholas Rattenbury.
Dr Nicholas Rattenbury is a Senior Lecturer in Physics at the University of Auckland with research interests in astrophysics, space systems and space science. He is a past president of the Royal Astronomical Society of New Zealand, the International Astronomical Union National Organising Committee Chair for New Zealand, the Science Lead for the Auckland Programme for Space Systems, and a member of Te Punaha Atea Auckland Space Institute.
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