How realistic is Sky's new disaster drama Cobra?

The drama gets its name from the real-life Cobra, which is short for “Cabinet Office briefing room A”. This is a council that meets in times of emergency, and the country is certainly facing an unprecedented crisis when Prime Minister Robert Sutherland (Robert Carlyle) convenes Cobra to respond to a potential solar flare.

He's joined by Chief of Staff Anna Marshall (Victoria Hamilton) and Home Secretary Archie Glover-Morgan (David Haig) as well as crisis contingency planner Fraser Walker (Richard Dormer).

Here's what you need to know about the reality behind the six-part series...

What is a solar flare? And what is a geomagnetic storm?

The crisis in Cobra (mild spoiler alert!) kicks off in episode one when the sun emits a massive solar flare in the direction of Earth, accompanied by a "coronal mass ejection" (CME) – i.e. the ejection of plasmas and particles into outer space. This leads to a solar storm (also referred to as a geomagnetic storm) on a serious scale. And that, as the Prime Minister is told by his experts, is Very Bad News.

Here's the basic science: the Sun lets off quite a lot of solar flares, sometimes several a day, but the ones we're watching out for are the big ones.

According to NASA, "Solar flares are a sudden explosion of energy caused by tangling, crossing or reorganising of magnetic field lines near sunspots." These are sometimes (but not always) accompanied by CMEs, which are "huge bubbles of radiation and particles from the Sun. They explode into space at very high speed when the Sun’s magnetic field lines suddenly reorganise."

A solar storm takes place thanks to the the interaction of the Sun's ejection (particles and plasma and HUGE amounts of energy) with Earth's magnetic field. According to the Telegraph, "the amount of energy released by a flare can be equivalent to millions of 100-megaton hydrogen bombs exploding at the same time – ten million times greater than that released by a volcanic eruption."

So what happens on Earth, if the Sun happens to be firing in our direction?

Normally, auroras (like the Northern Lights) are only seen around the Arctic and Antarctic, far North and far South – but during a solar storm they can often be seen at much, much lower latitudes as particles penetrate the upper atmosphere. We see this in Cobra when Anna Marshall (Victoria Hamilton) watches the aurora over London.

More dangerously, a geomagnetic storm can disrupt long-range radio communication and radars and navigation systems (including the Global Navigation Satellite System or GNSS), damage satellites, and knock out terrestrial electric power grids.

That's because flares produce electromagnetic radiation across the electromagnetic spectrum at all wavelengths, affecting all frequencies. In practical terms, this is terrible news for airplanes, submarines and boats.

How realistic is Cobra?

According to writer Ben Richards, quite realistic.

He explained: "We talked a lot to the scientists and there's a big centre near Reading, and they're trying to constantly go, 'Guys, watch out for big particle storm'. I mean, we may have over simplified a bit. The order of events, the particle storm hits planes followed by the plasma... but for me as long as it's broadly true and could happen, I think I'm okay with it. We took a lot of scientific advice.

"And it very definitely is a big big issue for the power supplier because when this stuff rushes into the system, it just blows transformers willy nilly. It's true the National Grid says this wont happen, and it's also true that lots of people say you just don't know it might, which is good enough for me when it comes to TV drama."

What we don't know is whether a storm would cause temporary grid instability, or whether it would actually destroy any high-voltage transformers on the grid.

Richards added: "Nobody really knows. It depends on the size and scale and gravity of the what's called the CME, the pulse that comes towards you. They've done a lot of modelling of what could happen."

In the drama, the Prime Minister immediately faces a dilemma: four super grid transformers need replacing after the storm, and he only has three to give out. Unfortunately for him, these transformers are nothing to joke about: we're talking 170 tons of equipment which is tricky to transport and time-consuming to instal.

Richards said: "We have a few spare transformers, but if you have more transformers blown out than you have spares for – which could easily be the case, and that we do know – then you have potential situations where whole regions, particularly in the coastal areas, could be without power for months. And that is a very serious threat, and it's certainly one that the Home Office... they do plan for it. They plan for major power outage."

To see how severe an event like this could be, let's backtrack a little bit to September 1859 when the first solar flare ever records took place. It's still the most powerful on record; the flare was visible to the naked eye, and the storm created beautiful auroras as far down as Cuba and Hawaii. This "solar superstorm" also wreaked havoc with telegraph systems, giving operators electric shocks and causing small fires.

If that storm happened again in 2020 in a world so reliant on electricity and with far more advanced technology, the consequences would be far more severe. Electrical blackouts would impact us on a massive scale, especially if they went on for days or weeks or months. Just think about the effects on hospitals, and transport, and navigation and business and food supplies! And civil order and security!

There have also been some other serious geomagnetic storms that give us some idea about their potential dangers.

The geomagnetic storm of May 1921 was a major event, burning out fuses and electrical appliances causing and total communications blackouts. There was also a solar storm in 1967 leading to a blackout of polar surveillance radars, which wasn't great in the context of the Cold War; the US military scrambled to prepare for nuclear war until the true cause was revealed.

Then there was the ultra-fast coronal mass ejection in 1972, and one in 1989 which blacked out the power grid of Quebec, and another powerful storm in 2003.

In 2005, satellite-to-ground communications and Global Positioning System (GPS) navigation signals were briefly disrupted by a solar storm, and as scientist Louis J. Lanzerotti told NASA, "I would not have wanted to be on a commercial airplane being guided in for a landing by GPS or on a ship being docked by GPS during that 10 minutes."

We've also recently had a close shave; in 2012, there was a solar storm of similar magnitude to the 1859 one – but thankfully it just managed to pass Earth's orbit without hitting us.

As for whether you can predict a solar storm: it's very, very hard to know in advance when a flare will take place, though the US National Oceanic and Atmospheric Administration does track probabilities based on sunspot activity.

Are Anna and PM Robert Sutherland based on real politicians?

Apparently not! When he started writing the drama in 2014 or so, screenwriter Ben Richards had plenty of material and politicians to use for more general inspiration – but no one specific in mind. So if the characters feel familiar, that's probably because they reflect politicians in general.

"On the one hand you're alert to the idea of tropes, on the other hand tropes exist because politician demonstrably behave in certain ways," he explained.

Victoria Hamilton, who plays Chief of Staff Anna Marshall, said: "There isn't one particular person. I've had this a few times now playing people who really existed, and research is a wonderful thing up to a point, so I did some reading into the people that are the people behind power, and there are several places you can go to for great references for this.

"But actually at the end of the day, you have to bring to life the person who's been written on the page... you have to make that leap of faith and just leap of imagination and just bring the person on the page to life."

And as for Robert Sutherland the Tory Prime Minister being Scottish (Scottish!), Carlyle labelled this "as likely as a unicorn". Based on anyone? "No one in particular," he insisted.

David Haig plays Archie Glover-Morgan, who is also apparently also based on "no one in particular" – though (in our opinion) there are shades of Michael Gove and Boris Johnson about him. Archie is a right-winger, a plotter, a cynical political schemer who is determined to bring down the PM by whatever underhand manoeuvring he can.

Haig said: "What fascinates me about men and women like him are the politicians who mask their seriousness with humour, however deprecating or diminishing that humour might be, there is actually a gravitas sunk a few layers beneath Archie. But his modus vivendi, his way of surviving, is through a sort of piercing humour... it's the mix, the paradoxical mix of serious and facetious."

Cobra aired January-February 2020 on Sky One and NOW TV

Cobra starts on Sunday 4 October at 10/9c on PBS in the US