When the Sun Reminds Us Who’s in Charge
We’ve come to rely on satellites for almost everything: directions, banking, weather, communications.
But all of it rests on a quiet assumption - that the Sun will behave itself.
History suggests that’s a risky bet.
Yesterday we unpacked the basics of satellites and space weather. Today, we go a step further: into one of the biggest vulnerabilities facing our modern world: what happens if the Sun doesn’t play along.
Because it hasn’t always.
Some readers might remember discussions about a “Grand Solar Minimum” - a quieter Sun over decades. But quiet doesn’t mean harmless. The Sun doesn’t switch off. It only changes its rhythm. And even during quieter periods, it can still produce sudden, powerful outbursts.
For a world that now depends on thousands of satellites moving in tight formation, it only takes one.
The 1859 Warning Shot
In 1859, during the Carrington Event, British astronomer Richard Carrington observed a massive solar flare. Seventeen hours later, the resulting coronal mass ejection slammed into Earth.
What followed was extraordinary.
Auroras lit the sky as far south as the Caribbean. Telegraph operators received electric shocks. Some lines sparked and caught fire. Messages were transmitted even after power was disconnected - the storm itself energised the wires.
That was a world running on copper.
Ours runs on orbit.
A Crowded Sky Built on Assumptions
Low-Earth orbit used to be mostly empty - a quiet frontier above the atmosphere.
Not anymore.
Since the early 2020s, companies like SpaceX have launched thousands of satellites as part of mega-constellations such as Starlink. What was once open space is now something closer to a busy highway.
And like any highway, it only works if everything keeps moving as expected.
A recent Princeton-led study introduced a new way of thinking about this risk: the CRASH Clock - Collision Realisation and Significant Harm.
Its findings are sobering.
If satellites lose the ability to manoeuvre, a catastrophic collision could occur in just 2.8 days. That figure used to be measured in months. Today, it’s measured in hours and days.
Even a 24-hour loss of control carries roughly a 30% chance of a major collision - the kind that could trigger the feared cascade known as Kessler syndrome, where debris creates more debris until entire orbital bands become unusable.
It’s a bit like building a crowded motorway in the sky… and assuming every driver will always have working brakes, steering, and headlights.
If those systems fail - even briefly - it doesn’t take long before the first crash.
And at orbital speeds, it’s not a fender bender. Not a bingle. It’s shrapnel.
When Space Weather Turns Hostile
Solar storms are perfectly capable of causing exactly that kind of failure.
In late 2025, the European Space Agency ran one of its most extreme simulations: a full Carrington-scale event impacting modern satellites.
The scenario wasn’t subtle. It came in three waves: an initial radiation blast, high-energy particle bombardment, and then the full force of a coronal mass ejection.
The results were not fun.
Earth’s upper atmosphere would swell dramatically, increasing drag on satellites by up to 400% in some regions. Orbits would decay. Electronics would be disrupted or destroyed. Solar panels would degrade.
The conclusion was hard to ignore: in an event of that magnitude, no spacecraft in low-Earth orbit could be truly safe.
We’ve Already Seen the Edges of It
This isn’t theoretical.
In February 2022, a relatively modest geomagnetic storm knocked out around 40 newly launched Starlink satellites before they could even reach stable orbit.
In May 2024, the strongest storm in decades forced widespread satellite manoeuvres, disrupted services, and dramatically increased atmospheric drag.
Other smaller events have already caused premature re-entries.
None of these were anywhere near Carrington-level. They were reminders.
It’s Not Just Satellites
A major solar storm wouldn’t stop at orbit.
It would ripple downward.
Power grids could suffer widespread outages. GPS systems could fail or degrade. Aviation and shipping would be disrupted. Emergency services could lose coordination. Astronauts and high-altitude flights would face increased radiation exposure.
And then there’s the human side.
Modern societies don’t respond calmly to sudden, unexplained disruption. Risk assessments point to the likelihood of panic buying and unrest if systems go dark without warning.
How Likely Is It?
Estimates vary, but many experts place the probability of a Carrington-scale event at roughly 12% per century.
Not frequent. But not rare either.
We are also currently near the peak of Solar Cycle 25, which has already produced a surge in powerful solar flares.
In other words, we are not in a quiet period.
Can We Prepare?
There has been progress.
Satellite operators now monitor space weather more closely. Some spacecraft can enter protective “safe modes.” Governments are investing in improved forecasting systems.
But there’s a catch.
The sheer number of satellites now in orbit - many built with commercial, off-the-shelf components rather than hardened systems - means the network as a whole remains fragile.
We’ve built an orbital infrastructure that assumes constant control.
The Real Question
The real issue isn’t whether we can build better satellites.
It’s whether we’ve quietly built a system that only works when nothing goes wrong.
Because the Sun doesn’t care about our assumptions.
And if it decides to remind us who’s in charge, it won’t happen gradually. It will happen all at once.
My father ran power stations, and I remember those enormous transformers - solid, humming, almost reassuring in their presence. At the time, I never gave them much thought. They were just part of the landscape.
But they sit at the heart of everything. Quietly stepping power up, stepping it down, keeping the system balanced.
And like so much of what we rely on, they work beautifully… right up until something pushes them beyond their limits.
There’s something fitting about that. Satellites may be the glamorous part of our story - the motorway in the sky. But transformers are the ground-level equivalent. Big, solid, dependable. And just as exposed, in their own way, to a star 150 million kilometres away.
We build our modern world on the assumption that the quiet will continue. As a kid, I knew that the quiet never stayed forever. One good electrical storm could bring the whole thing crashing down.
But we believe all will be good. That satellites will stay up. That grids will stay steady. That the Sun will behave itself out of politeness.
But the Carrington Event is not a theory. It is a recorded reminder that none of that is guaranteed.
And if something similar arrived today, the issue would not be whether we understand it - but whether we have built anything resilient enough to survive it.
We often talk about resilience as though it is a technical detail. In reality, it is a design choice. A budget decision. A matter of priorities made long before anything goes wrong.
And that leads us, inevitably, to a slightly uncomfortable question:
Whose bright idea is this?
Because somewhere between our reliance on fragile systems and our assumption that they will always work, we quietly accepted a world where almost everything depends on something we do not control at all.
And the Sun, as it turns out, has never been asked for its opinion on the matter.
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