Carrington Event: The 1859 Solar Storm That Would Collapse the Global Power Grid — and Experts Say We're Not Ready

In September 1859, gold miners in the Colorado Rockies woke up at 1 a.m. and started making breakfast. They thought dawn had come early. It hadn't. The sky was on fire with auroras so bright you could read a newspaper by them.

Simultaneously, telegraph operators across Europe and North America were getting electric shocks from their own machines. Some disconnected their batteries entirely — and the lines kept transmitting, powered by nothing but the charged atmosphere above them. Several telegraph offices caught fire.

This was the Carrington Event — the most powerful geomagnetic storm in recorded history. It struck Earth on September 1–2, 1859. The most sophisticated technology we had was the telegraph. Today, we have 15,968 satellites in orbit, billion-dollar power grids threading every continent, and GPS embedded in everything from ambulances to nuclear submarines. If the Carrington Event happened tomorrow, most of it stops working.

What exactly was the Carrington Event?

The Carrington Event was a coronal mass ejection — a billion-ton cloud of magnetised plasma — that erupted from the Sun at extraordinary velocity. Normal CMEs take 2–3 days to reach Earth. This one arrived in 17.6 hours. That's roughly the difference between a transatlantic flight and a fighter jet intercept.

British astronomer Richard Carrington was at his telescope when it happened. He was sketching sunspots on the morning of September 1 when a brilliant white flash appeared, so intense he ran to find a witness. By the time he returned, it had already faded. He'd just watched the largest solar flare ever recorded by human eyes.

What happened when it struck?

The global telegraph network collapsed. But not the way you'd expect — not from power surges killing the equipment. Operators who unplugged their batteries to protect their machines found the lines still working, carrying current induced purely by the magnetic field overhead. One operator in Boston described sending messages using only "the celestial current."

The auroras were visible from almost every latitude on Earth. Northern lights appeared over Cuba, the Bahamas, Jamaica, Hawaii. Southern lights blazed over Chile and Australia. Telegraph operators in Washington DC reported that the aurora was so bright at midnight that they could read fine print without a lamp.

How powerful was it, scientifically?

Solar flares are classified A, B, C, M, and X — with X being the highest. The most powerful flare ever directly recorded by modern instruments was X28, measured in 2003. Using historical geomagnetic records from 1859, scientists estimate the Carrington Event was equivalent to roughly X45 or greater. That's not just off the high end of the scale. It's the scale ripped off the wall.

What was the Quebec blackout — and why does it matter?

On March 13, 1989, a geomagnetic storm forty times weaker than the Carrington Event hit Earth. The entire province of Quebec's power grid failed in under 90 seconds. Six million people lost electricity. Temperatures were below freezing. The blackout lasted nine hours. High-voltage transformers — machines the size of houses — failed under geomagnetically induced current (GIC), a quiet, slow electrical surge that transformer designers never planned for.

Nine hours without power in a Canadian winter was a crisis. Weeks or months without power, across dozens of countries, at the same time, is a civilisational stress test humanity has never attempted. That's the Carrington scenario.

We nearly found out in 2012

On July 23, 2012, the Sun erupted with a CME that scientists later concluded was Carrington-equivalent in energy. It was travelling directly through Earth's orbital path.

Earth had been there 9 days earlier.

Physicist Daniel Baker at the University of Colorado studied the STEREO-A satellite data afterward and published his conclusion plainly: "Had it hit, we would still be picking up the pieces." A 2013 study by the National Academy of Sciences estimated the damage at $1–2 trillion in the first year alone, with recovery taking four to ten years.

What would actually fail today?

The real vulnerability isn't your phone. Phones are small, modern, and relatively hardened. The vulnerability is everything that powers your phone — and powers hospitals, water treatment, fuel distribution, and communications infrastructure.

• Power grids: GIC-induced transformer failures would cascade across interconnected grids. The US has roughly 2,000 extra-high-voltage transformers. Each takes 12–18 months to manufacture. There are no emergency stockpiles. Once they fail, so does everything downstream.
• GPS: The satellite hardware might survive. But signals passing through a supercharged ionosphere become unusable. Aviation, shipping, precision agriculture, financial trading, and 911 systems all depend on GPS timing and positioning. All of it would degrade within hours.
• Satellites: The 15,968 objects currently tracked in orbit would face intense energetic particle flux. Surface charging can destroy solar panels and fry electronics. Hundreds of satellites in high-radiation orbits could be permanently damaged. Communications, weather forecasting, reconnaissance — all compromised simultaneously.
• Radio communications: High-frequency radio blackouts follow ionospheric disruption — the same backup frequencies that militaries and aircraft use when satellites fail.
• Internet: Fiber-optic cables are radiation-hardened. But every data centre and routing node runs on grid power. No grid, no routing. No routing, no internet.

Is another Carrington Event inevitable?

Statistically, yes — eventually. Studies estimate the probability of a Carrington-level hit in any given decade at between 1% and 12%. Right now, we're at solar maximum — the peak of the Sun's 11-year activity cycle. Solar Cycle 25 reached its peak in 2025, and activity remains elevated through 2026–2027. That makes this the highest-risk window we've been in since 2001.

To be clear: we can observe solar eruptions weeks in advance for slow events, and have roughly 15–60 minutes of warning from the DSCOVR spacecraft at L1 for fast-moving CMEs like Carrington. That's enough time to deliberately switch off sections of the power grid, put satellites into safe mode, and divert aircraft from polar routes. It's not enough time to prevent widespread damage — but it may be enough to prevent the worst of it.

What can we actually do about it?

We can't stop a solar flare. We never will. The Sun doesn't take requests. What we can do is watch, prepare, and respond faster than we currently can.

Prediction has improved dramatically. The physics of how CMEs propagate is now well-modelled. Emergency shutdown protocols exist. But the hard physical problem — what to do with 2,000 transformers that take 18 months each to replace — hasn't been solved by policy documents. It requires stockpiles, hardened replacements, and international coordination that doesn't fully exist yet.

Every satellite orbiting overhead right now — all 15,968 tracked objects — is exposed to whatever the Sun decides to do next. The next Carrington Event won't just darken cities. It will reshape the orbital environment above them in a matter of hours. The auroras will be the most extraordinary light show most people alive have ever seen.

Then the lights will go out.