The Sun is active. It releases light and heat, and sometimes violent storms occur. A strong solar eruption can send charged particles and magnetic fields into space. If one of these hits Earth directly, it can disrupt our planet’s magnetic field and cause a geomagnetic storm. In 1859, the Carrington Event, the largest on record, made telegraph systems spark and created bright auroras far from the poles. Today, a similar storm could damage satellites, disrupt GPS, and even harm power grids. This isn’t science fiction; it is a real risk that governments and space agencies monitor closely.
What causes a solar storm?
Solar storms come in two main types: solar flares and coronal mass ejections (CMEs). A solar flare is a sudden burst of light and energy. A CME releases large clouds of hot plasma and magnetic fields into space. When a fast CME reaches Earth’s magnetosphere, it can cause a geomagnetic storm. This storm indicates how much the magnetosphere is disturbed. Experts use NOAA’s space weather scales to show severity and potential effects. Space weather changes with the Sun’s 11-year cycle, but strong storms can happen anytime a large, active region of sunspots erupts.
What happened in 1859, the Carrington Event
In early September 1859, British astronomer Richard Carrington noticed a huge white flare on the Sun. About 17 hours later, telegraph systems around the world failed. Sparks jumped from equipment, and people saw auroras near the equator. In a world reliant on telegraphs, the effects were dramatic but limited. The lesson was clear: when technology is simple, nature’s fury can still cause problems. Today, our technology is much more complex and vulnerable.
Modern risks, why a Carrington-level storm is worse now
Back in 1859, a storm knocked out telegraphs. Today, we depend on satellites for communication, navigation, weather updates, banking, and emergency services. Power grids use long transmission lines that can pick up geomagnetically induced currents (GICs) during a storm. These currents can overload transformers and cause blackouts. A strong storm could damage high-voltage transformers that take months to replace, leading to long outages across large regions. Satellite electronics and orientation systems can be affected by high radiation, and GPS signals can suffer from ionospheric disturbances. In short, a Carrington-class storm today could cause significant economic harm and disrupt daily life on a massive scale.
How often could this happen?
Large storms like the Carrington Event are rare. Estimates suggest that Carrington-level storms occur roughly once every 500 years, with events about half that strength happening every few decades. However, “rare” does not mean “never,” and smaller yet powerful storms happen more frequently. The Sun is currently in an active cycle, and agencies monitor active regions for warning signs. Scientists agree that the chance of a significant damaging storm in any given solar cycle is not zero, so preparation is important.
What would the worst impacts look like?
A severe geomagnetic storm can produce many effects:
Power grids: GICs can overload transformers, trip protection systems, and cause regional blackouts. Recovery may take weeks or months in damaged areas. NOAA Space Weather Prediction Center
Satellites: Damage to electronics, increased drag on low Earth orbit satellites, and interruption of services like TV, internet, and weather monitoring. NASA Science
Navigation & communications: GPS errors, HF radio blackouts, and degraded mobile services.
Aviation and human health: Increased radiation risk on polar flights; airlines may reroute to avoid exposure.
Pipelines and infrastructure: Induced currents can corrode pipelines faster or disrupt systems that depend on precise timing.
The combined effect could strain emergency services and the economy, especially if power and communications are down for extended periods.
How well can we predict a big solar storm?
We can observe the Sun using satellites like SOHO and SDO and track active regions. If a large CME is directed toward Earth, we typically receive a warning of several hours to a day, depending on the CME’s speed. This allows time to take protective measures, such as putting satellites in safe mode or adjusting power grid settings. However, it’s still challenging to predict the exact strength and impact on Earth. The CME’s magnetic orientation influences how strongly it interacts with Earth’s magnetic field, and we often cannot determine this until the CME arrives. NOAA’s Space Weather Prediction Center and NASA work together to provide warnings and alerts to operators and officials.
Steps to reduce risk. what governments and companies can do
Experts recommend both short-term actions and long-term investments:
Operational warnings: Use NOAA/NASA alerts to prepare satellites, airlines, and grid operators.
Grid hardening: Improve transformer protection, add neutral resistors, and design systems to limit GIC entry.
Spare transformers and rapid replacement plans: Stock critical equipment and ensure logistics for fast repair.
Satellite resilience: Build shields, redundant systems, and safe modes for satellites.
International coordination: Space weather is global — sharing alerts and best practices helps everyone prepare.
Public planning: Emergency plans should include solar storm scenarios, especially for long regional outages.
Some countries run tabletop exercises to test response plans and coordination. These drills help identify weak points and train teams to act fast when warnings arrive.
What individuals can do
You can’t stop the Sun, but you can prepare:
Emergency kit: Keep water, food, medicines, battery radios, and backup power (power banks, solar chargers).
Reduce reliance on GPS: Learn basic maps and keep printed copies of important info.
Protect devices: Use surge protectors and unplug sensitive electronics if warned of a strong event.
Stay informed: Follow NOAA or your country’s space weather services for alerts.
These simple steps reduce personal risk during major outages or communication disruptions.
Recent examples: we have been lucky and had close calls
In recent years, several strong storms have tested our systems. The March 1989 storm knocked out power in Quebec for nine hours. More recently, big storms in 2003 and 2024 to 2025 produced widespread auroras and temporary satellite issues, but they did not cause long-term grid collapse. Each event teaches operators how to respond better next time. Ongoing research helps improve warnings and hardening measures.
In recent years, several strong storms have tested our systems. The March 1989 storm knocked out power in Quebec for nine hours. More recently, big storms in 2003 and 2024 to 2025 produced widespread auroras and temporary satellite issues, but they did not cause long-term grid collapse. Each event teaches operators how to respond better next time. Ongoing research helps improve warnings and hardening measures.
Conclusion
A Carrington-class solar storm could cause serious disruption today, but we have tools to reduce damage. Better forecasting, stronger infrastructure, and clear emergency plans make a big difference. Governments, utilities, and space operators must invest now because recovery from major damage is slow and costly.
We live under an active star. The Sun gives life but can also cause problems. The sensible approach is to respect nature, use the warnings we have, and make our systems more resilient. That way, when the Sun next behaves unpredictably, we will be ready; auroras will be the least of our worries.
