Massive Solar Eruptions: Permanent Threat from Space
Does the Blackout from the Geryon's Code series have a real-life prototype?
The cornerstone event in my novel series Geryon’s Code is the Blackout - a mysterious event that disconnected Earth from its former colonies on Mars. For decades, the Martians believed that the disaster was caused by a massive solar storm which reached their planet too. But solar eruptions are a real-life threat that can shake Earth's magnetic field and potentially mess with our satellites, power grids, and GPS systems.
Source: NASA
Scientists measure how bad a solar storm is by using Dst index.
Dst stands for Disturbance Storm Time index. It’s a number — measured in nanoteslas (nT) — that tells us how much Earth’s magnetic field is being disturbed by incoming solar energy. The more negative the number, the more intense the geomagnetic storm.
When a solar storm hits — especially one caused by a coronal mass ejection (CME) — the Earth’s magnetic field gets squished and shaken like a bubble, creating a surge of electric currents in space called the ring current. The Dst index measures how much this current weakens our magnetic shield. And this is how we read it:
0 to -50 nT Mild: Barely noticeable; maybe some satellite drag
-50 to -100 Moderate: Minor issues with radio and GPS
-100 to -250 Strong: Potential for power fluctuations, GPS outages
Below -250 Severe: Widespread disruptions, auroras far from poles
Below -600 Extreme: Major blackouts, satellite failures, global risks
Here are the most dangerous solar eruptions ever recorded in human history. They seem to happen more often than we would want it to happen. It’s probable that older times must have seen even worse events, but they were harder to register.
The Carrington Event – the most powerful one
Date: September 1–2, 1859
Strength: Estimated Dst index of -850 to -1600 nT
Impact: Telegraph systems across Europe and North America failed, with some operators receiving electric shocks. Auroras were visible as far south as the Caribbean and Hawaii.
Significance: The most powerful geomagnetic storm on record; serves as the benchmark for extreme solar events. Could have seriously crippled or even wiped out our tech-reliant civilization.
New York Railroad Storm
Date: May 13–15, 1921
Strength: Estimated Dst around -850 nT
Impact: Fires started in telegraph stations; electrical disturbances affected railroad systems in New York and other parts of the U.S.
Significance: Comparable in strength to the Carrington Event, but less known due to lower global reliance on electrical infrastructure.
Quebec Blackout
Date: March 12–13, 1989
Strength: Dst index ~ -589 nT
Impact: Collapsed the Hydro-Québec power grid, leaving 6 million people without electricity for 9 hours.
Significance: First major solar storm in the modern era, highlighting vulnerabilities in power infrastructure.
Halloween Storms (October–November 2003)
Strength: Dst index ~ -383 nT; X45-class flare estimated (strongest ever recorded flare by modern instruments)
Impact: Satellites and GPS systems malfunctioned; airline routes were altered; auroras visible in Texas and the Mediterranean.
Significance: One of the most significant space weather events of the 21st century.
July 2012 Solar Storm, “Near Miss”
Date: July 23, 2012
Strength: Estimated Carrington-level; Dst potentially -1200 nT
Impact: Missed Earth by about a week’s orbit; would have caused widespread technological disruption had it hit.
Significance: NASA labeled it a "near miss" of a catastrophic event, given the risk of modern reliance on electronics.
I don’t believe in Elon Musk’s good intentions, but before a similar catastrophe strikes Earth again, it wouldn’t hurt to have a “backup airfield” in space. But let’s keep in mind that colonies on the Moon and Mars will need extra protection, as they won’t be protected by the magnetic field.