Biggest solar storm heated Earth's atmosphere, generated largest electrical current
In the air, the threat of higher radiation exposure, as well as communication and navigation losses, forced trans-Atlantic flights to change course.
In Short
- Farms affected lost an average of $17,000 each
- The storm generated the largest electrical currents in Earth’s magnetosphere
- Auroras lit skies worldwide
One year after the most severe geomagnetic storm in two decades struck Earth, NASA scientists continue to unravel its big impacts.
Dubbed the Gannon storm in honour of space weather physicist Jennifer Gannon, the May 10, 2024, event began as a training exercise for US agencies-a simulation that abruptly became real.
“Our hypothetical scenario was interrupted by a very real one,” said Jamie Favors, director of NASA’s Space Weather Program.
Ground and Air Disruptions
The storm triggered cascading effects on Earth’s infrastructure.
In the US Midwest, GPS-guided tractors veered off-course, compounding planting delays from heavy spring rains.
Farms affected lost an average of $17,000 each. Trans-Atlantic flights rerouted to avoid radiation spikes and navigation failures, while power grids faced transformer overheating and tripped high-voltage lines.
Atmospheric Upheaval
The thermosphere, Earth’s upper atmospheric layer, heated to a record 1,150C, causing it to expand and loft heavy nitrogen particles higher.
NASA’s GOLD mission captured this expansion, which increased satellite drag. ICESat-2 entered safe mode, and the CIRBE CubeSat deorbited prematurely. The ionosphere-a critical layer for radio communications-warped into a checkmark shape, creating a temporary equatorial gap.
Magnetosphere and Radiation Belts
The storm generated the largest electrical currents in Earth’s magnetosphere in 20 years, observed by NASA’s MMS and THEMIS-ARTEMIS missions.
Curling waves along coronal mass ejections (CMEs) dumped energy into the magnetosphere, while two new temporary radiation belts formed between the Van Allen belts-a discovery critical for astronaut and spacecraft safety.
Global Auroras and Scientific Insights
Auroras lit skies worldwide, with NASA’s Aurorasaurus project logging 6,000 reports from 55 countries.
In Japan, magenta hues puzzled scientists until imaging revealed the lights originated 600 miles high-200 miles above typical red auroras-due to nitrogen and oxygen mixing in the storm-heated atmosphere.
Though the Gannon storm caused no catastrophes, it shows vulnerabilities in satellite operations, agriculture, and aviation.
“These findings are helping us prepare for the next big storm,” Favors noted. With solar activity peaking in 2025, NASA’s data will refine predictive models, ensuring safer navigation through the Sun’s tempests.