The Gannon storm: Earth’s most documented severe geomagnetic event in two decades
On May 10, 2024, a G5-rated solar storm struck Earth, pushing the aurora into unusually low latitudes. While it avoided catastrophic destruction, the event triggered a cascade of disruptions from the ground to the edge of space.
Named the Gannon storm in honor of space weather physicist Jennifer Gannon, this event represented the first G5 or "severe" geomagnetic storm to hit Earth in over twenty years. The storm was uniquely significant not just for its intensity, but because it became the best-documented geomagnetic storm in history. Its impact spanned a wide range of altitudes, affecting Earth's upper atmosphere and near-Earth space.
The physical consequences were measurable and widespread. In the thermosphere, temperatures at an altitude of 100 miles surged past 2,100 degrees Fahrenheit, far exceeding the typical peak of 1,200 degrees Fahrenheit. In the atmosphere, the storm forced trans-Atlantic flights to alter their courses due to risks involving communication losses, navigation disruptions, and increased radiation exposure.
On the ground, the storm's effects were felt in the Midwestern United States, where high-voltage lines tripped and transformers overheated. The disruption extended to precision agriculture; GPS-guided tractors veered off-course, complicating planting efforts already hampered by heavy spring rains. While the event did not cause catastrophic damage, the economic impact on affected farms was notable, with some experiencing average losses of about $17,000.
The timing of the storm was particularly striking. It interrupted a Space Weather Tabletop Exercise, a simulation involving NASA and approximately 30 other U.S. government agencies designed to practice responding to solar threats. Scientists are now analyzing the vast amount of data captured during this historic event to better prepare for the future impacts of solar eruptions, which can potentially decimate satellites and overload electrical grids.
Source: What Happened During the Biggest Geomagnetic Storm in More than 20 Years
