On May 10, 2024, Earth experienced a major geomagnetic storm, the largest in over two decades, which revealed vulnerabilities in our technological infrastructure. The storm, often referred to as the 'Gannon storm' in memory of space weather physicist Jennifer Gannon, served as a critical reminder of the Sun's capacity to disrupt our lives.
The G5-level storm was triggered by intense activity from a solar region approximately seventeen times wider than Earth. Between May 8 and 11, 2024, this region emitted at least eight coronal mass ejections (CMEs). These CMEs, essentially giant blasts of magnetic field and plasma, reached Earth and caused significant geomagnetic disturbances.
The effects of the storm included disruptions to GPS signals, impacting agriculture, and alterations to transatlantic flight routes due to radiation and communication risks. The storm also caused the Earth's atmosphere to expand, affecting satellites in orbit. However, thanks to early warnings and preparedness, critical infrastructure operators were able to mitigate most of the potential damage.
NASA scientists are still analyzing the data from the Gannon storm to better understand geomagnetic storms and improve our preparedness. The event highlighted the need for continuous monitoring of solar activity and further development of space weather forecasting capabilities.