📘 Definition
A Coronal Mass Ejection (CME) is a significant release of plasma and magnetic field from the Sun's corona. CMEs can contain billions of tonnes of material travelling at 250–3,000 km/s. When an Earth-directed CME impacts the magnetosphere, it causes geomagnetic storms that increase atmospheric drag on LEO satellites (the February 2022 storm destroyed 40 Starlink satellites), induce surface charging, degrade GPS signals, disrupt HF radio communications, and potentially damage power grids. CME arrival time from Sun to Earth is typically 15–72 hours.
250–3,000 km/s
Speed
15–72 hours
Travel Time
Billions of tonnes
Mass
Feb 2022 (40 Starlinks lost)
Notable Event