G4 – Severe geomagnetic storming observed as CME from X9.3 flare impacts Earth

A Coronal Mass Ejection (CME) produced by the X9.3 solar flare on September 6, 2017, reached our planet at 23:04 UTC on September 7, 2017, a full day earlier than it was expected. G3 – Strong geomagnetic storming started 23:25 and increased to G4 – Severe at 23:50…… Read more »