Coronal Mass Ejection

Earth experienced a geomagnetic storm on June 22, 2015 due to the arrival of an Earth-directed coronal mass ejection, or CME, from June 20.

The CME originated at 10:24 p.m. EDT on June 20, 2015. Coronal material exploded from the sun at about 780 miles per second, arriving at Earth at 1:59 p.m. EDT on June 22.

NOAA rated the resulting geomagnetic storm as G4, or severe.

A geomagnetic storm happens when the plasma and magnetic fields in a CME interact with Earth’s magnetic field, disturbing the magnetosphere and allowing stored plasma to flow towards the magnetic poles.

The same active region produced two other CMEs in the past few days, which were pushed along by the faster Earth-directed CME from June 20.