A geomagnetic storm is a major disturbance of Earth's magnetosphere that occurs when there is a very efficient exchange of energy from the solar wind into the space environment surrounding Earth.

How often does a geomagnetic storm happen?

Geomagnetic storms are classified as either "recurrent" or "non-recurrent." Recurrent storms, corresponding with the Sun's rotation, occur every 27 days.

Where do geomagnetic storms come from?

A geomagnetic storm is a temporary disturbance of the Earth's magnetosphere. Associated with solar coronal mass ejections, coronal holes, or solar flares, a geomagnetic storm is caused by a solar wind shock wave which typically strikes the Earth's magnetic field 24 to 36 hours after the event.