Sun activity 20 years ago today! It was November 4, 2003, when the sun produced the largest solar flare of the space age and one of the largest ever observed. The event was off the scale of our instruments. Sun-watchers called them the Halloween Storms.It was the largest flare of the period – even larger than the CarringEvent flare must have been in 1859. (earthsky.org)

                                                                (Image via the EIT telescope aboard SOHO)