The Northern Lights are also visible from Emilia (I saw them in Novellara at 11:00 PM). The storm that hit Earth was caused by sunspot AR 3848, which on October 8th produced a strong solar flare of class X 1.8, the most powerful classified. The flare was accompanied by a coronal mass ejection (CME), i.e., plasma material that traveled toward Earth at a speed of between 4.3 and 4.7 million km/h.
