Date: 31 Oct 2003
Satellite: SOHO
Depicts: Coronal Mass Ejection
Copyright: SOHO/LASCO (ESA & NASA)

Active region 10486 on the Sun, which was already under close scrutiny by several instruments on board SOHO and other satellites, as well as numerous ground observatories, started up a spectacular two-part show in the morning on Tuesday 28 October 2003.

An X 17.2 flare, the second largest flare observed by SOHO, set off a strong high energy proton event and a fast-moving Coronal Mass Ejection (CME), hitting the Earth early on Wednesday 29 October. The encore came on Wednesday afternoon, when an X 10.0 flare from the same active region set off another round of particles and another fast-moving CME.

These images are from the C3 camera of the Large Angle and Spectrometric Coronagraph (LASCO) on board SOHO. The series of four images shows the first flare on 28 October 2003, with the CME cloud emerging from the Sun and the ensuing shower of energetic particles striking the SOHO instrument. Note: the Sun itself is blocked out in the images, with the size of the Sun's disk indicated by the central white circle.