SOHO records a giant flare on the Sun
3 April 2001Last night at 23:51 Central European Time (21:51 UT, 2 April) the Sun unleashed a major solar flare near its northwestern (upper right-hand) side and the event was well observed by the ESA-NASA SOHO spacecraft. It was classified as an X17 flare, probably the strongest flare since 16 August 1989 when an X20 flare occurred. It was slightly more powerful than the famous 6 March 1989 flare which was related to the disruption of the power grids in Canada. The latest event hurled a coronal mass ejection into space - but apparently not towards the Earth, so the impacts will probably be less severe.
However, a proton event started just before 02:00 CET this morning (midnight UT) releasing highly energetic particles that may affect electronic equipment in space. SOHO's LASCO instrument showed an apparent 'snowstorm' caused by energetic particles crashing into the detector.
The flare occurred in the active region 9393 which includes the gigantic sunspot group that has drifted across the solar disk the last week. This was the largest sunspot group to occur in 10 years - 13 times the surface area of Earth at its largest extent. The active region has produced a series of solar flares and coronal mass ejections during the last week. One of the mass ejections produced a powerful geomagnetic storm that raged for more than 24 hours this weekend, dazzling sky watchers who saw the aurora borealis as far south as Mexico.
We are perhaps lucky that the new giant flare didn't occur over the weekend, when the associated mass ejection and particle storm would almost certainly have been aimed more in our direction.
Dr. Paal Brekke
Dr. Bernhard Fleck