spacetoday.net: Giant solar flare observed

Posted: Wed, Nov 5, 2003, 7:33 AM ET (1233 GMT)
Sun on 2003 November 4 (NOAA)

One of the biggest solar flares ever observed erupted on the Sun Tuesday afternoon, but is not expected to have a major effect on the Earth. The flare was spotted at 2:29 pm EST (1929 GMT) Tuesday from a region of the Sun just rotating out of view from the Earth. Scientists estimated the flare to be at least an X8, but noted it could exceed X20 on the scale of solar flare activity. There have been only two other solar flares exceeding X20 ever observed, in 1989 and 2001. This flare was powerful enough that it temporarily saturated X-ray detectors on GOES weather satellites that monitor the Sun. Because the flare is rotating away from the Earth scientists believe it will have only a modest effect on the Earth. The flare did trigger an "extreme" radio blackout, rated R5 on a 1-to-5 scale.