05 Apr 2001

This latest event hurled a coronal mass ejection into space at an impressive 72 million km/hr. Fortunately Earth was not directly in the line-of-fire so the impacts will probably be less severe than from the previous giant flares.

The flare occurred in the active region 9393 which includes the gigantic sunspot group that has drifted across the solar disk during 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.

Flare-related events also generated a storm of high-velocity particles that, in greater numbers and energies, can affect sensitive electronic equipment in space. The number of particles with ten million electron-volts of energy in the space near Earth is now 10,000 times greater than normal. The increase of particles at this energy level still poses no appreciable hazard to air travelers, astronauts or satellites, and this radiation storm is rated by the NOAA as a moderate S2 to S3, on a scale that goes to S5.

Press contacts:

Dr. Paal Brekke
Tel: +1-301-996-9028
E-mail: pbrekkeesa.nascom.nasa.gov

Dr. Bernhard Fleck
Tel: +1-301-996-9026
E-mail: bfleckesa.nascom.nasa.gov