Solar Flare Hurls Radiation Surge

A major solar flare on the sun Thursday hurled a surge of radiation toward the Earth that may disrupt communications and electrical power transmission over the next two days, government scientists said.

Norman Cohen, a geophysical forecaster at the Space Environment Services Center run by the National Oceanic and Atmospheric Administration in Boulder, Colo., said he was sending alerts to electrical utilities in Canada and in the northern United States to expect possible power surges.

Powerful solar flares can also affect satellites and spacecraft, but officials at the National Aeronautics and Space Administration said they have evaluated the burst of energy and determined that astronauts on board the orbiting space shuttle Atlantis are not in any danger.

“In the orbit we’re in, at 160 mile altitude, it is no threat at all,” said Ronald D. Dittemore, a flight director at the Johnson Space Center in Houston.

A NASA spokesman said engineers were checking for any effect on Galileo, the probe released from Atlantis six hours after the space shuttle was launched Wednesday. Galileo on Thursday afternoon was more than 200,000 miles from Earth on its six-year journey to Jupiter.

Cohen said the GOES satellite first detected the solar flare at 5:30 a.m. PDT and that the X-rays from the flare surged higher than instruments on the satellite could measure. The flare was estimated at an X-13, a unit that measures X-ray flux. The GOES measures only up to X-12.