More Solar Flares Blast Toward Earth

Dec. 15, 2006 — -- A large electromagnetic "storm" has broken out on the face of the sun, sending masses of charged subatomic particles through the space that surrounds planet Earth.

Images from the SOHO space probe -- short for Solar and Heliospheric Observatory -- showed a bright flare near the sun's equator on Wednesday, and another was reported by ground-based observatories today.

Several of SOHO's sensors were temporarily overwhelmed by the amount of radiation, engineers said.

Such flares, known as coronal mass ejections, are actually fairly common, scientists say. Earth is well protected by both its atmosphere and its magnetic field.

The 10 least protected human beings are those currently in orbit -- the crews of the Space Shuttle Discovery and the International Space Station.

The flare had one surprising effect: It temporarily knocked out the gyroscopes that keep the space station oriented in orbit.

Apparently, NASA said, the energy from the flare caused the outer layers of Earth's atmosphere to thicken slightly.

Even at the station's altitude of 220 miles, there's a tiny bit of air -- and there was more on Thursday.

The gyroscopes had been turned off this week, while astronauts Robert Curbeam and Christer Fuglesang did two spacewalks to update the station's wiring.

When the gyros were turned back on, onboard computers sensed that they were working harder than they ought to -- and shut the gyros off again.

NASA said the astronauts were in no danger. The shuttle's steering jets will keep the docked ships stable until the gyro problem is solved.

Overnight the astronauts were instructed to sleep in sections of their ships that were the best shielded from radiation. NASA said the shuttle mission schedule would not be changed because of the solar storm.

Earth on the Lookout

Here on Earth, the most visible effect of the flare was the aurora borealis -- the so-called Northern Lights, often seen over Alaska and Canada at night.

Late Thursday and early today, aurora displays were reported as far south as Michigan and Minnesota.