SCIENCE -- February 17, 2011 at 6:25 PM ET
Powerful Solar Flares Headed Toward Earth
The most powerful solar flares in four years blasted toward Earth Thursday, raising fears about disruption to communication and navigation satellites.
Solar flares, or coronal mass ejections, are caused when bursts of charged particles are released as magnetic energy from the sun, forcing a ring of light to radiate from the sun's atmosphere.
When the radiation strikes the earth's magnetic shield, it can cause interruptions to communications and power grids. Rare sightings of the northern lights may also be visible to those living in the northern United States.
The flare's effects are not expected to be severe. Dean Pesnell, a scientist at the Solar Dynamics Observatory at NASA, said that although disruptions might be noticeable, the particles won't strike at full force.
Technological disruptions have already been reported by Chinese state media, but the bulk of interfering geomagnetic activity is expected late Thursday and Friday. Pesnell explained that China's radio system was hit as the flares approached, because it was facing the sun.
"We would have had those same radio effects had we been turned toward the sun but it happened to be night where we are, so we didn't see them," Pesnell said. "Those are normal, they're expected and they weren't severe or unusually large."
Scientists will receive a 30-minute warning from a NASA satellite before the charged particles descend on Earth's magnetic shield.
The above video from NASA, spanning 11 hours, shows the flares departing from the sun on Tuesday.
Photo courtesy NASA