WASHINGTON (Reuters) - A strong geomagnetic storm is racing from the Sun toward Earth, and its expected arrival on Thursday could affect power grids, airplane routes and space-based satellite navigation systems, US space weather experts said.
The storm, a big cloud of charged particles flung from the Sun at about 4.5 million miles per hour (7.2 million km per hour), was spawned by a pair of solar flares, scientists said. This is probably the strongest such event in nearly six years, and is likely more intense than a similar storm in late January, said Joseph Kunches, a space weather specialist at the U.S. National Oceanic and Atmospheric Administration (NOAA). This solar disturbance is a three-stage affair, or as Kunches said in a telephone interview from Boulder, Colorado: “We hit the trifecta.” These are the stages he described, with the first two already affecting Earth:
* First, two solar flares moving at nearly the speed of light reached Earth late on Tuesday. Such flares can cause radio blackouts. * Then, solar radiation hit Earth’s magnetic field on Wednesday, with possible impact on air traffic, especially near the poles, satellites and any astronauts taking space walks. This phase could last for days. * Finally, the plasma cloud sent by the coronal mass ejection, which is basically a big chunk of the Sun’s atmosphere, is expected to arrive at Earth early on Thursday.