NASA Announces Incoming CME Likely to Cause a Geomagnetic StormChris Carrington The NOAA Space Weather Prediction Center (SWPC) has the following information for the 9th, 10th and 11th January: The risk from flares today stands at 80% for an M-class and 50% for an X-class. Any eruption is most likely to come from somewhere within AR1944, though it has grown so massive its hard to see where AR1943 ends and AR1944 begins. A good explanation of how all these things fit together is provided by NASA: Coronal mass ejections are more likely to have a significant effect on our activities than flares because they carry more material into a larger volume of interplanetary space, increasing the likelihood that they will interact with the Earth. While a flare alone produces high-energy particles near the Sun, some of which escape into interplanetary space, a CME drives a shock wave which can continuously produce energetic particles as it propagates through interplanetary space. When a CME reaches the Earth, its impact disturbs the Earths magnetosphere, setting off a geomagnetic storm. A CME typically takes 3 to 5 days to reach the Earth after it leaves the Sun. Observing the ejection of CMEs from the Sun provides an early warning of geomagnetic storms. Only recently, with SOHO, has it been possible to continuously observe the emission of CMEs from the Sun and determine if they are aimed at the Earth. One serious problem that can occur during a geomagnetic storm is damage to Earth-orbiting satellites, especially those in high,geosynchronous orbits. Communications satellites are generally in these high orbits. Either the satellite becomes highly charged during the storm, and a component is damaged by the high current that discharges into the satellite, or a component is damaged by high-energy particles that penetrate the satellite. We are not able to predict when and where a satellite in a high orbit may be damaged during a geomagnetic storm. Another major problem that has occurred during geomagnetic storms has been the temporary loss of electrical power over a large region. The best known case of this occurred in 1989 in Quebec. High currents in the magnetosphere induce high currents in power lines, blowing out electric transformers and power stations. This is most likely to happen at high latitudes, where the induced currents are greatest, and in regions having long power lines and where the ground is poorly conducting. The damage to satellites and power grids can be very expensive and disruptive. Fortunately, this kind of damage is not frequent. Geomagnetic storms are more disruptive now than in the past because of our greater dependence on technical systems that can be affected by electric currents and energetic particles high in the Earths magnetosphere. Chris Carrington is a writer, researcher and lecturer with a background in science, technology and environmental studies. Chris is an editor for The Daily Sheeple, where this first appeared.Wake the flock up! 