There is an area in the South Atlantic where satellites experience electrical problems and astronauts see flashes in their eyes during periods of high solar activity. The effect is called the "South Atlantic Anomaly." At present, the danger zone for satellites covers Brazil and the South Atlantic, but it is growing wider towards the southern Indian Ocean. Scientists have found the Earth's magnetic field is growing weaker at an astonishing rate and some believe the magnet field may disappear completely in a thousand years or so, perhaps due to a swap between the north and south magnet poles, as has happened before in Earth's long history.
The South Atlantic Anomaly is one of the reasons scientists are taking a closer look at Earth's magnetism. The European Space Agency (ESA) has summarized the planned research in the article Focus on our magnetic planet. The article describes the ESA "Swarm" project, which will use three satellites to measure the Earth's magnetic field and its variations more accurately than any previous measurements. The Swarm satellites are planned to be operational by 2009 and last until 2013, which should catch the next peak in solar activity.
Nils Olsen at the Danish National Space Center in Copenhagen explained his interest in the Swarm project, "What excites us is the huge scope of what we can study even with quite small satellites. By making magnetic measurements in space we get new information about the Earth, from the molten core deep under our feet, through the mantle, to the crust on which we live. And then we go on upwards into the upper atmosphere, through the planet's local space environment, and all the way to the Sun itself, which is the source of daily magnetic disturbances."
The Swarm project will have practical benefits. Solar storms can destroy satellites. While the impact of radiation on satellite systems is well understood, a new danger has been discovered. "The atmosphere inflates and low-orbiting spacecraft run into unexpected air resistance. Experts used to think it was just a matter of the air being heated by particles and electric currents in the regions around the poles, where auroras occur. Now a sensitive French-built accelerometer on the German CHAMP satellite has revealed heating by intense currents where the solar wind pushes towards the magnetic poles in daytime," noted the ESA article. The Swarm satellites include accelerometers and will investigate this effect.
ESA's Focus on our magnetic planet describes other research. Please read it for additional information on this topic .For current solar/geomagnetic conditions, visit www.spaceweather.com.
