The NASA Van Allen twin probes launched last year have revealed that the Earth is a giant particle accelerator. Recently it was reported that particles in the magnetosphere sometimes accelerate across distances of a few hundred meters. But the newer discovery shows the acceleration can occur across hundreds of thousands of kilometers. The data will be helpful to to scientists helping satellite operators and the International Space Station to predict and prepare for the destructive tendencies of the seemingly random fluctuations that can occur in the magnetosphere.
The Earth has two radiation belts (and for a few weeks earlier this year, three) surrounding it called the Van Allen belts. The belts help protect life on our planet from solar eruptions, but those same eruptions can cause the belts to expand and contract unpredictably. These activities have been linked to satellite outages.
The new data was collected by an instrument on-board the satellites and analyzed by scientists at the University of New Hampshire, the organization in charge of that particular instrument. The near-light-speed ("relativistic") acceleration of the high-energy particles in the belts is caused by "ultra-low frequency electromagnetic waves operating on a planetary scale," ScienceDaily explains. The particles move from west to east.
"Now we're seeing this large-scale, global motion involving ultra low-frequency waves pulsing through Earth's magnetosphere and operating across vast distances up to hundreds of thousands of kilometers," said one scientist connected with the research.
The magnetosphere has been a hot topic for spacefarers in recent years. Last month, the European Space Agency launched a different pair of probes called "Swarm" to study the magnetosphere at all levels. Like the Van Allen probes, they work in tandem to produce wider, more accurate results.