NASA's twin Van Allen probes mission has identified a hitherto unknown third ring of radiation around Earth , suggesting that there are unexpected structures and processes in these regions of space.
Previous observations of the Van Allen belts that surround the Earth revealed, half a century ago, two clear regions of trapped radiation around our planet. Particle detection instruments aboard the twin Van Allen probes, launched on August 30, now reveal the existence of a new, transient radiation belt. And they highlight the variable and dynamic nature of the rings that surround the planet. According to the journal Science , the new ring formed in early September 2012 and persisted for more than four weeks , until it was destroyed by a powerful shock wave from the Sun.
"Even 55 years after their discovery, the radiation belts of the Earth manage to surprise us and show that they hide mysteries to be discovered," says Nicky Fox, a physicist at Johns Hopkins University (USA) who participates in the project. Scientists hope that the data collected by the probes will help explain the effects of space weather on our planet , as well as understand the physical processes observed around other bodies in our own solar system and distant nebulae.
