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<A href="http://www.telegraph.co.uk/science/space/9902765/Third-radiation-belt-discovered-around-Earth.html"><FONT size=3>http://www.telegraph.co.uk/science/space/9902765/Third-radiation-belt-discovered-around-Earth.html</FONT></A><BR>
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<FONT size=3>Third radiation belt discovered around Earth</FONT><BR>
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<FONT size=3>A previously unknown belt of radiation surrounded Earth for several weeks last year,<BR>Nasa scientists have discovered.</FONT><BR>
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<FONT size=3>A third belt can sometimes appear, the radiation is shown here in yellow, with green representing the spaces<BR>between the belts Photo: NASA/Rex Features</FONT><BR>
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<FONT size=3>By Nick Collins, Science Correspondent<BR>4:20PM GMT 01 Mar 2013</FONT><BR>
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<FONT size=3>Since 1958 scientists have known that Earth is circled by two doughnut-like rings of trapped<BR>charged particles called the Van Allen radiation belts.<BR>But now a third, temporary belt has been discovered after, appearing for a month last year before<BR>being dispersed by a shock wave released by the Sun.<BR>Astronomers hope to discover how often the third belt forms and learn more about the behaviour<BR>of all three belts, which can damage communications and GPS satellites and expose astronauts<BR>to extra doses of radiation.</FONT><BR>
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<FONT size=3>The Van Allen belts, named after their discovered James Van Allen, are known to periodically<BR>swell as a result of space weather and solar storms but the exact cause is poorly understood.<BR>The new observations, published in the Science journal, were made by Nasa's twin Van Allen<BR>probes which were launched on August 30 bearing hi-tech particle detection equipment.<BR>John Grunsfeld, NASA’s associate administrator for science, said: "The fantastic new<BR>capabilities and advances in technology in the Van Allen Probes have allowed scientists to see<BR>in unprecedented detail how the radiation belts are populated with charged particles and will<BR>provide insight on what causes them to change, and how these processes affect the upper reaches<BR>of Earth’s atmosphere."</FONT><BR>
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<FONT size=3>The outer of the two Van Allen belts had previously been seen as one blurry ring, but high<BR>resolution images taken by the Relativistic Electron Proton Telescope instrument on board the<BR>probes revealed two separate rings with a clear space in between. The new belt was visible for<BR>four weeks before being destroyed by a shock wave released by the Sun.<BR></FONT><BR>
<FONT size=3>Nicky Fox, Van Allen Probes deputy project scientist at the Johns Hopkins University, said:<BR>“We thought we knew the radiation belts, but we don’t. The advances in technology and<BR>detection made by NASA in this mission already have had an almost immediate impact on basic<BR>science."</FONT><BR>
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