Researchers from Massachusetts Institute of Technology [MIT] and University of Colorado have discovered an invisible shield some 11,000 km above Earth that works against the harmful radiation belt of electrons.
Exposure to such high-energy radiation can wreak havoc on satellite electronics and pose serious health risks to astronauts.Using NASA's Van Allen Probes, that are orbiting within the harsh environments of the Van Allen radiation belts, researchers found no matter where these electrons are circling around the planet's equator, they can get no further than about 11,000 km from the Earth's surface.
“What is keeping this high-energy radiation at bay seems to be neither the Earth's magnetic field nor long-range radio waves but rather a phenomenon termed 'plasmaspheric hiss',” explained John Foster, associate director of MIT's Haystack Observatory.The phenomenon is described as very low-frequency electromagnetic waves in the Earth's upper atmosphere.
The researchers believe that plasmaspheric hiss essentially deflects incoming electrons causing them to collide with neutral gas atoms in the Earth's upper atmosphere and ultimately disappear.
“It is a very unusual, extraordinary and pronounced phenomenon. What this tells us is if you parked a satellite or an orbiting space station with humans just inside this impenetrable barrier, you would expect them to have much longer lifetimes. That is a good thing to know,” Foster added.
[The Van Allen belts are a collection of charged particles - gathered in place by Earth’s magnetic field.The Van Allen belts was discovered in 1958.]