Radiation Belt Around Earth Appears and Disappears In One Month, Scientists Discover in Study
ByFor just under 60 years, scientists believed two radiation rings surrounded the Earth, but a recent discovery suggests otherwise, according to a news release.
Space scientists at UCLA reported from a February discovery a third radiation ring that only appeared for about a month in Sept. 2012. The new ring was spotted in between the Van Allen radiation belts, discovered in 1958.
The Van Allen radiation belts are two doughnut-shaped circles that encompass the Earth and are each made up of high-energy electrons. The electrons are believed to be so close together they travel close to the speed of light.
The study, published Sunday in the journal Nature Physics, from UCLA reported and explained the highly unusual behavior of the third radiation belt.
"In the past, scientists thought that all the electrons in the radiation belts around the Earth obeyed the same physics," said Yuri Shprits, a research geophysicist with the UCLA Department of Earth and Space Sciences. "We are finding now that radiation belts consist of different populations that are driven by very different physical processes."
Shprits said the Van Allen is a hazard to other spacecraft and satellites. It can cause random anomalies and also complete failure in the other space exploring crafts. He said understanding spatial radiation is vital to better protecting people and equipment.
The third ring was found to be made up of ultra-relativistic electrons, which are also present in both the outer and inner rings. Adam Kellerman, research associate in Shprits' team, said these ultra-relativistic electrons can penetrate the most sophisticated shielding of satellites in space.
"Their velocity is very close to the speed of light, and the energy of their motion is several times larger than the energy contained in their mass when they are at rest," Kellerman said. "The distinction between the behavior of the ultra-relativistic electrons and those at lower energies was key to this study."
Shprits said more will need to be done to solve the problem, but the team took an important first step.
"I believe that, with this study, we have uncovered the tip of the iceberg," Shprits said. "We still need to fully understand how these electrons are accelerated, where they originate and how the dynamics of the belts is different for different storms."