"Raise Shields!". This may be a battle cry in the Star Trek blockbuster, but according to space scientists, planet Earth has its own built-in invisible shield for deadly electrons, which creates a protective zone at orbital altitudes.
High energy particles, including electrons and protons, are known to rotate around our planet at relativistic speeds. For example, high-energy electrons travel at a speed of about 100,000 kilometers per second. These particles, which are located in two zones above the Earth’s atmosphere, cause satellite damage, and also pose a danger to astronauts who are about to leave Earth’s orbit.
Van Allen - the man who unveiled the famous Van Allen Belts
Discovered in 1958 by James Van Allen and his team from the University of Iowa, these famous Van Allen Belts, which consist of an inner belt and an outer belt, stretched 25,000 km above the earth's atmosphere. In 2013, Daniel Baker of the University of Colorado, Boulder, used data obtained by NASA's Van Alenna probes to detect the third belt between the classic inner and outer belts. Van Allen satellites continue to rotate around the Earth, giving us an unprecedented view of this dynamic and fascinating area. Now, according to a new study published in Nature, November 27, Baker and his colleagues have discovered anomalies at the inner edge of these belts. They noted an invisible barrier that blocks high energy electrons from contact with our atmosphere.
“It’s like putting these electrons in a glass jar in space,” Baker said in a press release. "Something like a shield created by the force fields in the Star Trek movie that was used to repel alien weapons, we see high above the Earth’s atmosphere, which blocks these electrons. This is a very mysterious phenomenon."
Just as Van Allen Belts are sandwiched between the magnetic layers of the Earth’s magnetosphere, the Baker team suggests that there must be a magnetic barrier that acts as a shield. But, oddly enough, it seems that it is not. Perhaps there is a layer of scattering of electrons that forms the boundaries? But this hypothesis is not consistent with the observations.
"Nature does not tolerate strong gradients and generally finds ways to smooth them, so we expect some of the relativistic electrons to move inwards, and some to the outside," said Baker. "This is not obvious, because the slow, gradual processes that need to be involved in the movements of these particles cannot create such a clear boundary in space." Now researchers are focused on a cold cloud of electrically charged gas, which, as you know, surrounds the Earth, starting from a height of 600 miles. This cloud, known as the plasmasphere, spreads thousands of miles into the Van Allen Belt and can be disastrously interacting with high energy particles, thereby blocking them from entering our atmosphere. High-energy electrons will be stopped on their journey at a clear 7,200-mile border. In short, this plasmasphere can is a Star Trek shield for our planet.