Washington:
A man-made ‘bubble’ or barrier around our planet Earth has been spotted by US space agency NASA, said scientists. According to them, the human-made bubble blocks high-energy space radiation from reaching Earth.
The landscape of the Earth has long been shaped by human beings but now it has been discovered that we humans can also shape our near-space environment.
It has been found that the very low frequency (VLF) radio communications interact with the particles in space and affect where and how they move. At times, these interactions create a barrier around the Earth and act as a shield against natural high energy particle radiation in space.
“A number of experiments and observations have figured out that, under the right conditions, radio communications signals in the VLF frequency range can in fact affect the properties of the high-energy radiation environment around the Earth,” said Phil Erickson, assistant director at the Massachusetts Institute of Technology (MIT) Haystack Observatory in the US.
The VLF signals communicate with submarines deep in the ocean as they are transmitted from ground stations at huge powers.
These waves not only perform communications below the surface but also extend out beyond our atmosphere, shrouding Earth in a VLF bubble.
Spacecraft such as NASA’s Van Allen Probes, could even see this bubble high above the surface of the Earth. The Van Allen Probes has been designated to study electrons and ions in the near-Earth environment.
The probes spotted an interesting coincidence that the VLF bubble’s outward extent corresponds almost exactly to the inner edge of the Van Allen radiation belts, a layer of charged particles held in place by Earth’s magnetic fields.
Dan Baker from the University of Colorado in the US coined this lower limit the “impenetrable barrier” and speculates that if there were no human VLF transmissions, the boundary would likely stretch closer to Earth.
Indeed, comparisons of the modern extent of the radiation belts from Van Allen Probe data show the inner boundary to be much farther away than its recorded position in satellite data from the 1960s, when VLF transmissions were more limited.
With further study, VLF transmissions may serve as a way to remove excess radiation from the near-Earth environment.
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Plans are already underway to test VLF transmissions in the upper atmosphere to see if they could remove excess charged particles - which can appear during periods of intense space weather, such as when the sun erupts with giant clouds of particles and energy.
The research was published in the journal Space Science Reviews.
(With inputs from PTI)
