NASA scientists detect barrier around Earth

NASA scientists detect barrier around Earth

NASA’s Van Allen probes have revealed human activities are not having physical and chemical impacts on Earth’s environment, but also on radio frequencies extending out into space.

After analyzing data captured by the probes, NASA scientists concluded that very low frequency (VLF) radio communications make interactions with particles in space, forming an artificial barrier that can block high-energy particle rays from space.

VLF communications are mainly used to communicate with submarines across massive distances in the ocean from very powerful ground stations.

In spite of VLF communications being directed in a descending direction, these communications can also extend above the surface, which creates a VLF bubble that can be detected by spacecraft.

MIT Haystack Observatory’s assistant director Phil Erickson said, “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.”

Scientists are now studying VLF radio transmissions’ ability to impact the near-Earth environment in further detail. They are probing the odds of using VLF transmissions in the upper atmosphere to allay the effects of charged particles on spacecraft that are susceptible to adverse space events like coronal mass ejections (CMEs) from the Sun.

An official NASA release informed..

Humans have long been shaping Earth’s landscape, but now scientists know we can shape our near-space environment as well. A certain type of communications — very low frequency, or VLF, radio communications — have been found to interact with particles in space, affecting how and where they move. At times, these interactions can create a barrier around Earth against natural high energy particle radiation in space. These results, part of a comprehensive paper on human-induced space weather, were recently published in Space Science Reviews.

“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 MIT Haystack Observatory, Westford, Massachusetts.

VLF signals are transmitted from ground stations at huge powers to communicate with submarines deep in the ocean. While these waves are intended for communications below the surface, they also extend out beyond our atmosphere, shrouding Earth in a VLF bubble. This bubble is even seen by spacecraft high above Earth’s surface, such as NASA’s Van Allen Probes, which study electrons and ions in the near-Earth environment.

The probes have noticed an interesting coincidence — the outward extent of the VLF bubble 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, director of the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder, 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.

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