Praise be to the radio-induced space bubble.
Concept art of VLF bubble. Image: NASA's Goddard Space Flight Center/Genna Duberstein
Humans have accidentally created a protective bubble around Earth by using very low frequency (VLF) radio transmissions to contact submarines in the ocean. It sounds nuts, but according to recent research published in Space Science Reviews, underwater communication through VLF channels has an outer space dimension.
This video explainer, released by NASA on Wednesday, visualizes how radio waves wafting into space interact with the particles surrounding Earth, and influence their motion.
Satellites in certain high-altitude orbits, such as NASA's particle-watching Van Allen Probes, have observed these VLF ripples creating an "impenetrable boundary," a phrase coined by study co-author Dan Baker, director of the University of Colorado's Laboratory for Atmospheric and Space Physics. This doesn't mean impenetrable to spacecraft or asteroids, per se, but rather to potentially harmful particle showers created by turbulent space weather.
The boundary extends out to the inner edge of the Van Allen radiation belts, which are bands of charged particles created from the clash of the solar wind against Earth's magnetic field. The VLF bubble might actually be pushing the Van Allen belts farther into space, suggests Baker, considering that they have receded farther from Earth since the 1960s, when VLF use was not as widespread.
This byproduct of submarine dispatches is one of a few ways in which humans are known to have influenced space weather (nuclear weapons testing is another). Next, scientists are figuring out whether the VLF bubble can be used to purify the near-Earth environment from charged particles, which would make humanity a little safer. Well done, random radio-induced space cocoon.
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