From the depths of the oceans to the peaks of Mt. Everest, humanity's impact on the environment cannot be overstated. Now, NASA reports that we are actually impacting space as well, but this time, it is helping the planet.
NASA reports that its Van Allen probe has discovered that very low frequency (VLF) broadcasts have created a protective bubble around Earth, shielding the planet from harmful radiation.
"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 in Westford, Massachusetts.
The VLF Bubble
The average person doesn't interact with VLF radio communications on a regular basis. In fact, most people will go their whole lives without using them as these require very large antennas and are thus usually confined to military or scientific endeavors. The most common use of VLF is as a means of communications for submarines.
"VLF signals are transmitted from ground stations at huge powers to communicate with submarines deep in the ocean," says NASA in a press release. "While these waves are intended for communications below the surface, they also extend out beyond our atmosphere, shrouding Earth in a VLF bubble."
NASA adds that this VLF bubble can even be seen by spacecraft traveling high above the surface of the planet, such as the Van Allen Probes, which analyze near-Earth ions and electrons.
Scientists speculate that this VLF barrier is actually keeping the Van Allen belts, a layer of radiation trapped within Earth's magnetic field, away from the planet. Without this VLF bubble, it is believed that the Van Allen radiation belt would be much closer to the planet than it currently is.
Humanity's Effect On The Weather In Space
Aside from the VLF barrier surrounding Earth, Erickson and his team also studied how Cold War-era weapons tests have affected the Earth's atmosphere. Those tests have long since concluded, but Erikson is hopeful that the study of their effects will shed light on natural occurrences in space.
"The tests were a human-generated and extreme example of some of the space weather effects frequently caused by the sun," said Erickson. "If we understand what happened in the somewhat controlled and extreme event that was caused by one of these human-made events, we can more easily understand the natural variation in the near-space environment."
The researchers' study into human-induced weather in space is featured in Space Science Reviews.
