Humans Create Artificial Barrier around Earth
NASA space probes have discovered an artificial barrier around Earth created through human activity—showing we are not only responsible for shaping the environment on land, but that we are now having an impact on space too.
The barrier, which comes and goes, is the result of very low frequency radio communications interacting with particles in space, which results in a sort of shield protecting Earth from high energy radiation in space.
This, scientists say, is potentially very good news, as we could use the barrier to protect Earth from extreme space weather resulting from events like coronal mass ejections—huge explosions on the sun, where plasmas and magnetic field are ejected from its corona, the outermost part of its atmosphere. These ejections can result in geomagnetic storms, which have the potential to knock out communication satellites and power grids.
NASA scientists detected the barrier with the Van Allen Probes, which are designed to study electrons and ions in our new-space environment. Normally, very low frequency (VLF) signals from radio telescopes are transmitted from the ground and are used to communicate with submarines, deep below the surface of the ocean. However, they also end up going into the atmosphere.
The result is a massive “VLF bubble” enshrouding Earth, NASA said. The bubble can be seen high above Earth’s surface in the space environment surrounding it.
Further analysis showed the bubble extends almost exactly to the inner edge of Van Allen radiation belts. These three belts are zones of energetic charged particles that come from solar wind—the particles are then captured and held by Earth’s magnetic field. When the VLF bubble interacts with the radiation belts, it creates the barrier observed.
“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,” Phil Erickson, one of the scientists involved, said in a statement.
Researchers say that if there were no VLF bubble, the radiation belt boundary would be far closer to Earth than it is. Data from the 1960s indicates the inner limit of the Van Allen radiation belt used to be far closer to Earth, when the use of VLF was more limited.
As the VLF barrier appears to protect Earth, scientists say it could be used to remove excess radiation from the space surrounding Earth and NASA is now planning to carry out tests to see if this could work.