Previously unknown known space barrier now a known known
- Hey wait a minute
But once they realised that VLF signals can actually influence the movement of the charged particles within these radiation belts, they realised that our unintentional human-made barrier has been progressively pushing them back.
One of the team, Dan Baker, from the University of Colorado's Laboratory for Atmospheric and Space Physics, referred to this as the "impenetrable barrier".
While our protective VLF bubble is probably the best influence we humans have made on the space surrounding our planet, it's certainly not the only one - we've been making our mark on space since the 19th century, and particularly over the past 50 years, when nuclear explosions were all the rage.
https://www.sciencealert.com/there-is-a-human-made-barrier-surrounding-earth-and-we-can-detect-it