NASA/AP
NASA probes found a human-made "barrier" is surrounding Earth and protecting the planet from space weather, according to a report published in Science Space Review. The barrier can form when very low frequency (VLF) radio waves — largely used for submarine communications and scientific studies — interact with particles in space.
Why it matters: Earth is bombarded with intense radiation and energy ejected from the sun that can sometimes disrupt satellite communications and power grids. Scientists plan to investigate whether ultimately they could purposely use VLF signals to push this excess radiation farther away from Earth.
The discovery: Researchers found that the barrier, which forms under certain conditions, has actually been pushing Earth's Van Allen radiation belts away for decades. Using satellite data, they compared the inner edge of those belts today vs. in the 1960s when there were fewer VLF communications, and discovered the inner edge is farther away today.
Two quick things:
- VLF communications are weaker frequencies usually used to transfer coded messages across long distances or under deep water, but their use has evolved over the last 50 years.
- Earth's two Van Allen belts are collections of charged particles, largely from solar winds, trapped in rings by the planet's magnetic field. The inner belt sits 400 to 6,000 miles above Earth's surface and the outer is 8,400 to 36,000 miles above.