NASA has recently detected mysterious sounds originating from space thanks to their Van Allen probes orbiting Earth. Although space is technically a vacuum, it is not empty or silent, says the US space agency.
Space is not empty, nor is it silent. The region around Earth is filled with magnetic field lines and trapped energetic particles, zooming about in a high-speed dance around the planet (shown here in an illustration). Credit: NASA’s Goddard Space Flight Center/Brian Monroe.
Although space is technically a vacuum, it is not empty or silent, says the US space agency. Now, experts have recorded strange sounds above our planet and even know what’s causing them, and no, it’s not aliens.
According to experts, the chilling noise is produced by plasma waves in the magnetic field that surrounds Earth. These sounds have been recorded with the aid of the Van Allen probes, which allow scientists to “listen to the sounds of space and how different elements interact,” the agency reports on its website.
The Van Allen probes are currently studying Van Allen’s electrical and magnetic radiation belts, which surround our planet.
Different types of plasma waves triggered by various mechanisms, occupy different regions of space around Earth. Credit: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith.
The probes use an instrument called the Electric and Magnetic Field Instrument Suite and Integrated Science or EMFISIS for short that measures electric and magnetic waves as they circle our planet. When one of the probes encounters a wave, its sensors record the changes in the frequency of the electric and magnetic fields.
As noted by NASA on their website, “Space is not empty, nor is it silent. While technically a vacuum, space nonetheless contains energetic charged particles, governed by magnetic and electric fields, and it behaves, unlike anything we experience on Earth.”
The Space Agency adds: “In regions laced with magnetic fields, such as the space environment surrounding our planet, particles are continually tossed to and fro by the motion of various electromagnetic waves known as plasma waves. These plasma waves, like the roaring ocean surf, create a rhythmic cacophony that—with the right tools—we can hear across space.”
Experts explain that just as waves roll across the ocean or storm fronts move through the atmosphere, disturbances in space can cause waves. These waves occur when the electric and magnetic fields fluctuate through groups of ions and electrons that make up the plasma, pushing some at accelerated speeds. This interaction controls the balance of highly energetic particles injected and lost from in the near-Earth environment.
“By understanding how waves and particles interact, scientists can learn how electrons are accelerated and lost from the radiation belts and help protect our satellites and telecommunications in space,” writes Mara Johnson-Groh on NASA’s website.