Van Allen Probes Surf through Waves in Space

The two populations of hiss, low and high frequency, inhabit two separate regions in near-Earth space.
Credits: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith

The space surrounding our planet is full of restless charged particles and roiling electric and magnetic fields, which create waves around Earth. One type of wave, plasmaspheric hiss, is particularly important for removing charged particles from the Van Allen radiation belts, a seething coil of particles encircling Earth, which can interfere with satellites and telecommunications. A new study published in Journal of Geophysical Research using data from NASA’s Van Allen Probes spacecraft has discovered that hiss is more complex than previously understood.

The new study looked at a newly identified population of hiss waves at a lower frequency than usually studied. These low-frequency hiss waves are particularly good at cleaning out high-energy particles — those that can cause damage to satellites — from the radiation belts. The authors of the study noticed that low-frequency waves are actually a separate and unique population, tending to cluster in different regions around Earth compared to their high-frequency counterparts.

The complete article is found here.