Tuesday, 21 July 2015
in 1960, NASA detected mysterious plasma waves in the Van Allen radiation belts, the donut-shaped rings surrounding the Earth that contain high-energy particles trapped by the planet's magnetic field.
Half a century later, Yuri Shprits, a research geophysicist in the UCLA College, and his colleagues discovered the structure of these waves when they are very close to the equator. The scientists observed 13 equally spaced lines measured by two European Space Agency Cluster satellites, and found highly structured wave spectrograms that look like a zebra pedestrian crossing.
The European Cluster spacecraft observed ring distributions of protons in space that provide the energy for the plasma waves. Modelling of waves based on these observations provided additional evidence that waves are excited by so-called proton ring distributions resulting in wave generation of such high energy particles into the atmosphere
