Van Allen Probes EMFISIS Waves
Spooky Chorus 2016-10-27

For Halloween we present some spooky chorus recorded by the Van Allen Probes A spacecraft in Earth orbit. These waves may contribute to the acceleration of electrons in Earth's radiation belts up to speeds that allow them to penetrate and damage spacecraft -- the notorious "killer electrons"! This particular example has some ghostly sounding features.

These signals were recorded by the EMFISIS Waves instrument on 2016-10-27 during hour 15 UTC. The measurements of three orthogonal magnetic antennas Bu, Bv, and Bw were combined to make the 2-minute stereo audio recording.

The video presents a frequency-time spectrogram for the three antennas, with a moving cursor that shows the time position of the audio track. Time advances from left to right along the horizontal axis, frequency ranges from low to high frequencies along the vertical axes, and the amplitude of the signals is color coded with blue indicating weak signals and red indicating strong signals.