This colourful spectrogram represents data collected by Cassini’s Radio and Plasma Wave Science instrument as it crossed through Saturn’s D-ring on 28 May 2017.
As tiny, dust-sized particles strike Cassini and its antennas, the particles are vaporised into tiny clouds of plasma, or electrically excited gas. These tiny explosions make a small electrical signal that Cassini can detect. The data can be converted to visible and audio formats.
Particle impacts are seen to increase in frequency in the spectrogram and in the audible ‘pops’ around the time of ring crossing as indicated by the red/orange spike just before 14:23 on the plot shown here.
Labels on the x-axis indicate time (top line), distance from the planet’s centre in Saturn radii, or Rs (middle), and latitude on Saturn beneath the spacecraft (bottom).
More about this image, including audio
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