BJones retuiteado

On this day in 1991, my photopolarimeter subsystem (PPS) was turned off due to degraded performance, saving 2.4 W of power.
The PPS was used to measure surface texture and composition, particle size distribution and composition in ring systems, and to study scattering and density of atmospheres.
The PPS was a 15 cm telescope with three polarizing filters as well as eight color filters, followed by a photomultiplier tube to amplify the dim conditions. Voyager 1's photomultiplier tube failed in November 1979 after the Jupiter encounter, and so the V1 PPS was never used again. All other Voyager PPS data therefore comes from Voyager 2.
Forty filter combinations were used in 24 second sequences using 400 ms exposures and 200 ms filter change timings. These filter sequences allowed amounts and states of Na, H, He, Ca, CO, O, Mg, Si, K, and CH3 to be derived, as well as scale heights in atmospheres.

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