Abstract The Pioneer 11 Infrared Radiometer instrument made observations of Saturn and its rings in broadband channels centered at 20 and 45 μm and obtained whole-disk information on Titan. A planetary average effective temperature of 96.5±2.5 K implies a total emission 2.8 times the absorbed sunlight. Correlation with radio science results implies that the molar fraction of H2 is 90±3% (assuming the rest is He). Temperatures at the 1 bar level are 137 to 140 K; regions appearing cooler may be overlain by a cloud acting as a 124 K blackbody surface. A minimum temperature averaging 87 K is reached near 0.06 bars. Ring boundaries and optical depths are consistent with those at optical wavelengths. Ring temperatures are 64–86 K on the south (illuminated) side, ∼54 K on the north (unilluminated) side, and at least 67 K in Saturn's shadow. There is evidence for a south to north drop in ring temperatures. Titan's 45 μm brightness temperature is 75±5 K.


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    Title :

    Scientific results from the pioneer Saturn infrared radiometer


    Contributors:
    Orton, G.S. (author) / Ingersoll, A.P. (author) / Froidevaux, L. (author) / Neugebauer, G. (author) / Münch, G. (author) / Chase, S.C. (author)

    Published in:

    Publication date :

    1981-01-01


    Size :

    4 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English