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The Search for Activity on Dione and Tethys With Cassini VIMS and UVIS
Author(s) -
Buratti B. J.,
Hansen C. J.,
Hendrix A. R.,
Esposito L. W.,
Mosher J. A.,
Brown R. H.,
Clark R. N.,
Baines K. H.,
Nicholson P. D.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl078165
Subject(s) - astrobiology , atmosphere (unit) , icy moon , saturn , magnetosphere , physics , plume , astronomy , ultraviolet , spectral signature , infrared , geology , planet , remote sensing , meteorology , optics , plasma , quantum mechanics
During the Cassini mission the Saturnian moons Dione and Tethys showed intriguing and multiple clues suggesting residual geologic activity that might be detectable as an atmosphere, plume, or even heat signature. These clues included an atmospheric aura around Dione, injection of particles into Saturn's magnetosphere, mysterious red streaks on Tethys, and possible cryovolcanic features on Dione. A concerted effort that was strengthened in the latter stages of the mission included the acquisition of stellar occulations by the Ultraviolet Imaging Spectrograph (UVIS) of both Dione and Tethys and high solar phase observations of Dione by the Visible Infrared Mapping Spectrometer (VIMS) to detect forward scattering from grains in a plume. Analysis of these observations shows no evidence for even a low level of activity on either moon. In addition, infrared images at 2.65 μm obtained throughout the mission were scrutinized for the reappearance of an atmosphere‐like aura, with negative results.