Photometrically-corrected Global Infrared Mosaics Of Enceladus: New Implications For Its Spectral Diversity And Geological Activity

©astro-ph.EP

Global mosaics of incidence, emergence, phase angles and the pixel spatial resolution

Between 2004 and 2017, spectral observations have been gathered by the Visual and Infrared Mapping Spectrometer (VIMS) on-board Cassini (Brown et al., 2004) during 23 Enceladus close encounters, in addition to more distant surveys.

The objective of the present study is to produce a global hyperspectral mosaic of the complete VIMS data set of Enceladus in order to highlight spectral variations among the different geological units. This requires the selection of the best observations in terms of spatial resolution and illumination conditions. We have carried out a detailed investigation of the photometric behavior at several key wavelengths (1.35, 1.5, 1.65, 1.8, 2.0, 2.25, 2.55 and 3.6 μm), characteristics of the infrared spectra of water ice.

We propose a new photometric function, based on the model of Shkuratov et al. (2011). When combined, corrected mosaics at different wavelengths reveal heterogeneous areas, in particular in the terrains surrounding the Tiger Stripes on the South Pole and in the northern hemisphere around 30°N, 90°W. Those areas appear mainly correlated to tectonized units, indicating an endogenous origin, potentially driven by seafloor hotspots.

Rozenn Robinel, Stéphane Le Mouélic, Gabriel Tobie, Marion Massé, Benoît Seignovert, Christophe Sotin, Sébastien Rodriguez
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Journal reference: Icarus (2020)
DOI: 10.1016/j.icarus.2020.113848
Cite as: arXiv:2006.00146 [astro-ph.EP] (or arXiv:2006.00146v1 [astro-ph.EP] for this version)
Submission history
From: Benoît Seignovert
[v1] Sat, 30 May 2020 01:59:05 UTC (8,573 KB)
https://arxiv.org/abs/2006.00146
Astrobiology, Astrochemistry

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