Premium
Visible and thermal infrared observations of the Martian surface during three Phobos shadow transits
Author(s) -
Piqueux Sylvain,
Christensen Philip R.
Publication year - 2012
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 - 10.1029/2012gl053352
Subject(s) - regolith , martian , infrared , albedo (alchemy) , planetary surface , martian surface , thermal , geometric albedo , geology , astrobiology , atmospheric sciences , geophysics , mars exploration program , astronomy , physics , meteorology , photometry (optics) , art , stars , performance art , art history
We present visible and thermal infrared observations of the Martian surface acquired during three Phobos transits. Observations show a decrease of up to ∼20% of the reflected solar energy, consistent with the fraction of the Sun disk eclipsed by Phobos, and no measurable surface cooling. Thermal modeling indicates that the top millimeter of the regolith has a thermal inertia larger than 100 J m −2 K −1 s −1/2 regardless of the surface morphology, and is consistent with TES regional thermal inertia values derived from diurnal cycles (e.g. ∼200 J m −2 K −1 s −1/2 ). The thermophysical properties of the top millimeter of the regolith exclude the presence of widespread thermally‐thick dust layers, are consistent with those of the diurnal skin depths at TES and THEMIS spatial resolutions, are in accordance with high‐resolution images of the surface showing no surface mantling, with General Circulation Model results, thermally derived rock abundance values, albedo, and spectroscopic data.