Visible and thermal infrared observations of the Martian surface during three Phobos shadow transits
Article first published online: 14 NOV 2012
©2012. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 39, Issue 21, November 2012
How to Cite
2012), Visible and thermal infrared observations of the Martian surface during three Phobos shadow transits, Geophys. Res. Lett., 39, L21203, doi:10.1029/2012GL053352., and (
- Issue published online: 14 NOV 2012
- Article first published online: 14 NOV 2012
- Manuscript Accepted: 15 OCT 2012
- Manuscript Revised: 8 OCT 2012
- Manuscript Received: 31 JUL 2012
 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.