GSA Annual Meeting in Phoenix, Arizona, USA - 2019

Paper No. 246-10
Presentation Time: 10:20 AM


GOLOMBEK, Matthew P.1, WILLIAMS, Nathan R.2, WARNER, Nicholas H.3, DAUBAR, Ingrid1, PIQUEUX, Sylvain1, CHARALAMBOUS, Constantinos4, MUELLER, Nils5, WEITZ, Catherine M.6 and GRANT, John A.7, (1)Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, (2)Jet Propulsion Laboratory, California Institute of Technology, M/S 183-301, 4800 Oak Grove Dr., Pasadena, CA 91109, (3)Department of Geological Sciences, SUNY Geneseo, 1 College Circle, Geneseo, NY 14454, (4)Department of Electrical and Electronic Engineering, Imperial College, London, United Kingdom, (5)DLR Deutsches Zentrum für Luft- und Raumfahrt, Berlin, Germany, (6)Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719, (7)Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Independence Ave at 6th St. SW, Washington, DC 20560

Predictions made from analysis of remote sensing data leading up to selection of the InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) landing site indicated it would be safe for landing and would be generally similar to the Spirit landing site, which has relatively low rock abundance, is moderately dusty, and has a fragmented regolith over Hesperian basalts from impact and eolian processes. The safe landing of InSight indicates the radar altimeter worked correctly and the surface was load bearing as predicted from Arecibo radar analysis. The InSight landing site is generally similar to the Spirit landing site with moderate thermal inertia and intermediate to high albedo. Orbital and surface thermal inertia measurements are similar (~200 J m-2 K-1 s-1/2) and consistent with a surface dominated by fine sand and a moderately dusty surface, which is consistent with the reddish color of the landscape and the dust removed to create the dark spot from the landing thrusters. Rocks counted near the lander have size-frequency distributions similar to exponential rock abundance models used to describe rock populations for landing spacecraft for cumulative fractional areas of 1-4%. These rock abundance counts are consistent with expectations based on orbital HiRISE measurements and thermal differencing estimates and generally similar to the Phoenix and Spirit landing sites, including the high abundance of granules and pebbles. Estimates of slopes of the landing ellipse made in MOLA, SHARAD and HiRISE data at 100 m and 1-5 m length scales are similar to observations from the surface and generally similar to the Opportunity and Phoenix landing sites. The density and morphometry of secondary craters from Corinto, a very young rayed crater on Mars, are similar in HiRISE images and observations from the lander. Measurements of the onset diameter of rocky ejecta craters indicate that a near surface fragmented regolith is between 2.6 m and 3.9 m thick near the lander. The abundant soil filled craters or hollows are generally similar to those characterized by the Spirit rover at the Gusev cratered plains and consistent with a surface dominated by impact, mass wasting and eolian processes that built up an impact fragmented regolith overlying Hesperian basalts.