Radar-Derived Properties of the InSight Landing Site in Western Elysium Planitia on Mars

  • Nathaniel E. Putzig
  • Gareth A. Morgan
  • Bruce A. Campbell
  • Cyril Grima
  • Isaac B. Smith
  • Roger J. Phillips
  • Matthew P. Golombek
Article

DOI: 10.1007/s11214-016-0322-8

Cite this article as:
Putzig, N.E., Morgan, G.A., Campbell, B.A. et al. Space Sci Rev (2016). doi:10.1007/s11214-016-0322-8

Abstract

We carried out an assessment of surface and subsurface properties based on radar observations of the region in western Elysium Planitia selected as the landing site for the InSight mission. Using observations from Arecibo Observatory and from the Mars Reconnaissance Orbiter’s Shallow Radar (SHARAD), we examined the near-surface properties of the landing site, including characterization of reflectivity, near-surface roughness, and layering. In the Arecibo data (12.6-cm wavelength), we found a radar-reflective surface with no unusual properties that would cause problems for the InSight radar altimeter (7-cm wavelength). In addition, the moderately low backscatter strength is indicative of a relatively smooth surface at \({\sim} 10\mbox{-cm}\) scales that is composed of load-bearing materials and should not present a hazard for landing safety. For roughness at 10–100 m scales derived from SHARAD data, we find relatively low values in a narrow distribution, similar to those found at the Phoenix and Opportunity landing sites. The power of returns at InSight is similar to that at Phoenix and thus suggestive of near-surface layering, consistent with a layer of regolith over bedrock (e.g., lava flows) that is largely too shallow (\({<}10\mbox{--}20~\mbox{m}\)) for SHARAD to discern distinct reflectors. However, an isolated area outside of the ellipse chosen in 2015 for InSight’s landing shows faint returns that may represent such a contact at depths of \({\sim} 20\mbox{--}43~\mbox{m}\).

Keywords

Radar observations Surface roughness Mars Landing site analysis InSight Arecibo Mars Reconnaissance Orbiter SHARAD 

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  • Nathaniel E. Putzig
    • 1
    • 2
  • Gareth A. Morgan
    • 3
  • Bruce A. Campbell
    • 3
  • Cyril Grima
    • 4
  • Isaac B. Smith
    • 1
    • 2
  • Roger J. Phillips
    • 5
    • 6
  • Matthew P. Golombek
    • 7
  1. 1.Department of Space StudiesSouthwest Research InstituteBoulderUSA
  2. 2.Planetary Science InstituteLakewoodUSA
  3. 3.Center for Earth and Planetary StudiesSmithsonian InstitutionWashingtonUSA
  4. 4.Institute for GeophysicsUniversity of TexasAustinUSA
  5. 5.Planetary Science DirectorateSouthwest Research InstituteBoulderUSA
  6. 6.McDonnell Center for the Space Sciences and Department of Earth and Planetary SciencesWashington UniversitySt. LouisUSA
  7. 7.Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaUSA

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