A Pre-Landing Assessment of Regolith Properties at the InSight Landing Site

This article discusses relevant physical properties of the regolith at the Mars InSight landing site as understood prior to landing of the spacecraft. InSight will land in the northern lowland plains of Mars, close to the equator, where the regolith is estimated to be ≥3--5 m thick. These investigations of physical properties have relied on data collected from Mars orbital measurements, previously collected lander and rover data, results of studies of data and samples from Apollo lunar missions, laboratory measurements on regolith simulants, and theoretical studies. The investigations include changes in properties with depth and temperature. Mechanical properties investigated include density, grain-size distribution, cohesion, and angle of internal friction. Thermophysical properties include thermal inertia, surface emissivity and albedo, thermal conductivity and diffusivity, and specific heat. Regolith elastic properties not only include parameters that control seismic wave velocities in the immediate vicinity of the Insight lander but also coupling of the lander and other potential noise sources to the InSight broadband seismometer. The related properties include Poisson’s ratio, P- and S-wave velocities, Young’s modulus, and seismic attenuation. Finally, mass diffusivity was investigated to estimate gas movements in the regolith driven by atmospheric pressure changes. Physical properties presented here are all to some degree speculative. However, they form a basis for interpretation of the early data to be returned from the InSight mission.Additional co-authors: Nick Teanby and Sharon Keda

DARE Newsletter, Vol. 9, No. 1, Winter 2006

Quarterly newsletter of the Dictionary of American Regional EnglishContents: "On the Road in Kentucky" by Sharon Huizenga; "Funding Update" by David Simon; "Contributors to DARE in 2005"; "Staff Member Profile: Scot LaFaive

DARE Newsletter, Vol. 8, Nos. 2/3, Spring/Summer 2005

Quarterly newsletter of the Dictionary of American Regional EnglishContents: "On the Road in Virginia" by Sharon Huizenga; "Funding Update" by David Simon; "Notes and Quotes"; "Where Are They Now?: Tamara Milbourn"; "Coming in Volume V"; "Staff Member Profile: Sheila Y. Kolstad"; "DARE Staff Photo"; "DARE Showcased at International Meeting

DARE Newsletter, Vol. 13, No. 1, Winter 2010

Quarterly newsletter of the Dictionary of American Regional EnglishContents: "On the Road Again in Virginia" by Sharon Huizenga; "From the Chief Editor's Desk" by Joan Houston Hall; "Coming in Volume V"; "Contributors to DARE in 2009"; "Where Are They Now?: Sally Jacobs"; "UW Grad Wins Honor for Work with DARE