TY - JOUR

T1 - In Situ and Orbital Stratigraphic Characterization of the InSight Landing Site - A Type Example of a Regolith-Covered Lava Plain on Mars

AU - Warner, N. H.

AU - Golombek, M. P.

AU - Ansan, V.

AU - Marteau, E.

AU - Williams, N.

AU - Grant, J. A.

AU - Hauber, E.

AU - Weitz, C.

AU - Wilson, S.

AU - Piqueux, S.

AU - Mueller, N.

AU - Grott, M.

AU - Spohn, T.

AU - Pan, L.

AU - Schmelzbach, C.

AU - Daubar, I. J.

AU - Garvin, J.

AU - Charalambous, C.

AU - Baker, M.

AU - Banks, M.

N1 - Funding Information: Warner's contribution was supported through the NASA Participating Scientist program under Grant 80NSSC18K1624. Grant, Wilson, and Weitz's contributions were supported through the NASA Participating Scientist program under Grant 80NSSC18K1625. A portion of the work was also supported by the InSight Project at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. We are especially grateful to the Mars Reconnaissance Orbiter HiRISE (University of Arizona) and CTX (Malin Space Science Systems) imaging teams for their high‐quality data and hard work acquiring InSight‐related orbital imagery. We would like to thank Larry Crumpler and Horton Newsom for their thorough and helpful reviews. This is InSight Contribution Number 171. Funding Information: Warner's contribution was supported through the NASA Participating Scientist program under Grant 80NSSC18K1624. Grant, Wilson, and Weitz's contributions were supported through the NASA Participating Scientist program under Grant 80NSSC18K1625. A portion of the work was also supported by the InSight Project at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. We are especially grateful to the Mars Reconnaissance Orbiter HiRISE (University of Arizona) and CTX (Malin Space Science Systems) imaging teams for their high-quality data and hard work acquiring InSight-related orbital imagery. We would like to thank Larry Crumpler and Horton Newsom for their thorough and helpful reviews. This is InSight Contribution Number 171. Publisher Copyright: © 2022 The Authors.

PY - 2022

Y1 - 2022

N2 - The InSight lander rests on a regolith-covered, Hesperian to Early Amazonian lava plain in Elysium Planitia within a ∼27-m-diameter, degraded impact crater called Homestead hollow. The km to cm-scale stratigraphy beneath the lander is relevant to the mission's geophysical investigations. Geologic mapping and crater statistics indicate that ∼170 m of mostly Hesperian to Early Amazonian basaltic lavas are underlain by Noachian to Early Hesperian (∼3.6 Ga) materials of possible sedimentary origin. Up to ∼140 m of this volcanic resurfacing occurred in the Early Amazonian at 1.7 Ga, accounting for removal of craters ≤700 m in diameter. Seismic data however, suggest a clastic horizon that interrupts the volcanic sequence between depths of ∼30 and ∼75 m. Meter-scale stratigraphy beneath the lander is constrained by local and regional regolith thickness estimates that indicate up to 10–30 m of coarse-grained, brecciated regolith that fines upwards to a ∼3 m thick loosely-consolidated, sand-dominated unit. The maximum depth of Homestead hollow, at ∼3 m, indicates that the crater is entirely embedded in regolith. The hollow is filled by sand-size eolian sediments, with contributions from sand to cobble-size slope debris, and sand to cobble-size ejecta. Lander-based observations indicate that the fill at Homestead hollow contains a cohesive layer down to ∼10–20 cm depth that is visible in lander rocket-excavated pits and the HP3 mole hole. The surface of the landing site is capped by a ∼1 to 2 cm-thick loosely granular, sand-sized layer with a microns-thick surficial dust horizon.

AB - The InSight lander rests on a regolith-covered, Hesperian to Early Amazonian lava plain in Elysium Planitia within a ∼27-m-diameter, degraded impact crater called Homestead hollow. The km to cm-scale stratigraphy beneath the lander is relevant to the mission's geophysical investigations. Geologic mapping and crater statistics indicate that ∼170 m of mostly Hesperian to Early Amazonian basaltic lavas are underlain by Noachian to Early Hesperian (∼3.6 Ga) materials of possible sedimentary origin. Up to ∼140 m of this volcanic resurfacing occurred in the Early Amazonian at 1.7 Ga, accounting for removal of craters ≤700 m in diameter. Seismic data however, suggest a clastic horizon that interrupts the volcanic sequence between depths of ∼30 and ∼75 m. Meter-scale stratigraphy beneath the lander is constrained by local and regional regolith thickness estimates that indicate up to 10–30 m of coarse-grained, brecciated regolith that fines upwards to a ∼3 m thick loosely-consolidated, sand-dominated unit. The maximum depth of Homestead hollow, at ∼3 m, indicates that the crater is entirely embedded in regolith. The hollow is filled by sand-size eolian sediments, with contributions from sand to cobble-size slope debris, and sand to cobble-size ejecta. Lander-based observations indicate that the fill at Homestead hollow contains a cohesive layer down to ∼10–20 cm depth that is visible in lander rocket-excavated pits and the HP3 mole hole. The surface of the landing site is capped by a ∼1 to 2 cm-thick loosely granular, sand-sized layer with a microns-thick surficial dust horizon.

KW - duricrust

KW - Elysium Planitia

KW - InSight

KW - Mars

KW - regolith

KW - stratigraphy

U2 - 10.1029/2022JE007232

DO - 10.1029/2022JE007232

M3 - Journal article

AN - SCOPUS:85128762284

VL - 127

JO - Journal of Geophysical Research: Solid Earth

JF - Journal of Geophysical Research: Solid Earth

SN - 0148-0227

IS - 4

M1 - e2022JE007232

ER -