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

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