Proposed identification criteria of the Martian lower crust and mantle excavated by the Isidis impact.

Isidis Planitia is a > 1500 km diameter Martian impact basin1-4. The impact excavated material and deposited it in the northeast Syrtis region on which the 49-km diameter Jezero crater subsequently formed. The NASA Mars 2020 rover Perseverance is currently near Jezero crater5 collecting samples for eventual return to Earth. Here, we simulate the Isidis impact using the shock physics hydrocode impact-Simplified Arbitrary Lagrangian Eulerian (iSALE) both in two dimensional (2D) and three dimensional (3D) to determine the provenance and shock state of ejecta in this region. We find that the Isidis-forming impact can excavate the Martian upper mantle and deposit it near Jezero. Additionally, the excavated material shocked to 45-60 GPa is predominately sourced from the mantle, which may enable the Perseverance rover to distinguish it from other excavated deposits. Utilizing these hydrocode results, we describe a strategy for a possible future traverse to optimize identification of ejected mantle.