Jezero crater is a ~45‐km impact crater on the margin of Isidis basin on Mars. Jezero is the landing site for NASA's Mars 2020 rover mission. The crater hosts a paleolake, and fluvio‐lacustrine deposits formed in this lake remain accessible to exploration. A dark‐toned deposit on the crater floor overlies light‐toned carbonate‐bearing deposits and has been interpreted as a lava flow. We determined the average thickness of this deposit at the margins to be ~13.0 ± 0.8 m. We analyzed the statistics of impact craters superposed on this deposit and estimated its model age as 2.6 ± 0.5 Ga in the Hartmann system, placing it most likely in the Early Amazonian. The error estimate here includes an estimate of the uncertainty associated with the crater counts. Acquisition, caching, and eventual return of a sample from this unit could provide an important calibration point for Mars crater chronology.

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20 21Near-future exploration of the Moon will likely be conducted with human-operated robotic assets. 22Previous studies have identified the Schrödinger basin, situated on the far side of the Moon, as a prime 23 target for lunar science and exploration where a significant number of the scientific concepts reviewed 24 by the National Research Council (NRC, 2007) can be addressed. In this study, two robotic mission 25 traverses within Schrödinger basin are proposed based on a 3 year mission plan in support of the 26 HERACLES human-assisted sample return mission concept. A comprehensive set of modern remote 27 sensing data (LROC imagery, LOLA topography, M 3 and Clementine spectral data) has been 28 integrated to provide high-resolution coverage of the traverses and to facilitate identification of 29 specific sample localities. We also present a preliminary Concept of Operations (ConOps) study based on 30 a set of notional rover capabilities and instrumental payload. An extended robotic mission to 31 Schrödinger basin will allow for significant sample return opportunities from multiple distinct geologic 32 terrains and will address multiple high-priority NRC (2007) scientific objectives. Both traverses will offer 33 the first opportunity to (i) sample pyroclastic material from the lunar farside, (ii) sample Schrödinger 34 impact melt and test the lunar cataclysm hypothesis, (iii) sample deep crustal lithologies in an uplifted 35 peak ring and test the lunar magma ocean hypothesis and (iv) explore the top of an impact melt sheet, 36 enhancing our ability to interpret Apollo samples. The shorter traverse will provide the first opportunity 37 to sample farside mare deposits, whereas the longer traverse has significant potential to collect SPA 38 impact melt, which can be used to constrain the basin-forming epoch. 39 40