Sampling Mars: Geologic context and preliminary characterization of samples collected by the NASA Mars 2020 Perseverance Rover Mission

Abstract

The NASA Mars 2020 Perseverance Rover Mission has collected samples of rock, regolith, and atmosphere within the Noachian-aged Jezero Crater, once the site of a delta-lake system with a high potential for habitability and biosignature preservation. Between sols 109 and 1,088 of the mission, 27 sample tubes have been sealed, including witness tubes. Each sealed sample tube has been collected along with detailed documentation provided by the Perseverance instrument payload, preserving geological and environmental context. Samples representative of the stratigraphy within each of four campaigns have been collected: samples from the Crater Floor Campaign represent a suite of potentially petrogenetically related igneous rocks displaying variable degrees of aqueous alteration; samples from the Fan Front record fluvial to deltaic sediments formed by the transport and deposition of materials from the Jezero watershed; regolith samples from the Fan Front preserve material possibly representative of global dust as well as diverse, locally derived clasts; Upper Fan samples record the latest stages of aqueous activity within Jezero; and samples from the Margin Campaign preserve lacustrine, littoral, or possibly igneous processes that may have occurred early in the history of the crater. Along with anticipated samples from the older rocks within the rim of Jezero Crater, Perseverance promises to deliver a suite of samples preserving a diversity of formation environments and ages. Upon return to Earth and analysis in terrestrial laboratories, these samples would address longstanding questions pertaining to the geologic evolution of Mars, its habitability, and the potential for life outside the Earth.

Keywords: Jezero Crater; Mars; geology; sample return.

Fig. 1.

Map showing mission progress at the time of writing, superimposed on a geologic map of Jezero crater, after ref. . Rover traverse and waypoints shown with white line and dots, respectively; sampling locations shown with red crosses. Labeled black boxes show approximate extent of each campaign. Names of major units or formations encountered—or expected to be encountered—are labeled in white italics. Approximate location of images shown in Fig. 2 are denoted with a red star.

Fig. 2.

Images showing the local contexts of Crater Floor samples: (A) 2 to 3 m tall cliff exposures of widespread Máaz formation that locally define the NW-SE trending Artuby Ridge. Kodiak mesa sediments that lie stratigraphically above can be seen in the distance. Boundary with southern edge of Séítah formation lies to the Right side of image. (B) Layering in lower Máaz formation outcrops near southern and eastern side of Séítah. Bouldery, crater-retaining, upper Máaz formation outcrops can be seen in the distance. (C) Tabular ~10 cm thick beds of Séítah formation (Left) grade into more massive, but still locally layered Séítah formation outcrops (Right).

Fig. 3.

Stratigraphic columns for the Shenandoah formation at (A) Cape Nukshak, (B) Hawksbill Gap West, and (C) Hawksbill Gap East. See ref. for locations and other details. The Inset (D) shows the Mastcam-Z workspace image of the Skinner Ridge outcrop after sampling the Swift Run core. The tailings pile after sampling, as well as the 5 cm wide Thornton Gap abrasion patch, are visible. The inset (E) shows the tailings after sampling the Hazeltop core, and the 5 cm wide Berry Hollow abrasion patch.

Fig. 4.

Navcam image of the immobile megaripple Observation Mountain which contains the regolith sampling locations of Atmo_Mountain (Left) and Crosswind_Lake (Right). The rover performed a scuff to expose the subsurface material that likely makes up the majority of the sample, and analyses were performed of both the undisturbed surface, the wall of the wheel scuff, the wheel track, and the tailings pile from the scuff (see ref. for details). For scale, the rover wheel is 33.6 cm wide.

Fig. 5.

Images of core samples collected to date (cf., Table 1). All images from Cachecam with the exception of Atsah (core #8); a Mastcam-Z image is provided instead. Core diameter in each case is 13 mm. Witness tubes are not shown.

Fig. 6.

Traceability matrix between the samples collected by Perseverance and the community objectives for MSR [“iMOST Objectives” (5)]. ISRU = in situ resource utilization. Sample numbers correspond to the numbering provided in Table 1.