Collecting Samples of Mars: The NASA Perseverance Rover’s role in Mars Sample Return

The NASA Mars 2020 Perseverance rover mission has been exploring Jezero Crater since landing on February 18, 2021. The purpose of the mission is to investigate the geology, evaluate past habitability, look for signs of ancient life, and collect a suite of scientifically compelling samples for potential future return to Earth – the latter as part of an international Mars Sample Return campaign.

Noachian-aged Jezero Crater was once the site of a delta-lake system with a high potential for habitability. Perseverance carries 38 identical sample tubes designed for rock core or regolith, and five “witness tubes” for characterizing contamination from the rover. As of the completion of the Crater Floor Campaign in mid-March, 2022, Perseverance has sealed 10 tubes: 8 rock cores (representing 4 distinct rocks, collected in pairs), one tube in which inadvertently no core was acquired but which does include a serendipitous sample of ambient atmosphere, and one witness tube – a tube designed to capture contamination from the spacecraft. Whereas a number of different origins for the crater floor rocks were postulated based on orbital data, the result of exploration by Perseverance demonstrates that the crater floor rocks have an igneous origin. These rocks were mapped into two formations: Seítah and Máaz. The rocks investigated and sampled in Seítah are olivine cumulates that have been altered by fluids. The Máaz formation consists of a series of lava flows that have experienced variable degrees of fluid interaction. The 8 rock cores collected from the crater floor have high potential to address several important objectives of Mars Sample Return, including the magmatic history of Mars, geochronology, water-rock interactions, and whether an environment conducive to life existed on the crater floor after these igneous rocks were emplaced.

As of May 2022, the Delta Front Campaign is underway, with the first ever sedimentary samples collected in the summer. This campaign seeks to characterize the geology of the lowermost rock units in the delta, and collect representative samples of sedimentary rocks that could be used to look for ancient biosignatures in labs on Earth – a key goal of the Mars Sample Return effort.

By the end of the Delta Front Campaign, it is expected that Perseverance will have collected several additional sedimentary samples, a regolith sample, and additional witness tubes. A subset of the samples collected are planned to be placed in a cache near the delta front. The set of samples on board the rover will be carried along and added to, during the exploration of Jezero Crater and beyond.