Boulder Fall Activity in the Jezero Crater, Mars. Issue 23 (1st December 2020)

• Record Type: Journal Article
• Authors: Sinha, R. K.; Rani, A.; Conway, S. J.; Vijayan, S.; Basu Sarbadhikari, A.; Massé, M.; Mangold, N.; Bhardwaj, Anil
• Is Part Of: Geophysical research letters. Volume 47:Issue 23(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-01
• Subjects: Jezero -- Mars 2020 -- rover -- boulder -- crater -- boulder track; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2020GL090362
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Jezero crater is the landing site for the Mars 2020 Perseverance rover. We report 63 boulder fall tracks within the crater using High‐Resolution Imaging Science Experiment (HiRISE) images. The boulder tracks have both fresh and faded morphologies similar to those reported elsewhere on Mars, but reported for the first time in Jezero crater. We combine observations from 16 boulder‐tracks on the western delta deposit with 47 in the surrounding regions to infer possible process(es) of boulder destabilization, which can be tested with rover observations. This newly found hazard should be taken into account for rover operations. Boulders associated with tracks are geologically "recent falls, " so it is possible that the surfaces of these boulders may provide an opportunity to sample material less exposed to radiation than other rocks at the martian surface and could be ideal targets to analyze for organics. Plain Language Summary: We have found tracks left by falling boulders within Jezero crater on Mars, which is the landing site of the Mars 2020 Perseverance rover. The boulder tracks are observed on the slopes of the delta deposits that the rover will explore, on the wall of Jezero crater and on the wall of an ~2 km diameter crater on the floor of Jezero crater. Boulders of a few meters in size have fallen down moderately steep slopes, moving distances from a few tens of meters to nearly a kilometer. The boulder tracks appear both fresh and degraded. The positions of the boulders and the appearance of the tracks have not been observed to change, but the simple existence of the tracks suggests that the boulder falls are recent and could be ongoing. Our results reveal a new location on Mars where boulder fall activity is observed and indicate a new hazard to be taken into account by the rover team. These recently fallen boulders may also have surfaces less exposed to radiation and could be ideal candidates for obtaining samples that could be analyzed for signs of ancient life. Such signs usually degrade rapidly with exposure to radiation. Key Points: We report on previously unrecognized boulder fall activity in Jezero crater—landing site of Mars 2020 Perseverance rover Hazardous boulders bigger (length >2.7 m) than the rover have recently fallen on the front of the western delta deposits within the crater Recently fallen boulders may have freshly exposed surfaces, which can be ideal targets for astrobiological investigations by the rover