An image mosaic of Perseverance rover in Mars’ Jezero Crater showing sedimentary rocks that likely formed in a delta, as well as a circular patch of abraded rock that Perseverance has analysed (Image: NASA/JPL-Caltech/ASU/MSSS)
As a planet with an atmosphere, volcanic landforms, recorded seismic activity, and evidence for liquid water in its past, Mars continues to be a fascinating and key target for planetary science missions. The Perseverance rover, part of NASA’s Mars 2020 mission, has been collecting information about Mars’ surface since February 2021. The rover’s main aims are to search for biosignatures, indicative of possible past life on Mars, and collect samples of rock and regolith that can be returned to Earth, hopefully in the next decade. Until then, Perseverance can conduct in-situ analyses of Martian material, allowing researchers to begin answering fundamental questions about Mars’ geological history and whether life has or could exist there.
Justin Simon at the NASA Johnson Space Center, Texas, USA, and colleagues from nearly 50 different institutions report on in-situ measurements of core samples collected by Perseverance from the floor of Jezero Crater. Using an instrument called PIXL (Planetary Instrument for X-ray Lithochemistry), familiar rock-forming minerals, such as pyroxene, olivine, and feldspar, are identified.
Evidence for aqueous alteration is also observed in the form of carbonates, sulphates, and iron oxide. Based on its textural, mineralogical, and geochemical observations, the team concludes that the samples represent igneous lithologies, possibly from a lava flow.
These samples represent a key landmark in Martian science: they are the first Martian samples that have a known geological context. The confirmation of aqueous alteration, therefore hydrological activity in Jezero Crater, strengthens our understanding of this important study site.
If these Martian samples can be successfully returned to Earth, researchers will be able to determine their age, allowing them to constrain
the timings of the emplacement of the lava flow, which gives us information about Martian magmatism, and the aqueous activity. This in turn will shed light on the hydrological history of Jezero Crater, and hence the past habitability of Mars.
Marissa Lo
Details
J. Geophys. Res. (2023 In Press); doi.org/10.1029/2022JE007474
