New criteria to identify Martian mantle material from Isidis impact

A recent study published in Communications Earth & Environment outlines new criteria for identifying material from the Martian lower crust and mantle that was excavated by the Isidis impact. The Isidis Planitia, a vast impact basin over 1,500 kilometers in diameter, was formed by a massive collision that excavated deep planetary material and deposited it in the northeast Syrtis region. This area later hosted the formation of the 49-kilometer-wide Jezero crater, where the NASA Mars 2020 rover Perseverance is currently collecting samples for return to Earth.

Using the iSALE shock physics hydrocode, researchers simulated the Isidis impact in both two and three dimensions to determine the origin and shock state of the ejecta. The simulations suggest that the impact could have excavated the Martian upper mantle and deposited it near Jezero. The study found that material shocked to pressures between 45 and 60 GPa is likely to originate from the mantle, offering a potential way for the Perseverance rover to distinguish it from other surface materials.

The research also outlines a strategy for future Mars missions to optimize the identification of mantle material during traverses. The findings could be critical for understanding the composition and evolution of Mars' interior. The study highlights the potential for future sample return missions to analyze these materials in greater detail, offering new insights into the planet's geological history.

The research team acknowledges the contributions of several scientists and developers of the iSALE simulation software, which was instrumental in conducting the impact simulations. The study was supported by funding from NASA's Earth and Space Science Fellowship and the Jet Propulsion Laboratory.