An Inclusive Library for Quantitative Analysis of the Laser-induced Breakdown Spectra Acquired by the Zhurong Mars Rover

Abstract Laser-induced breakdown spectroscopy (LIBS) is a critical tool for geochemical analysis in planetary science due to its ability to remotely detect a broad range of elements at submillimeter spatial resolution. However, matrix effects and environmental complexities on Mars pose significant challenges to LIBS data calibration. ChemCam and SuperCam are the two LIBS instrument-bearing payloads previously mounted on NASA’s Curiosity and Perseverance rovers, respectively. Dedicated LIBS spectral databases of ChemCam and SuperCam have facilitated a series of scientific research. In 2021, the Zhurong rover successfully landed on Mars and conducted investigations in Utopia Planitia, revealing evidence of prolonged water activity. Although the Mars Surface Composition Detector (MarSCoDe) placed on the rover contains a LIBS instrument, its contribution has been less prominent among the various payloads due to the absence of a dedicated LIBS spectral database to aid in data interpretation. In this study, we constructed a comprehensive LIBS spectral database tailored for the MarSCoDe, leveraging its engineering qualification model under simulated Martian conditions. The library incorporates 322 samples, including Martian soil simulants mixed with gradients of hydrous minerals, evaporated salts, and life-essential elements. Multivariate regression models were developed and validated, demonstrating high accuracy for quantitative analysis of major elements. Comparative analyses revealed the complementarity of this library to ChemCam and SuperCam datasets. This resource enhances the capability of MarSCoDe to interpret hydrous minerals and supports cross-instrument data integration, advancing our understanding of Martian aqueous history and potential habitability.