Spectrophotometric properties of Martian soil at the landing area of the Tianwen–1 Zhurong rover

¹ State Key Laboratory of Solar Activity and Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing, China
² College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
³ Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France
⁴ State Key Laboratory of Remote Sensing and Digital Earth, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China
⁵ Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, China
⁶ Key Laboratory of Planetary Science and Frontier Technology, Chinese Academy of Sciences, Beijing 100029, China

^★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 21 November 2025
Accepted: 11 February 2026

Abstract

Context. The Navigation and Terrain Camera (NaTeCam) on board the Zhurong rover acquired extensive imaging data of the landing site under a wide range of phase angles, providing a unique opportunity to investigate the photometric properties of this area.

Aims. We aim to retrieve the photometric and microphysical properties of the widely distributed soil units in the landing area, assess their implications for surface scattering behavior, and provide new ground-truth photometric constraints for this region.

Methods. We extracted phase curves from five Martian-day datasets, corrected them for diffuse skylight using the DISORT (DIScrete Ordinates Radiative Transfer) radiative transfer model, and inverted the photometric parameters by coupling the Hapke radiative transfer model with a parallel Monte Carlo approach.

Results. The soils exhibit backscattering-dominated behavior, relatively high particle porosity and/or heterogeneous size distributions, and low macroscopic roughness. The phase reddening effect is also observed, with a maximum near 60°.

Conclusions. These photometric properties provide key ground-truth constraints for surface scattering models and enable more reliable quantitative spectral analyses of the Zhurong landing site and adjacent regions.