Speaker: Yi Xu

Affiliation: Macau University of Science and Technology

Academic title: Associate Professor

Abstract:

Much of the Martian surface is covered by a weathering layer (regolith or soil) produced by long-term surface processes such as impact gardening, eolian erosion, water weathering, and glacial modifications. China’s first Martian mission, Tianwen-1 (TW-1), employed the Mars Rover Penetrating Radar (RoPeR) to unveil the detailed structure of the regolith layer and assess its dielectric properties. The RoPeR radargram revealed the local regolith layer to be highly heterogeneous and geologically complex and characterized by structures that resemble partial or complete crater walls and near-surface impact lenses at a very shallow depth. An improved hyperbola methods is employed to obtain the dielectric constant distribution in the shallow surface layer of the TW-1 landing zone to a depth of up to 16 m. The high dispersion of both permittivity and loss tangent values along the traverse path indicates relatively heterogeneous material distribution on the landing site compared to the Moon.

Biography:

Yi Xu is currently an associate professor of the State Key Laboratory of lunar and planetary sciences at Macau University of Science and Technology (MUST). She obtained her PhD from the University of Pittsburgh in the US and then joined MUST in Macau. She was a visiting scholar at the University of California, Los Angeles in 2017. Her current research area is planetary surface processes and mainly focuses on subsurface stratigraphy and property inversion of subsurface materials based on the data of ground penetrating radar equipped on a rover or spaceborne radar of the ongoing Chinese missions. She is a member of the scientific team of the Chang'E series lunar missions and the Tianwen-1 martian mission. She has participated in the pre-study of the future lunar polar exploration mission.