Watch：Nov.10 Prof. Yi XU: The lunar and martian shallow subsurface structure and dielectric properties revealed by ground penetrating radar
Speaker: Prof. Yi XU
Macau University of Science and Technology (M.U.S.T.)
Nov.10
3PM GMT +8
Most surfaces on Mars and the Moon are covered by a weathering layer (regolith or soil). The properties and fine-resolution structure of the regolith layers in these two planetary bodies are the results of surface processes that developed over millions/billions of years. They are expected to differ greatly due to the effects of different atmospheric and gravity environments. Moreover, the martian regolith has undergone more complex geological activities, e.g. eolian, chemical and mechanical weathering by fluids, etc. in addition to the main process, impact gardening, which is also ubiquitous on the Moon.
Both Chinese martian and lunar rovers are equipped with a ground-penetrating radar (GPR) that can reveal high-resolution near-surface structural and dielectric characteristics using two different frequency channels. The detection range of the high-frequency channel is ~ 10 m, while the low-frequency one can probe deeper, down to hundreds of meters, to constrain the local geologic history.
In this talk, I will first introduce the observations and results of the GPR from the CE-3 mission that landed on Mare Imbrium on the lunar nearside. Next, I will review the results of the CE-4 GPR that has been surveying the floor of the von Kármán crater on the lunar farside. Finally, I will talk about the GPR results of China’s first martian mission, Tianwen-1 which touched down in the southern part of the Utopia Planitia.
About the speaker
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 also studying the geomorphologic features of landforms on the Mars and Earth. 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.
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