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Comparison of Dielectric Properties and Structure of Lunar Regolith at Chang'e‐3 and Chang'e‐4 Landing Sites Revealed by Ground‐Penetrating Radar
Author(s) -
Lai Jialong,
Xu Yi,
Zhang Xiaoping,
Xiao Long,
Yan Qi,
Meng Xu,
Zhou Bin,
Dong Zehua,
Zhao Di
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl084458
Subject(s) - regolith , ejecta , geology , impact crater , lunar mare , basalt , space weathering , lunar soil , weathering , radar , ground penetrating radar , geophysics , mineralogy , geomorphology , astrobiology , geochemistry , asteroid , physics , telecommunications , quantum mechanics , supernova , computer science
On 3 January 2019, the Chang'e‐4 (CE‐4) touched down on the Von Karman crater located inside the South Pole‐Aitken Basin, providing for the first time the opportunity for in situ measurements of the lunar regolith at the farside of the Moon. The CE‐4 ground penetrating radar reveals that fine‐grained regolith, coarse impact ejecta, and fractured bedrocks lie beneath the exploration path of the Yutu‐2 rover. The variations of regolith permittivity with depth and the radargrams indicate that the CE‐4 site has a fine‐grained regolith layer thickness of 11.1 m, which is about 1.3–3 times higher than the in situ measurement results at the Apollo and Chang'e‐3 (CE‐3) sites except for Apollo 16, possibly due to a faster weathering rate of ejecta deposits compared with coherent basalt substrates. The penetration depth of CE‐4 is about 2.85 times (in terms of round‐way delay) deeper than CE‐3, probably due to the differences in abundances of ilmenite and rocks in the regolith.