A potential subsurface cavity in the continuous ejecta deposits of the Ziwei crater discovered by the Chang'E-3 mission

Ding, Chunyu1,2; Xiao, Zhiyong2,3; Su, Yan4,5

2021-02-17

10.1186/s40623-021-01359-7

EARTH PLANETS AND SPACE   影响因子和分区

1343-8832

1880-5981

In the radargram obtained by the high-frequency lunar penetrating radar onboard the Chang'E-3 mission, we notice a potential subsurface cavity that has a smaller permittivity compared to the surrounding materials. The two-way travel time between the top and bottom boundaries of the potential cavity is similar to 21 ns, and the entire zone is located within the continuous ejecta deposits of the Ziwei crater, which generally have similar physical properties to typical lunar regolith. We carried out numerical simulations for electromagnetic wave propagation to investigate the nature of this low-permittivity zone. Assuming different shapes for this zone, a comprehensive comparison between our model results and the observed radargram suggests that the roof of this zone is convex and slightly inclined to the south. Modeling subsurface materials with different relative permittivities suggests that the low-permittivity zone is most likely formed due to a subsurface cavity. The maximum vertical dimension of this potential cavity is similar to 3.1 m. While the continuous ejecta deposits of Ziwei crater are largely composed of pre-impact regolith, competent mare basalts were also excavated, which is evident by the abundant meter-scale boulders on the wall and rim of Ziwei crater. We infer that the subsurface cavity is supported by excavated large boulders, which were stacked during the energetic emplacement of the continuous ejecta deposits. However, the exact geometry of this cavity (e.g., the width) cannot be constrained using the single two-dimensional radar profile. This discovery indicates that large voids formed during the emplacement of impact ejecta should be abundant on the Moon, which contributes to the high bulk porosity of the lunar shallow crust, as discovered by the GRAIL mission. Our results further suggest that ground penetrating radar is capable of detecting and deciphering subsurface cavities such as lava tubes, which can be applied in future lunar and deep space explorations.Subsurface cavities of the Moon are the ideal natural shelter for future lunar explorations since they provide ideal insulation from cosmic radiation, meteoroid impacts, temperature fluctuations, etc. In this paper, we first report that a potential subsurface cavity with a height of similar to 3.1 m is revealed by the lunar penetrating radar onboard Chang'E-3 Yutu Rover

Chang'E-3 Lunar penetrating radar Moon Impact crater Porosity

SCI

英语

第一

Chinese Academy of Sciences[XDB41000000] ; National Natural Science Foundation of China[42004099,41773063,41525015,41830214,"D020201","D020202"] ; pre-research Project on Civil Aerospace Technologies - Chinese National Space Administration["D020201","D020202"] ; Key Laboratory of Lunar and Deep Space Exploration, Chinese Academy of Sciences["ldse201908","ldse202005"]

Geology

Geosciences, Multidisciplinary

WOS:000619221500001

SPRINGER

GEOSCIENCES

2-s2.0-85101086947

Web of Science

1.Southern Univ Sci & Technol, Dept Earth & Space Sci, Shenzhen 518055, Peoples R China
2.Sun Yat Sen Univ, Sch Atmospher Sci, Planetary Environm & Astrobiol Res Lab, Zhuhai 519000, Peoples R China
3.Chinese Acad Sci, Ctr Excellence Comparat Planetol, Hefei 230026, Peoples R China
4.Chinese Acad Sci, Key Lab Lunar & Deep Space Explorat, Natl Astron Observ, Beijing 100020, Peoples R China
5.Univ Chinese Acad Sci, Beijing 100049, Peoples R China

Ding, Chunyu,Xiao, Zhiyong,Su, Yan. A potential subsurface cavity in the continuous ejecta deposits of the Ziwei crater discovered by the Chang'E-3 mission[J]. EARTH PLANETS AND SPACE,2021,73(1).

Ding, Chunyu,Xiao, Zhiyong,&Su, Yan.(2021).A potential subsurface cavity in the continuous ejecta deposits of the Ziwei crater discovered by the Chang'E-3 mission.EARTH PLANETS AND SPACE,73(1).

Ding, Chunyu,et al."A potential subsurface cavity in the continuous ejecta deposits of the Ziwei crater discovered by the Chang'E-3 mission".EARTH PLANETS AND SPACE 73.1(2021).