DOI: 10.1029/2018JE005668
Scopus记录号: 2-s2.0-85052804997
论文题名: Unravelling the Mystery of Lunar Anomalous Craters Using Radar and Infrared Observations
作者: Fa W. ; Eke V.R.
刊名: Journal of Geophysical Research: Planets
ISSN: 21699097
出版年: 2018
卷: 123, 期: 8 起始页码: 2119
结束页码: 2137
语种: 英语
英文关键词: anomalous crater
; circular polarization ratio
; crater evolution
; ice deposits
; rock abundance
英文摘要: In Miniature Radio Frequency (Mini-RF) radar images, anomalous craters are those having a high circular polarization ratio (CPR) in their interior but not exterior to their rims. Previous studies found that most CPR-anomalous craters contain permanently shadowed regions and that their population is overabundant in the polar regions. However, there is considerable controversy in the interpretation of these signals: Both water ice deposits and rocks/surface roughness have been proposed as the source of the elevated CPR values. To resolve this controversy, we have systematically analyzed >4,000 impact craters with diameters between 2.5 and 24 km in the Mini-RF radar image and Diviner rock abundance (RA) map. We first constructed two controlled orthorectified global mosaics using 6,818 tracks of Mini-RF raw data and then analyzed the correlations between radar CPR and surface slope, RA, and depth/diameter ratios of impact craters. Our results show that CPR-anomalous craters are distributed relatively uniformly across the lunar surface, with no apparent difference in CPR between the polar, potentially icy, and nonpolar, not icy, craters. Most CPR-anomalous craters are relatively young with a large depth/diameter ratio, and they actually represent an intermediate stage of crater evolution. Comparison with a two-component radar scattering model suggests that rocks and surface roughness are major contributors to the observed CPR values. Using craters of 4.7–22 km in diameter with known ages, we find that craters spend up to 120 Ma with a high exterior RA, and ∼3 Ga in the CPR-anomalous phase. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113303
Appears in Collections: 气候减缓与适应
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作者单位: Institute of Remote Sensing and Geographical Information System, Peking University, Beijing, China; Lunar and Planetary Science Laboratory, Macau University of Science and Technology, Macau; Institute for Computational Cosmology, Department of Physics, Durham University, Durham, United Kingdom
Recommended Citation:
Fa W.,Eke V.R.. Unravelling the Mystery of Lunar Anomalous Craters Using Radar and Infrared Observations[J]. Journal of Geophysical Research: Planets,2018-01-01,123(8)