Physical properties of lunar craters  

作　　者：Maitri P. Joshi Kushal R Bhatt Rajmal Jain 

机构地区：[1]Shri Maneklal M.Patel Institute of Sciences and Research,Kadi Sarva Vishwavidhyalaya,Gandhinagar-382015,India

出　　处：《Research in Astronomy and Astrophysics》2017年第3期23-38,共16页天文和天体物理学研究（英文版）

摘　　要：The surface of the Moon is highly cratered due to impacts of meteorites, asteroids, comets and other celestial objects. The origin, size, structure, age and composition vary among craters. We study a total of 339 craters observed by the Lunar Reconnaissance Orbiter Camera （LROC）. Out of these 339 craters, 214 craters are known （named craters included in the IAU Gazetteer of Planetary Nomenclature） and 125 craters are unknown （craters that are not named and objects that are absent in the IAU Gazetteer）. We employ images taken by LROC at the North and South Poles and near side of the Moon. We report for the first time the study of unknown craters, while we also review the study of known craters conducted earlier by previous researchers. Our study is focused on measurements of diameter, depth, latitude and longitude of each crater for both known and unknown craters. The diameter measurements are based on considering the Moon to be a spherical body. The LROC website also provides a plot which enables us to measure the depth and diameter. We found that out of 214 known craters, 161 craters follow a linear relationship between depth （d） and diameter （D）, but 53 craters do not follow this linear relationship. We study physical dimensions of these 53 craters and found that either the depth does not change significantly with diameter or the depths are extremely high relative to diameter （conical）. Similarly, out of 125 unknown craters, 78 craters follow the linear relationship between depth （d） and diameter （D） but 47 craters do not follow the linear relationship. We propose that the craters following the scaling law of depth and diameter, also popularly known as the linear relationship between d and D, are formed by the impact of meteorites having heavy metals with larger dimension, while those with larger diameter but less depth are formed by meteorites/celestial objects having low density material but larger diameter. The craters with very high depth and with very small diameter are perhThe surface of the Moon is highly cratered due to impacts of meteorites, asteroids, comets and other celestial objects. The origin, size, structure, age and composition vary among craters. We study a total of 339 craters observed by the Lunar Reconnaissance Orbiter Camera （LROC）. Out of these 339 craters, 214 craters are known （named craters included in the IAU Gazetteer of Planetary Nomenclature） and 125 craters are unknown （craters that are not named and objects that are absent in the IAU Gazetteer）. We employ images taken by LROC at the North and South Poles and near side of the Moon. We report for the first time the study of unknown craters, while we also review the study of known craters conducted earlier by previous researchers. Our study is focused on measurements of diameter, depth, latitude and longitude of each crater for both known and unknown craters. The diameter measurements are based on considering the Moon to be a spherical body. The LROC website also provides a plot which enables us to measure the depth and diameter. We found that out of 214 known craters, 161 craters follow a linear relationship between depth （d） and diameter （D）, but 53 craters do not follow this linear relationship. We study physical dimensions of these 53 craters and found that either the depth does not change significantly with diameter or the depths are extremely high relative to diameter （conical）. Similarly, out of 125 unknown craters, 78 craters follow the linear relationship between depth （d） and diameter （D） but 47 craters do not follow the linear relationship. We propose that the craters following the scaling law of depth and diameter, also popularly known as the linear relationship between d and D, are formed by the impact of meteorites having heavy metals with larger dimension, while those with larger diameter but less depth are formed by meteorites/celestial objects having low density material but larger diameter. The craters with very high depth and with very small diameter are perh

关 键 词：MOON METEORITES METEORS meteoroids- planets and satellites： surfaces 

分 类 号：P184[天文地球—天文学]