Lunar apex–antapex cratering asymmetry as an impactor recorder in the Earth–Moon system |
| |
Authors: | Tomokatsu Morota Jun’ichi Haruyama Chikatoshi Honda Yasuhiro Yokota Makiko Ohtake Muneyoshi Furumoto |
| |
Institution: | 1. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara 229-8510, Japan;2. Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan |
| |
Abstract: | The degree of apex–antapex cratering asymmetry of a synchronously rotating satellite primarily depends on the mean encounter velocity of impactors with respect to the planetary system and the orbital velocity of the satellite. This means that we can estimate the mean encounter velocity of impactors by observing the apex–antapex cratering asymmetry, if the relationship between these is known. To apply this technique to the Moon, we attempt to derive the relationship between the mean encounter velocity of impactors and the degree of the lunar cratering asymmetry as a function of time, considering the temporal variation in the lunar orbital velocity during the last 4.0 Gyr. We used the cratering asymmetry of Zahnle et al. Zahnle, K., Schenk, P., Sobieszczyk, S. et al. Differential cratering of synchronously rotating satellites by ecliptic comets. Icarus 153, 111–129, 2001] to obtain the relationship. Applying this relationship enables us to estimate the impactor’s velocity of the Earth–Moon system from an investigation of the spatial distribution of lunar craters. Furthermore, we re-evaluate the cratering asymmetry’s influence on lunar cratering chronology. |
| |
Keywords: | Cratering asymmetry Impactor Earth&ndash Moon system Near-Earth Objects Cratering chronology |
本文献已被 ScienceDirect 等数据库收录! |
|