Lunar Landing Site Candidates Discussed In The Japan’s Science Community
In 2007, just 10 years ago, Japan launched the SELENE (Kaguya) mission. Since that time, Japan’s lunar science community has provided new information about the Moon based on the data from SELENE, often collaborating with researchers abroad. Based on new results from SELENE and other lunar explorers in this decade, several initiatives for landed exploration on the Moon are ongoing in Japan. The initatives are at various stages of development, including Project (approved for launch), Pre-Project, and detailed research activity. Here we will introduce some lunar landing site candidates proposed in Japan, and describe the current status of Japan’s lunar exploration. In Japan, there are two main types of proposed lunar exploration missions: science-oriented bottom-up ones, and politically-led ones which aim to advance the state of knowledge and technology needed to expand human activity and ultimately habitability in space. The bottom up mission SLLM (Smart Lander for Investigating the Moon) will be the first lunar lander of Japan, which is aiming for a scientifically interesting and technologically possible landing site. In parallel to the SLIM mission that has been approved for launch around 2020, several other landing sites are under consideration for future Japanese lunar exploration missions, such as: 1) young geologic units located on the Oceanus Procellarum: to validate the crater chronology current scheme and the history of lunar internal evolution by investigation of key elements such as Ti, REE, and even water. We may need mobility technology and sample return for more accurate age estimation. 2) SPA: to collect deep and ancient materials to improve our understanding of the Late Heavy Bombardment. We need landing technology capable of operating on the lunar Farside and a relay-communication method. The pin-point landing technology needed to enable this mission will be developed by the SLIM mission. Sample return from target sites in SPA is of high scientific priority. 3) subsurface caves: to acquire information regarding paleo magnetism, heat flow, fresh materials including endogenic volatiles, and key elements such as Ti and KREEP. Many new technologies are required for the challenging task of approaching a cave and exploring a dark and unknown space. The first mission may have to be a path-finder. 4) Sites of quasi-permanently illumination, of permanent shadow, protected by mini-magnetospheres, and in underground caves: these landing sites are all aimed to support human space exploration and habitation. Science will contribute to the achievement of this noble purpose by developing more accurate knowledge of the environment of and near the landing sites.