日本地球惑星科学連合2018年大会

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セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS08] 惑星科学

2018年5月21日(月) 09:00 〜 10:30 国際会議室(IC) (幕張メッセ国際会議場 2F)

コンビーナ:岡本 尚也(国立研究開発法人宇宙航空開発機構 宇宙科学研究所)、黒崎 健二(名古屋大学大学院 理学研究科 素粒子宇宙物理学専攻)、座長:諸田 智克(名古屋大学大学院 環境学研究科)、洪 鵬(千葉工業大学 惑星探査研究センター)

09:30 〜 09:45

[PPS08-09] ハビタブル惑星の形成を探る火星衛星探査計画MMX

*倉本 圭1川勝 康弘2藤本 正樹2玄田 英典3今村 剛4亀田 真吾5松本 晃治6宮本 英昭4諸田 智克7長岡 央8中村 智樹9小川 和律10大嶽 久志2尾崎 正伸2佐々木 晶11千秋 博紀12橘 省吾4寺田 直樹9臼井 寛裕3和田 浩二12渡邊 誠一郎7MMX study team (1.北海道大学、2.JAXA、3.東京工業大学、4.東京大学、5.立教大学、6.国立天文台、7.名古屋大学、8.早稲田大学、9.東北大学、10.神戸大学、11.大阪大学、12.千葉工業大学)

キーワード:火星、フォボス、ダイモス、惑星形成、火星衛星探査計画

JAXA’s Martian Moons eXploration (MMX) is a planned round-trip mission to the Martian moons to be launched in mid-2020’s. Currently, its conceptual studies are being proceeded as a pre-project of ISAS/JAXA. In this paper, we will report the present status of conceptual study for MMX.



The main science objectives of MMX are to reveal the origin of the Martian moons under debate among primitive asteroid capture and giant impact, and then to make a progress in our understanding of planetary system formation and primordial material transport around the border between the inner- and the outer-part of the early solar system. To achieve those science objectives, MMX will carry out close-up observations of the two moons and sample return from Phobos.



A set of mission instruments is going to be prepared to achieve major mission goals. A sampler system is studied for acquisition of more than 10 g of Phobos regolith samples. MEGANE (Neutron and Gamma-Ray Spectrometer), WAM (Wide Angle Multiband cameras), MacrOmega (Near IR Spectrometer), TL (TeLescope camera), LIDAR (LIght Detection And Ranging), CMDM (Circum-Martian Dust Monitor) and MSA (Mass Spectrum Analyzer) are specified as nominal science instruments. Some optional mission instruments are under discussion (a small surface science package, etc.). MEGANE and MacrOmega will be prepared by CNES and NASA under the participation of researchers from Japan.



Close-up sensing data will provide constraints for the elemental and mineralogical compositions of Phobos and Deimos, which are key parameters to clarify the origin of the two moons. Isotopic, elemental and mineralogical compositions of sample particles will be examined with chronological analysis to obtain unambiguous evidence for the moon’s origin and the cosmochemical nature of Phobos in the context of planet formation and Martian system evolution. These data are expected to tell us the birthplace and migration of Phobos until the capture event if capture origin is the case. Alternatively, the source region of the moon-forming giant impactor, the age and processes of the giant impact event, and the physico-chemical state of primordial Martian mantle will be clarified if the giant impact origin is the case. Survey and analyses (if available) of younger materials originated from Mars would provide us information on the evolutionary history of Mars. By applying onboard instruments for monitoring observations of Mars and the surrounding space, MMX will also aim to understand physical processes in circum-Martian environment and Mars atmosphere. This would enhance our views of evolution of Martian moons as well as the surface environmental transition of Mars.