JpGU-AGU Joint Meeting 2017

講演情報

[EE] 口頭発表

セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS02] [EE] Small Bodies: Exploration of the Asteroid Belt and the Solar System at Large

2017年5月22日(月) 10:45 〜 12:15 103 (国際会議場 1F)

コンビーナ:eleonora ammannito(University of California Los Angeles)、中本 泰史(東京工業大学)、安部 正真(宇宙航空研究開発機構宇宙科学研究所)、Christopher T Russell(University of California Los Angeles)、渡邊 誠一郎(名古屋大学大学院環境学研究科地球環境科学専攻)、座長:Davidsson Bjorn(NASA Jet Propulsion Laboratory)

11:30 〜 11:45

[PPS02-28] A Mobile Asteroid Surface Scout (MASCOT) on board the Hayabusa 2 Mission to the near
Earth asteroid (162173) Ryugu

*Ralf Jaumann1,2Jean Pierre Bibring3Karl Heinz Glaßmeier4Matthias Grott1Tra Mi Ho5Stefan Ulamec6Nicole Schmitz1Christian Krause6Uli Auster4David Hercik4Jens Biele6Alexander Koncz1Cedric Pilogret3Vincent Hamm3Hitoshi Kuninaka7Tatsu Okada7Makoto Yoshokawa7Seicoro Watanabe8Masaki Fuijmoto7Harald Michaelis1Tilman Spohn1 (1.German Aerospace Center DLR Berlin、2.Freie Univ. Berlin, Inst. of Geosciences, Berlin, Germany、3.Univ. de Paris Sud-Orsay, IAS, Orsay, France、4.Inst. of Geophysics, Univ. Braunschweig, Germany、5.DLR, Inst. of Space Systems, Bremen, Germany、6.DLR-MUSC, Linder Höhe, Cologne, Germany、7.ISASJAXA, Yoshinodai, Chuo, Sagamihara, Kanagawa, Japan、8.Dep. of Earth and Planetary Sciences, Nagoya Univ. Furo-cho Chikusa-ku, Nagoya, Japan)

キーワード:Hayabusa, Mascot, Ruygu

MASCOT is part of JAXA’s Hayabusa 2 asteroid sample return mission that has been launched to asteroid (162173) Ryugu (1,2,3) on Dec 3rd, 2014. It is scheduled to arrive at Ryugu in 2018, and return samples to Earth in 2020. The German Aerospace Center (DLR) developed the lander MASCOT with contributions from CNES (France) (2,3). Ryugu has been classified as a Cg-type (4), believed to be a primitive, volatile-rich remnant from the early solar system. Its visible geometric albedo is 0.07, its diameter 0.87 km (5). The thermal inertia indicates thick dust with a cm-sized, gravel-dominated surface layer (5,6). Ryugu shows a retrograde rotation with a period of 7.63 h. Spectral observations indicate iron-bearing phyllosilicates (1) on parts of the surface, suggesting compositional heterogeneity. MASCOT will enable to in-situ map the asteroid’s geomorphology, the intimate structure, texture and composition of the regolith (dust, soil and rocks), and its thermal, mechanical, and magnetic properties in order to provide ground truth for the orbiter remote measurements, support the selection of sampling sites, and provide context information for the returned samples (2,3). MASCOT comprises a payload of four scientific instruments: a camera, a radiometer, a magnetometer and a hyperspectral microscope (2,3,7,8). Characterizing the properties of asteroid regolith in-situ will deliver important ground truth for further understanding telescopic and orbital observations as well as samples of asteroids. MASCOT will descend and land on the asteroid and will change its position by hopping (3). This enables measurements during descent, at the touch-down positions, and during hopping. The first order scientific objectives for MASCOT are to investigate at least at one position: the geological context of the surface by descent imaging and far field in-situ imaging; the global magnetization by magnetic field measurements during descent and any local magnetization at the landing positions; the mineralogical composition and physical properties of the surface and near-surface material including minerals, organics and the detection of possible, near–surface ices; the surface thermal environment by measuring the asteroids surface temperature over the entire expected temperature range for a full day-night cycle; the regolith thermophysical properties by determining the surface emissivity and surface thermal inertia; the local morphology and in-situ structure and texture of the regolith including the rock size distribution and small-scale particle size distribution; the context of the observations performed by both, the instruments onboard the main spacecraft and the in situ measurements performed by MASCOT (‘cooperative observations’). Provide documentation and context of the samples and correlate the local context of the in situ analysis with the remotely sensed global data; the body constitution on local and/or global scales and constrain surface and possibly sub-surface physical properties; the context of the sample collected and returned by the main spacecraft by qualifying its generic value and processed/pristine state and thus support the laboratory analyses by indicating potential alteration during sampling, cruise, atmospheric entry and impact phases.
(1) Vilas, F., Astro. J. 1101-1105, 2008; (2) Jaumann, R., et al., SSR, 2016; (3) Ho, T.-M. et al., SSR, 2016. (4) Bus, S.J., Binzel, R.P. Icarus 158, 2002; (5) Hasegawa, T.G., et al., Astron. Soc. Japan 60, 2008; (6) T.G. Mueller, T.G., et al., 2011. (7) Hercik, D., et al. SSR 2016. (8) Grott, M., et al. SSR 2016.