Japan Geoscience Union Meeting 2016

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International Session (Oral)

Symbol B (Biogeosciences) » B-AO Astrobiology & the Origin of Life

[B-AO01] Astrobiology: Origins, Evolution, Distribution of Life

Tue. May 24, 2016 1:45 PM - 3:15 PM A01 (APA HOTEL&RESORT TOKYO BAY MAKUHARI)

Convener:*Kensei Kobayashi(Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University), Akihiko Yamagishi(Tokyo University of Pharmacy and Life Science, Department of Molecular Biology), Masatoshi Ohishi(Astronomy Data Center, National Astronomical Observatory of Japan), Eiichi Tajika(Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo), Takeshi Kakegawa(Graduate School of Science, Tohoku University), Shigeru Ida(Department of Earth and Planetary Science, Graduate School of Science and Technology, Tokyo Institute of Technology), Mary Voytek(NASA Headquarter), Joseph Kirschvink(Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA), Chair:Masatoshi Ohishi(Astronomy Data Center, National Astronomical Observatory of Japan), Shigeru Ida(Department of Earth and Planetary Science, Graduate School of Science and Technology, Tokyo Institute of Technology)

1:45 PM - 2:00 PM

[BAO01-01] Methane and HDO/H2O in the Martian atmosphere studied by ultra-high spectral resolution

*Hiromu Nakagawa1, Shohei Aoki3, Hideo Sagawa4, Kosuke Takami1, Yasumasa Kasaba1, Isao Murata1, Guido Sonnabend6, Manuela Sornig7, Takeshi Sakanoi2, Masato Kagitani2, Kuhn Jeffrey8, Ritter Joseph8, Shoichi Okano2, Makoto Taguchi5 (1.Planetary Atmosphere Physics Laboratory, Department of Geophysics, Graduate School of Science, Tohoku University, 2.Planetary Plasma and Atmospheric Center, Graduate School of Science, Tohoku University, 3.Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di AstroFisica, 4.Faculty of Science, Kyoto Sangyo University, 5.Rikkyo University, 6.Radiometer Physics GmbH, 7.German Aerospace Center, 8.Institute for Astronomy, University of Hawaii, Advanced Technology Research Center)

Keywords:Methane, HDO/H2O, Heterodyne

The Mid-Infrared LAser Heterodyne Instrument (MILAHI), which operates onboard the dedicated Tohoku 60cm telescope (T60) at the summit of Mt. Haleakala, has been designed for investigating the trace gases (Methane, HDO/H2O, etc) in the terrestrial atmospheres, such as Mars and Venus. The limitation to detect such trace gases from the ground-based is mainly due to the difficulty of correcting the atmospheric absorptions in the Earth atmosphere. High spectral resolution of MILAHI (>10E6) enables to retrieve them without any ambiguity due to the reproduction of atmospheric spectra on Earth.
In this study, we focus on the detection of methane and HDO/H2O in the Martian atmosphere. As a local oscillator (LO), newly installed quantum cascade laser (QCL) nicely covers 7.7 micron wavelength for these molecules. It is the only IR heterodyne instrument that gives access to new spectral range as compared with previous instruments of this kind.
Because the facility/instrument is just becoming to be operational in these years, the first Mars campaign will be performed on Feb.-Mar. 2016, with large Doppler shift (~15 km/s) between Mars and Earth. Prediction of the radiative transfer model indicates that the determination with two- VSMOW precision could be obtained by 15-minute integration. Upper limit 100ppb of methane will also be determined by 32-hours integration.
Further continuous observations will help to constrain (i) the possibility of biological/geological activities in the current Martian atmosphere, and (ii) water cycle and its evolution on Mars.