Nakagawa, H., S. L. England, A. Kumar, M. Benna, Y. Harada, S. Sakai, N. Terada, K. Seki, N. Yoshida (2024) Different behavior of density perturbations between dayside and nightside in the Martian thermosphere and the ionosphere associated with atmospheric gravity waves, J. Geophys. Res., accepted. Sakai, S., H. Nakagawa, J. Deighan, S. K. Jain, K. Masunaga, F. Tsuchiya, N. Terada, M. Mayyasi, N. M. Schneider, D. L. Mitchell, C. Mazelle, M. Benna, R. J. Lillis, G. Murakami, S. M. Curry, K. Seki (2024) C+ 133.5 nm emission mechanisms on Mars revealed by the MAVEN observations, Astrophysical J., accepted. Bernardi, P.,...

Figure. Diagram of the proposed Venus mesospheric water cycle mechanism to sustain the observed HDO and H2O VMR and HDO/H2O ratio increase with altitude. ©Mathieux et al. Thanks to observations by the Venus Express space probe of the European Space Agency (ESA), an international research group led by Arnaud Mahiuex, a researcher at the Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Hiroki Karyu, a PhD student, and Assoc. Prof. Hiromu Nakagawa, at this laboratory, has discovered an unexpected increase in the abundances of two water molecule variants – H2O and HDO – and their ratio HDO/H2O in Venus’ mesosphere. The...

Figure . Conceptual diagram of the process by which formaldehyde (H2CO) is formed in the atmosphere on ancient, warm Mars and converted into the material molecules of life in the ocean (©Shungo Koyama).   A research group led by Shungo Koyama, a PhD student, and Prof. Naoki Terada in this laboratory, estimated the amount of formaldehyde produced in the ancient Martian atmosphere using a photochemical model of the atmosphere, and showed that formaldehyde was continuously produced in the warm period of ancient Mars. The results of this study suggest that sugar, a material molecule of life represented by ribose, one...

Mason, J., M. R. Patel, M. Pajola, E. D. Cloutis, J. Alday, K. S. Olsen, C. Marriner, J. A. Holmes, G. Sellers, N. Thomas, M. Almeida, M. Read, H. Nakagawa, I. R. Thomas, B. Ristic, Y. Willame, C. Depiesse, F. Daerden, A. C. Vandaele, J. J. Lopez-Moreno, and G. Bellucci (2023). Ultraviolet and visible reflectance spectra of Phobos and Deimos as measured by the ExoMars-TGO/NOMAD-UVIS spectrometer. Journal of Geophysical Research: Planets, 128, e2023JE008002. https://doi.org/10.1029/2023JE008002 Nakamura, Y., F. Leblanc, N. Terada, S. Hiruba, I. Murata, H. Nakagawa, S. Sakai, S. Aoki, A. Piccialli, Y. Willame, L. Neary, A. C. Vandaele, K....

A research team led by Professor Shohei Aoki of the Department of Complex Science and Engineering, Graduate School of Frontier Sciences at the University of Tokyo and Project Researcher Tatsuya Yoshida of this laboratory has revealed that carbon monoxide in the Martian atmosphere is low in carbon-13*1 using observation data from the European Mars Explorer ExoMars Trace Gas Orbiter This is the main component of the Martian atmosphere. This is thought to be because carbon 12 is more selectively destroyed when carbon dioxide, the main component of the Martian atmosphere, is decomposed into carbon monoxide by solar radiation. Organic matter...

Yoshida, T., N. Terada, M. Ikoma, and K. Kuramoto (2022). Less effective hydrodynamic escape of H2-H2O atmospheres on terrestrial planets orbiting pre-main sequence M dwarfs. The Astrophysical Journal, 934, 137(11pp). https://doi.org/10.3847/1538-4357/ac7be7 Nakayama, A., M. Ikoma, and N. Terada (2022). Survival of Terrestrial N2-O2 Atmospheres in Violent XUV Environments through Efficient Atomic Line Radiative Cooling. The Astrophysical Journal, 937, 72(18pp). https://doi.org/10.3847/1538-4357/ac86ca Kamada, A., T. Kuroda, T. Kodama, Y. Kasaba, and N. Terada (2022). Evolution of ice sheets on early Mars with subglacial river systems. Icarus, 385, 115117. https://doi.org/10.1016/j.icarus.2022.115117 Masunaga, K., N. Terada, N. Yoshida, Y. Nakamura, T. Kuroda, K. Yoshioka, Y....

Yoshida, N., N. Terada, H. Nakagawa, D. A. Brain, S. Sakai, Y. Nakamura, M. Benna, and K. Masunaga (2021). Seasonal and dust-related variations in the dayside thermospheric and ionospheric compositions of Mars observed by MAVEN/NGIMS. J. Geophys. Res. Planets, 126, e2021JE006926. https://doi.org/10.1029/2021JE006926 Kamada, A., T. Kuroda, Y. Kasaba, N. Terada, and H. Nakagawa (2021). Global climate and river transport simulations of early Mars around the Noachian and Hesperian boundary. Icarus, 368, 114618. https://doi.org/10.1016/j.icarus.2021.114618 Sugimoto, N., Y. Fujisawa, H. Kashimura, K. Noguchi, T. Kuroda, M. Takagi, and Y.-Y. Hayashi (2021). Generation of gravity waves from thermal tides in the Venus atmosphere. Nature Communications,...

Yoshida, N., H. Nakagawa, N. Terada, J. S. Evans, N. M. Schneider, S. K. Jain, T. Imamura, J.-Y. Chaufray, H. Fujiwara, J. Deighan, and B. M. Jakosky (2020), Seasonal and latitudinal variations of dayside N2/CO2 ratio in the Martian thermosphere derived from MAVEN/IUVS observations, J. Geophys. Res. Planets, 125, https://doi.org/10.1029/2020JE006378. Nakagawa, H., A. Yamazaki, K. Enya, N. Fujishiro, N. Terada, and K. Seki (2020) Design for stray-light reduction to a Martian ionospheric imager, Applied Optics, 59, 32, https://doi.org/10.1364/AO.401523. Kuroda, T., A.S. Medvedev and E. Yiğit (2020), Gravity Wave Activity in the Atmosphere of Mars During the 2018 Global Dust Storm: Simulations...

Aoki, S., Vandaele, A. C., Daerden, F., Villanueva, G. L., Liuzzi, G., Thomas, I. R., Erwin, J. T., Trompet, L., Robert, S., Neary, L., Viscardy, S., Clancy, R. T., M. D. Smith, M. A. Lopez-Valverde, Hill, B., Ristic, B., Patel, M. R., Bellucci, G., J.-J. Lopez-Moreno, and the NOMAD team (2019) Water vapor vertical profiles on Mars in dust storms observed by TGO/NOMAD, J. Geophys. Res., 124, 3482-3497, https://doi.org/10.1029/2019JE006109. Ishi, D., K. Ishikawa, M. Numazawa, Y. Miyoshi, N. Terada, K. Mitsuda, T. Ohashi, and Y. Ezoe (2019), Suzaku detection of enigmatic geocoronal solar wind charge exchange event associated with coronal...

O. Korablev, A. C. Vandaele, F. Montmessin, A. A. Fedorova, A. Trokhimovskiy, F. Forget, F. Lefèvre, F. Daerden, I. R. Thomas, L. Trompet, J. T. Erwin, S. Aoki, S. Robert, L. Neary, S. Viscardy, A. V. Grigoriev, N. I. Ignatiev, A. Shakun, A. Patrakeev, D. A. Belyaev, J.-L. Bertaux, K. S. Olsen, L. Baggio, J. Alday, Y. S. Ivanov, B. Ristic, J. Mason, Y. Willame, C. Depiesse, L. Hetey, S. Berkenbosch, R. Clariquin, C. Queirolo, B. Beeckman, E. Neefs, M. R. Patel, G. Bellucci, J.-J. López-Moreno, C. F. Wilson, G. Etiope, L. Zelenyi, H. Svedhem, J. L. Vago, and The...