[P-CG21] Planetary Magnetosphere, Ionosphere, and Atmosphere

[PCG21-03] Scientific objectives of the LAPYUTA and current status of feasibility study

*Fuminori Tsuchiya¹, Go Murakami², Atsushi Yamazaki², Shingo Kameda³, Akifumi Nakayama³, Masahiro Ikoma⁴, Tomoki Kimura⁵, Chihiro Tao⁶, Ryoichi Koga⁷, Jun Kimura⁸, Kei Masunaga², Shotaro Sakai¹, Masami Ouchi^4,9, Masaomi Tanaka¹, Shin Toriumi², Kazuo Yoshioka⁹, Masaki Kuwabara³, Masato Kagitani¹ (1.Tohoku University, 2.ISAS/JAXA, 3.Rikkyo University, 4.NAOJ, 5.Tokyo University of Science, 6.NICT, 7.Nagoya University, 8.Osaka University, 9.The University of Tokyo)

Keywords:Atmospheres of Earth-type plants, Icy moons, Jupiter, Extraplanet atmosphere

Ultraviolet spectroscopy is one of the most powerful tools to cover a wide range of scientific fields, from planetary science to astronomy. Here, we propose a future UV space telescope, LAPYUTA (Life-environmentology, Astronomy, and PlanetarY Ultraviolet Telescope Assembly), selected as a candidate for JAXA’s 6th M-class mission in 2023. Launch is planned for the early 2030s. LAPYUTA will perform spectroscopic and imaging observations in the far ultraviolet spectral range (110-190 nm) with a large effective area (>300 cm2) and a high spatial resolution (0.1 arcsec). LAPYUTA's orbit is designed as an elliptical orbit with an apogee of about 2,000 km and a perigee of 1,000 km to avoid the influence of the geocorona when observing oxygen and hydrogen atoms and the Earth's radiation belt. LAPYUTA will accomplish the following four objectives, which are related to two scientific goals: understanding (1) the habitable environment and (2) the origin of structure and matter in the universe. Objective 1 focuses on the subsurface ocean environments of Jupiter's icy moons and the atmospheric evolution of the terrestrial planets. Objective 2 is to characterize the atmospheres and estimate the surface environment of exoplanets around the habitable zone by detecting their exospheric atmospheres. In cosmology and astronomy, Objective 3 will test whether the structures of present-day galaxies contain ubiquitous Lyα halos and reveal the physical origins of Lyα halos. Objective 4 elucidates the synthesis process of heavy elements from observations of ultraviolet radiation from hot gas immediately after neutron star mergers.