Japan Geoscience Union Meeting 2023

Presentation information

[E] Oral

P (Space and Planetary Sciences ) » P-PS Planetary Sciences

[P-PS03] Small Solar System Bodies: New perspectives on the origin and evolution of the Solar System

Wed. May 24, 2023 1:45 PM - 3:15 PM 301A (International Conference Hall, Makuhari Messe)

convener:Tatsuaki Okada(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency), Fumi Yoshida(University of Occupational and Environmental Health, Japan), Sota Arakawa(Japan Agency for Marine-Earth Science and Technology), Ryota Fukai(Japan Aerospace Exploration Agency), Chairperson:Tatsuaki Okada(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency), Fumi Yoshida(University of Occupational and Environmental Health, Japan), Sota Arakawa(Japan Agency for Marine-Earth Science and Technology), Ryota Fukai(Japan Aerospace Exploration Agency)


1:45 PM - 2:00 PM

[PPS03-12] The Next-Generation Small-Body Sample Return: Comet Exploration Mission to Unveil the Origin of the Solar System

*Ryou Ohsawa1, Hiroyuki Kurokawa2, Yuri Shimaki3, Naoya Sakatani3, Ryota Fukai3, Eri Tatsumi4, Jun Aoki5, Yoko Kebukawa6, The Next Generation Small Body Sample Return Working Group (1.JASMINE Project, National Astronomical Observatory of Japan, 2.Earth-Life Science Institute, Tokyo Institute of Technology, 3.Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 4.Instituto de Astrofisica de Canarias, 5.Graduate School of Frontier Biosciences Osaka University, 6.Faculty of Engineering, Yokohama National University)

Keywords:Comets, 289P/Blanpain, Sample Return, Formation of the Solar System

Understanding the environment where the solar system formed will elucidate the origin of the solar system. Interstellar matters reflect the history of nucleosynthesis and processing in the Galaxy. Organic materials in the interstellar medium could be preserved through star and planet formation processes and incorporated into the primordial Earth. Knowing the sources of the materials that formed the solar system and their fractions remains to be addressed. Another open issue is the growing process of bodies in the primordial solar system. The building components of planetesimals remain to be understood. A comprehensive theory of solar system formation should take into account observations of protoplanetary disks and the history of elemental synthesis in the Galaxy.

In this presentation, we introduce our proposal for a planetary exploration mission for sample return of interior materials and inspection of the internal structure of a comet nucleus. Present samples of presolar grains are limited and possibly processed and biased by size sorting. We excavate unaltered primordial ingredients of the solar system under the reaccumulated layer of a comet nucleus both for sample return and in-situ analysis. The void structure of comet nuclei will determine whether comets or icy planetesimals were hierarchically formed. We plan to use a bistatic radar system or seismometer to inspect the inner structure of the comet nucleus. The current mission design and expected payloads will be presented with 289P/Blanpain as a provisional target.

The proposed mission may address open problems in comet observation. Material compositions may vary with depth, possibly related to the origins of some observational diversities and correlations, for example, the D/H ratio correlation with the comet activity. An excavation experiment may create a new active region, providing an opportunity for coordinated observations with ground-based or space-borne telescopes. Discussions about the mission are ongoing. Contributions, such as proposals for backup objects and new instruments, would be greatly appreciated.