11:15 〜 11:30
[PPS03-09] Constraining the source of heterogeneity between soluble and insoluble organic matter from different Hayabuasa2 return particles.
キーワード：Ryugu, Organic matter, Irradiation, Aqueous alteration, Asteroids
Primitive C-type asteroids, such as Ryugu, represent important extraterrestrial reservoirs of organic matter. Accordingly, Ryugu was chosen as the target of JAXA’s Hayabusa2 mission, in part because it held the promise of containing extraterrestrial organic matter [1-2]. Such organic matter is important because it records a number of key environments and their associated processes [2]. Such environments and processes include those from before the formation of the Solar System (e.g. interstellar environments), during its formation (e.g. protosolar nebula and protoplanetary disk environments) and all those that came after its formation (e.g. planetesimal accretion, aqueous alteration, impact events and continuous UV, solar wind and cosmic ray irradiation). All of these environments and their related process impart particular information to extraterrestrial organic matter and thus unravelling this puzzle is extremely difficult. Another aspect that makes understanding the formation and evolution of extraterrestrial organic matter difficult is the introduction of terrestrial contamination to meteorites that have fallen to Earth. Therefore, the advantage of the Hayabusa2 return samples, is that they are comparatively mostly pristine.
Previously several studies [1-4] have shown that different Ryugu particle contain different abundances and compositions of minerals, IOM and SOM. However, further work is needed to help reveal what processes are responsible for this heterogeneity. Here a multi-analytical approach is applied to further elucidate the different processes that have affected Ryugu extraterrestrial organic matter.
Raman Spectroscopy and FTIR spectroscopy were applied to study demineralized insoluble organic matter (IOM) residues. In particular, these techniques revealed information about the effects of irradiation that have altered the organic matter at the surface of Ryugu. Meanwhile, desorption electrospray ionization-Orbitrap-Mass spectrometry was used to map the soluble organic matter (SOM) on the surface of the samples and constrain potential spatial relationships with minerals or features, such as cracks and voids. Furthermore, the intensity and spatial distribution of the SOM, was important for understanding the effects of any potential irradiation processes for Ryugu particles that were determined to have originated from closer to the surface of Ryugu from their IOM and Ne isotopic signatures. Finally, ultrahigh performance liquid chromatography-OT-MS (UHPLC-OT-MS) was utilized to quantify the alkylpyridine components of SOM in the Ryugu particles and further evaluate whether irradiation processes, accretionary processes or aqueous alteration were responsible for causing the heterogeneity observed in the SOM and IOM between different Ryugu particles.
Overall, this study helps to constrain the effects of the different processes that have been recorded by the extraterrestrial organic matter found within Ryugu particles. This is important, firstly because organic matter can be used to help us better understand such processes. Secondly, because organic matter is essential for the origin of life within our solar system, and knowing more about the different environments and processes that can form and destroy the prebiotic molecules that comprise life, will allow for better predicting the places within our solar system and beyond where life could originate.
[1] C. Potiszil et al., Life, 13(7), 1448 (2023).
[2] Nakamura et al., Proc. Jap. Acad., Ser. B. 98, 6, 227–282 (2022).
[3] Potiszil et al., Nat. Commun., 14, 1482 (2023).
[4] Potiszil et al., Earth Planet. Sci. Lett., 653, 119205 (2025).
Previously several studies [1-4] have shown that different Ryugu particle contain different abundances and compositions of minerals, IOM and SOM. However, further work is needed to help reveal what processes are responsible for this heterogeneity. Here a multi-analytical approach is applied to further elucidate the different processes that have affected Ryugu extraterrestrial organic matter.
Raman Spectroscopy and FTIR spectroscopy were applied to study demineralized insoluble organic matter (IOM) residues. In particular, these techniques revealed information about the effects of irradiation that have altered the organic matter at the surface of Ryugu. Meanwhile, desorption electrospray ionization-Orbitrap-Mass spectrometry was used to map the soluble organic matter (SOM) on the surface of the samples and constrain potential spatial relationships with minerals or features, such as cracks and voids. Furthermore, the intensity and spatial distribution of the SOM, was important for understanding the effects of any potential irradiation processes for Ryugu particles that were determined to have originated from closer to the surface of Ryugu from their IOM and Ne isotopic signatures. Finally, ultrahigh performance liquid chromatography-OT-MS (UHPLC-OT-MS) was utilized to quantify the alkylpyridine components of SOM in the Ryugu particles and further evaluate whether irradiation processes, accretionary processes or aqueous alteration were responsible for causing the heterogeneity observed in the SOM and IOM between different Ryugu particles.
Overall, this study helps to constrain the effects of the different processes that have been recorded by the extraterrestrial organic matter found within Ryugu particles. This is important, firstly because organic matter can be used to help us better understand such processes. Secondly, because organic matter is essential for the origin of life within our solar system, and knowing more about the different environments and processes that can form and destroy the prebiotic molecules that comprise life, will allow for better predicting the places within our solar system and beyond where life could originate.
[1] C. Potiszil et al., Life, 13(7), 1448 (2023).
[2] Nakamura et al., Proc. Jap. Acad., Ser. B. 98, 6, 227–282 (2022).
[3] Potiszil et al., Nat. Commun., 14, 1482 (2023).
[4] Potiszil et al., Earth Planet. Sci. Lett., 653, 119205 (2025).