[P-PS07] Formation and evolution of planetary materials in the Solar System

[PPS07-01] Detection of hexamethylenetetramine in carbonaceous meteorites and its role for chemical evolution

*Yasuhiro Oba¹, Yoshinori Takano², Hiroshi Naraoka³, Yoshihiro Furukawa⁴, Shogo Tachibana^5,6, Daniel P Glavin⁷, Jason P Dworkin⁷ (1.Institute of Low Temperature Science, Hokkaido University, 2.JAMSTEC, 3.Kyushu University, 4.Tohoku University, 5.University of Tokyo, 6.ISAS/JAXA, 7.NASA Goddard Space Flight Center)

Keywords:HMT, carbonaceous meteorites, chemical evolution

Hexamethylenetetramine (HMT, C₆H₁₂N₄), an organic molecule with a characteristic cage-like structure, is the most abundant product in the photolysis of interstellar ice analogues containing water, methanol, ammonia, etc, under astrophysically relevant conditions. However, despite such properties, HMT has never been detected in any extraterrestrial environments/materials so far. We have for the first time detected HMT in three carbonaceous meteorites (Murchison, Tagish Lake, and Murray) whose concentrations are equivalent to other meteoritic organic molecules such as amino acids. Since HMT can yield formaldehyde and ammonia, which are necessary for the formation of various meteoritic organic molecules such as amino acids and sugars, upon (hydro)thermal degradations on meteorite parent bodies, it should play a vital role for chemical evolution in the solar system. In addition, the detected HMT would have formed by photochemical reactions in the interstellar medium, suggesting that its formation predated the formation of the solar system.

[Ref.] Oba, Y., Takano, Y., Naraoka, H., Furukawa, Y., Glavin, D.P., Dworkin, J.P. and Tachibana, S. (2020) Extraterrestrial hexamethylenetetramine in meteorites-a precursor of prebiotic chemistry in the inner solar system.
Nature Communications, 11, Article number: 6243. doi: 10.1038/s41467-020-20038-x.