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CHAPTER 9: Life Chooses Homochirality: The Role of Cosmic Dust in Chiral Selection

Abstract:

The origin of homochirality is still an open and intriguing question for understanding the chemical origin of life. The hypothesis of an extraterrestrial origin of biomolecular chiral homogeneity, through a mechanism of asymmetric photolysis in space, raised the question of the search for astronomical sources of ultraviolet circularly polarized light. Several sources were proposed but with no convincing results. A possible scenario is that amino acids formed and protected in the cavities of interstellar dust aggregates are exposed to asymmetric photolysis induced by an ultraviolet circularly polarized light generated in situ, due to geometry-induced light depolarization inside the cavities. The implications of these results for chiral selection in space are discussed.