Chapter 3 - The Origin and Evolution of Organic Matter in Carbonaceous Chondrites and Links to Their Parent Bodies

Abstract

The nature of organic matter in meteorites reveals information about early solar system chemistry and the histories of parent bodies as recorded in the effects of physical and chemical processes that occurred over the past 4.5billion years. Asteroids and their fragments impact the Earth with ∼40million kg of material each year and contributed to the inventory of organics available for the origin of life. Analyses of primitive carbonaceous chondrites over the last five decades have revealed a major insoluble organic component, as well as a complex and highly diverse suite of soluble organic molecules that includes aliphatic and aromatic hydrocarbons, carboxylic acids, hydroxy acids, N-heterocycles, polyols, amino acids, amines, and many other molecules that have not yet been identified. Thermal and aqueous alteration in primitive asteroids played an important role in the formation and destruction organics, including amplification of l-amino acid and d-sugar acid enantiomeric excesses that may have contributed to the origin of homochirality in life on Earth.