Thermal History of Asteroid Parent Bodies Is Reflected in Their Metalorganic Chemistry

Abstract

Abstract Organo-magnesium compounds were shown to contribute significantly to the soluble carbon molecular complexity and diversity of meteorites, and their analysis increases our knowledge on carbon stabilization/sequestration processes in the asteroidal parent body. Here we present a new group of sulfur-magnesium-carboxylates detected using ultra–high-resolution mass spectrometry in a variety of meteorites. These novel compounds show increased abundance correlated with the thermal history of the asteroid parent bodies. By comparing the soluble organic extracts of 44 meteorites having experienced variable post-accretion history, we describe distinct organic compound patterns of sulfur-magnesium-carboxylates in relation to their long- and short-duration thermal history. It is shown that the exceptional stability of these molecules enables survival of carbon under harsh thermal extraterrestrial conditions, even in the vitrified fusion crust formed during entry into the Earth's atmosphere. Sulfur-magnesium-carboxylates augment our understanding of parent body proceedings with regard to carbon sequestration and speciation in space.