Comets as parent bodies of CI1 carbonaceous meteorites and possible habitats of ice-microbes

摘要

Recent studies of comets and cometary dust have confirmed the presence of biologically relevant organic moleculesalong with clay minerals and water ice. It is also now well established by deuterium/hydrogen ratios that the CI1carbonaceous meteorites contain indigenous extraterrestrial water. The evidence of extensive aqueous alteration of theminerals in these meteorites led to the hypothesis that water-bearing asteroids or comets represent the parent bodies ofthe CI1 (and perhaps CM2) carbonaceous meteorites. These meteorites have also been shown to possess a diverse arrayof complex organics and chiral and morphological biomarkers. Stable isotope studies by numerous independentinvestigators have conclusively established that the complex organics found in these meteorites are both indigenous andextraterrestrial in nature. Although the origin of these organics is still unknown, some researchers have suggested thatthey originated by unknown abiotic mechanisms and may have played a role in the delivery of chiral biomolecules andthe origin of life on Early Earth.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.