Astronomy by microscope

Abstract

Although meteorites have the external appearance of either a stone that might be found in a garden, or a piece of rusting metal, close examination of the components from which they are composed yields a rich harvest of information on all stages of evolution, almost from the Big Bang onwards. Analyses of different types of presolar grains from circumstellar and interstellar environments help to trace the chemical evolution of our galaxy and the populations of stars that contributed to the molecular cloud from which the Sun emerged. Chemistry within the molecular cloud is observed from organic species that have been isolated from primitive carbon-rich meteorites. These same species have been identified as being important in the processes that led to the initiation of life on Earth. Meteorites and components within them mark significant events in solar system evolution: planetary melting and differentiation, core formation, lunar bombardment and the extent and duration of volcanism and fluid flow on Mars.