Somewhere Over the Rainbow

The study of meteorites has produced a wealth of information about these objects. Petrologic and chemical observations of meteorites have shown the presence of planetary differentiates and of undifferentiated aggregates resulting from nebular condensation and the interaction of these aggregates due to metamorphism. Equilibrium chemistry in a solar gas and in planetary environments has been an excellent guide to our studies. Studies by several groups have yielded remarkable discoveries about the early stages of planetary evolution and of precursor components from the solar nebula and from the interstellar medium (ISM).