The solar system as we know it formed about 4.6 billion years ago as fields of interstellar dust orbiting the sun aggregated into planets and smaller objects. Presolar dust particles no longer exist in the inner solar system, as they were long ago destroyed, reformed, and reaggregated in multiple phases. From the vantage of such a long period of time, astronomers can only make inferences about its composition and the processes that led to the solar system’s present configuration, bringing to bear advanced instruments on Earth, in orbit, and in deep space to collect evidence.