The origin and evolution of our solar system has preoccupied human observers for centuries. Clues as to the nature of the early solar system can be found in primitive meteorites, whereas meteorites from the Moon and Mars provide direct samples of the surfaces and interiors of other bodies. Various spacecraft missions have explored the planets and satellites of the solar system, yielding information on surface composition, geological and geophysical evolution. Differences and similarities among the planets also enlighten our view of our home planet. Researchers within the department study solar system objects with a variety of approaches, including spacecraft data analysis, theoretical and computational modeling, and laboratory analysis. Development of new instruments for use on future terrestrial and planetary missions ensures the pace of discovery will continue.