� Small bodies are not geologically active � They provide �fossil� record of early solar system � Asteroids � Mostly from region between Mars and Jupiter � Left over small debris from accretion, never assembled into a large planet � Meteorites come mostly from asteroids � Comets � �Stored� on large elliptical orbits beyond planets � Thought to be �planetesimals� from Jovian planet region, almost ejected from solar system in its early history � Meteorites provide only samples besides Apollo � With sample in hand, can perform very detailed analysis: detailed chemistry; radioisotope age; other isotope info