Comets, asteroids, and protoplanets are remnants of the early universe that can help scientists piece together the formation of the solar system. The ESA’s Rosetta mission and NASA’s Dawn Mission are two recent expeditions exploring these vestiges. Nicolas Thomas, co-investigator of the Rosetta mission’s OSIRIS instrument, describes the surface of comet 76P and what this reveals about its formation. Marc Rayman, chief engineer and mission director of the Dawn Mission, explains what we might find at the protoplanets Vesta and Ceres.