M. C. De Sanctis
ABSTRACT
Main belt asteroids, which orbit the Sun primarily between Mars and Jupiter, are remnants of the original building materials of the planets that never accumulated enough mass to fully form. As such, they provide crucial insights into the formation and evolution of the Solar System. They may also hold important clues about the origin of life, since similar bodies could have delivered water and organic compounds to the early Earth.
Clear links between asteroids and meteorites have been established through a combination of multi-technique observations, theoretical modeling, in situ measurements, and sample return analyses. Data acquired by spacecraft have significantly advanced our understanding of these small bodies, revealing an extraordinary diversity in their physical properties and compositions, ranging from ice-rich materials to lunar-like and chondritic types.
Nearly all small bodies observed today—whether primitive or evolved—are the result of complex histories involving accretion and one or more episodes of catastrophic disruption.
These events have often led to the formation of asteroid families, groups of smaller bodies that share distinct and informative petrogenetic relationships.
This overview will examine current knowledge of asteroid properties, their connections to other populations across the Solar System, and will place particular emphasis on the two largest bodies, Vesta and Ceres, which have been explored by space missions.