  Ordinary chondrites (OCs) are by far the most abundant meteorites (80% of all
falls). Their origin has long been the matter of a heated debate. About thirty
years ago (e.g., Pellas 1988), it was proposed that OCs should originate from
S-type bodies (the most abundant asteroid spectral types in the inner part of
the asteroid belt), but the apparent discrepancy between S-type asteroid and OC
reflectance spectra generated what was known as the S-type--OC conundrum. This
paradox has gradually been resolved over the years. It is now understood that
space weathering processes are responsible for the spectral mismatch between
S-type bodies and OCs. Furthermore, both telescopic observations and the first
asteroid sample return mission (Hayabusa) indicate that most S-type bodies have
mineralogies similar to those of OCs. Importantly, the S-type/OC link, which
has remained sterile for more than 30 years, has been delivering fundamental
constraints on the formation and evolution of planetesimals over the recent
years.
