  Small bodies, the unaccreted leftovers of planetary formation, are often
mistaken for the leftovers of planetary science in the sense that they are
everything else after the planets and their satellites (or sometimes just their
regular satellites) are accounted for. This mistaken view elides the great
diversity of compositions, histories, and present-day conditions and processes
found in the small bodies, and the interdisciplinary nature of their study.
Understanding small bodies is critical to planetary science as a field, and we
urge planetary scientists and our decision makers to continue to support
science-based mission selections and to recognize that while small bodies have
been grouped together for convenience, the diversity of these objects in terms
of composition, mass, differentiation, evolution, activity, dynamical state,
physical structure, thermal environment, thermal history, and formation vastly
exceeds the observed variability in the major planets and their satellites.
Treating them as a monolithic group with interchangeable members does a grave
injustice to the range of fundamental questions they address. We advocate for a
deep and ongoing program of missions, telescopic observations, R and A funding,
and student support that respects this diversity.
