  It is often claimed that asteroids' sharing of orbits is the reason they were
re-classified from planets to non-planets. A critical review of the literature
from the 19th Century to the present shows this is factually incorrect. The
literature shows the term asteroid was broadly recognized as a subset of planet
for 150 years. On-going discovery of asteroids resulted in a de facto
stretching of the concept of planet to include the ever-smaller bodies.
Scientists found utility in this taxonomic identification as it provided
categories needed to argue for the leading hypothesis of planet formation,
Laplace's nebular hypothesis. In the 1950s, developments in planet formation
theory found it no longer useful to maintain taxonomic identification between
asteroids and planets, Ceres being the primary exception. At approximately the
same time, there was a flood of publications on the geophysical nature of
asteroids showing them to be geophysically different than the large planets.
This is when the terminology in asteroid publications calling them planets
abruptly plunged from a high level of usage where it had hovered during the
period 1801 - 1957 to a low level that held constant thereafter. This marks the
point where the community effectively formed consensus that asteroids should be
taxonomically distinct from planets. The evidence demonstrates this consensus
formed on the basis of geophysical differences between asteroids and planets,
not the sharing of orbits. We suggest attempts to build consensus around
planetary taxonomy not rely on the non-scientific process of voting, but rather
through precedent set in scientific literature and discourse, by which
perspectives evolve with additional observations and information, just as they
did in the case of asteroids.
