The exhibit models, their accompanying text, and the overall layout of the Rose Center organized the...

The exhibit models, their accompanying text, and the overall layout of the Rose Center organized the principal contents of the solar system by objects of like properties, rather than as enumerations of planets and their moons. This decision landed Pluto among the growing number of icy objects found beyond Neptune, and left it unmentioned and out of view among our models for the rocky, terrestrial objects (Mercury, Venus, Earth, and Mars) and the gas giants (Jupiter, Saturn, Uranus, and Neptune). By this organization, we practically abandoned the concept of planet altogether.