Definition of planet In the original draft proposal, an exception was made for Pluto and its largest satellite, Charon, which possess a barycenter outside the volume of either body. The initial proposal classified Pluto–Charon as a double planet, with the two objects orbiting the Sun in tandem. However, the final draft made clear that, even though they are similar in relative size, only Pluto would currently be classified as a dwarf planet. However, some have suggested that the Moon nonetheless deserves to be called a planet. In 1975, Isaac Asimov noted that the timing of the Moon's orbit is in tandem with the
Geography of Pluto Geography of Pluto The geography of Pluto entails the delineation and characterization of regions on Pluto. Plutonian geography is mainly focused on what is called physical geography on Earth; that is, the distribution of physical features across Pluto and their cartographic representations. On 14 July 2015, the "New Horizons" spacecraft became the first spacecraft to fly by Pluto. During its brief flyby, "New Horizons" made detailed geographical measurements and observations of Pluto and its moons. Pluto may be defined as having retrograde rotation and an axial tilt of 60 degrees, or prograde rotation and a tilt of 120 degrees. Following