Pluto in size of Charon and Pluto has prompted some astronomers to call it a double dwarf planet. The system is also unusual among planetary systems in that each is tidally locked to the other, which means that Pluto and Charon always have the same hemisphere facing each other. From any position on either body, the other is always at the same position in the sky, or always obscured. This also means that the rotation period of each is equal to the time it takes the entire system to rotate around its barycenter. In 2007, observations by the Gemini Observatory of
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