Pluto
Videos
Pluto is a dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Sun. It is the largest known
Clyde Tombaugh, in Kansas
Sputnik Planitia is covered with churning nitrogen ice "cells" that are geologically young and turning over due to convection.
A multispectral Visual Imaging Camera image of Pluto in enhanced color to bring out differences in surface composition
Regions where water ice has been detected (blue regions)
Planets beyond Neptune
Videos
Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began in the mid-19th century and continued at th
Percival Lowell, originator of the Planet X hypothesis
Jacques Babinet, an early proponent of a trans-Neptunian planet
Discovery image of Charon