which was the first kbo to be discovered?
THE SOLAR SYSTEM WIKI. Pluto. 134340 Pluto, more commonly known simply as Pluto, is the second-largest known dwarf planet in the Solar System, and the tenth largest observed body directly orbiting the Sun. It orbits between 29 and 49 AU from the Sun, and was the first Kuiper Belt object (KBO) to be discovered.