"As a planet, Pluto has always been on oddball. Its composition is like a comet’s. Its elliptical orbit is tilted 17 degrees from the orbits of the other planets...But Pluto continued to be called a planet, because there was nothing else to call it. Then, in 1992, astronomers found the first Kuiper Belt object. Now they have found hundreds of additional chunks of rock and ice beyond Neptune, including 70 that share orbits similar to Pluto’s, the so called Plutino....A diagram is titled “To be, or not to be, a Planet”, showing Pluto midway point between the planets Earth and Mercury on one side and the not-planets Ceres and 2000 EB 173 on the other; its label stating that “Pluto is bigger than minor planets and has an atmosphere” and yet “Pluto has an unusual orbit and is made largely of ice.”"