Pluto is still considered a "dwarf" or minor planet (of which there are at least 3 in our solar system), it has just lost status as one of the major planets around the sun. The Astronomical Society voted about 60% to 40% to declare Pluto a minor planet due to several things. It does not have an elliptical orbit around the sun and will pass through the orbits of its neighbors at times. It is also relatively small, but so is Mercury. It does have three small moons, but based on evidence, most astronomers consider Pluto to be a moon that has escaped the gravitational pull of Neptune in the distant past. At times, Pluto passes closer to the Sun than Neptune. The main reasons that Pluto is now considered a "dwarf planet" are its size and the fact that it passes through the orbit of Neptune. This is based on the new definition of planet by the IAU.