Far-out Guide to the Icy Dwarf Planets (Far-out Guide to the Solar System)

Our solar system used to have nine planets. But recently, scientists ruled that Pluto was actually a "dwarf planet." So what exactly is a dwarf planet, how many of them are there, and how do scientists study and classify them? All the facts you need, and lots more, are included in this up-to-date book, featuring a center spread with fast facts.