By IndyKids Staff

What’s the difference between a planet and any other body floating around in space? Officially, even astronomers (people who study matter in outer space) aren’t sure. In August, astronomers met and decided to change the definition of a planet. In fact, according to the declaration, a planet must orbit the sun, be of a perfectly round shape, and it must have had “cleared the neighborhood” around its orbit. Pluto is now considered a dwarf planet because it only fulfills the first two criteria.