HOW MANY PLANETS HAVE BEEN FOUND, AND HOW MANY MORE ARE OUT THERE?
IME WAS, THERE WERE ONLY nine known planets in the entire universe—the gaggle of worlds that orbit our sun. That number was reduced to eight in 2006, when the International Astronomical Union busted Pluto down to a dwarf planet. But even before Pluto was pink-slipped, the planetary census far deeper in space began to
