"Once every 248 Earth years, Pluto swings inside the orbit of Neptune. It stays there for twenty years. During those twenty years, Pluto is closer to the Sun than Neptune. During this period of time, like the other eight planets, Pluto's atmosphere undergoes a fundamental change in character, briefly developing an atmosphere. As methane and nitrogen frozen at the poles thaw. As it moves toward its farthest point from the Sun, Pluto's atmosphere freezes and falls back to the ground" (Dejoie & Truelove 2008).

These eccentricities further suggested that Pluto was really much more "like a new group of objects found in the outer solar system," called dwarf planets and not worthy of the status of the other eight (Inman, 2008, p.2). Still, many astronomers argued in favor of a more inclusive definition that would still retain Pluto's status as a planet. In fact, one radical proposal: "would have made...
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