天文学家们知道冥王星和海王卫一拥有几乎相同的体积、质量和密度。
Astronomers know that Pluto and Triton have nearly the same size, mass, and density.
这里可以看见它的已知3个卫星：冥卫1，冥卫2，和冥卫3。 包括冥王星在内的一群物体，在海王星的凯伯带（数十亿颗在海王星轨道之外绕行的小型冰体构成的碟形带）之上，围绕着太阳的作盘形轨道运行。
Seen here with its three known moons, Charon, Nix, and Hydra, Pluto is a member of a group of objects that orbit in a disklike zone beyond the orbit of Neptune called the Kuiper belt.
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