Pluto was demoted to a newly created category, "dwarf planet," in 2006, partly because of the discovery a year earlier of Eris, another icy body from Pluto's neighborhood.

冥王星在2006年被降格至一个新创造的类别，“矮行星”，部分原因是在那之前一年，在冥王星的轨道附近，一颗名叫厄里斯的冰态天体被发现。

youdao

Eris is real, but it is a dwarf planet similar to Pluto that will remain in the outer solar system; the closest it can come to Earth is about 4 billion miles.

行星厄里斯是真的，但它是一个和冥王星类似的矮行星，将继续待在太阳系外围；它最接近地球的位置有大约40亿英里。

youdao

So Pluto should be a planet, as should Eris and the dwarf planet Ceres (the largest body in the asteroid belt between Mars and Jupiter), as well as many other objects.

这样看来，冥王星应该属于行星，就像厄里斯和矮行星谷神星(火星和木星之间的小行星带里最大的天体)，以及许多其他的物体也应如此。

youdao

So Pluto should be a planet, as should Eris and the dwarf planet Ceres (the largest body in the asteroid belt between Mars and Jupiter), as well as many other objects.

这样看来，冥王星应该属于行星，就像厄里斯和矮行星谷神星(火星和木星之间的小行星带里最大的天体)，以及许多其他的物体也应如此。

youdao