The Sun is the hub of a huge rotating system consisting of nine planets, their satellites, and numerous small bodies, including asteroids, comets, and meteoroids.

太阳是一个巨大的旋转系统的中心，这个旋转系统由九大行星、它们的卫星和无数的小天体组成，包括小行星、彗星和流星体。

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Moving around the nucleus are extremely tiny particles, called electrons, which revolve around the nucleus in much the same way as the nine planets do around the sun.

围绕着原子核运动的是一些极其微小的粒子，称为电子，这些电子围绕着原子核旋转，正像九大行星围绕着太阳旋转一样。

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It seems that even if the IAU had kept Pluto's status as a planet, the classical theory of nine planets in the solar system would have had to be changed, but the other way around.

由此看来，即使国际天文学联合会保住冥王星的行星地位，经典的太阳系九大行星理论也仍然要改，只是改法相反而已。

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If the International Astronomical Union approves the proposal, it will change not just that old saying but textbooks and toys and all the other things that rely on nine planets.

NPR: A Down-to-Earth View of the Planet Debate

For decades we've been told nine planets.

NPR: A Down-to-Earth View of the Planet Debate

First, its orbit appears to run in the opposite direction from those of the nine known planets.

ECONOMIST: X marks the spot