“We don’t have a dictionary definition yet that includes all the contingencies.”
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The definition of “planet” was determined in 2006 by idiots at the International Astronomical Union (IAU). They said that (in the Solar System) a planet is a celestial body that:
1.is in orbit around the Sun,
2.has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and
3.has “cleared the neighbourhood” around its orbit.
#3 creates a HUGE problem because Pluto crosses the orbit of Neptune and is actually closer to the Sun than Neptune for 20 years at a time (out of 165 year long orbit). So the problem with rule #3 is that Neptune hasn’t “cleared its own neighborhood” so it shouldn’t be a planet either!
:’) Thanks, I needed that!
When does Neptune collide with the rock formerly known as Pluto?