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There is massive irony in the tall mountains of Pluto. Remember how Galileo used a telescope to look at the Moon and he discovered it has mountains?... /1
2/ Before then, the belief was that the planets are heavenly & obey a different physics than the Earth. Galileo argued the Moon isn't a perfect, heavenly sphere because the mountains prove it follows the same physics as the Earth. Literally "geo-physics" (geo- means "Earth").
3/ This was why he argued (vociferously, making enemies) for a new meaning of the word "planet", saying they aren't planets because of how they move in the sky, but by what they ARE. Earth became the prototype of planethood by comparing with mountains on the Moon.
4/ Galileo (and all who followed) started calling the Earth, the Moon, the moons of Jupiter, the other classical planets, etc., all "planets", believing they all had mountains (even people!) on them. It was disappointing to slowly learn how much UN-like the Earth they are!
5/ So there is grand irony in Pluto having active mountain building with gigantic mountains. It has complex geophysics arguably more like the complexity of Earth than any other solid planet. This makes it the most planet-like of all the planets based on Galileo's definition.
6/ And yet while @NewHorizons2015 was ON THE WAY to see those mountains, repeating what Galileo did with a telescope 400 years before, ON THE WAY, a scientific assembly claimed it had /authority/ to undo the geophysical foundation of modern planetary science,...
7/ ...embracing a dynamical definition that was deaigned to make ir juat a small number of special, god-like planets based on dynamics instead of geophysics.
8/ ...i.e., they were embracing cultural expectations. People involved in the vote were actually saying culture should be a factor! So every time I see the mountains on Pluto, this is what I see: Galileo's geophysical hallmark of planethood and a big gigantic irony 😅
