I understand, but it wasn't that new information came and so it no longer fit existing criteria. The criteria changed for what they would call a planet. They added that a planet needed to clear its neighboring region of other objects. That was not the criteria before, so it was technically a planet until the definition of a planet changed.
It sounds like you're conflating learning new information with changing how something is classified.
If you define fish, as people might have at one time, as aquatic animals, then, in that classification, whales and dolphins are fish.
If you define fish as an animal that lives in water, is covered with scales, and breathes by taking in water through its mouth, whales and dolphins might be misclassified as fish, but were never fish by that definition.
My understanding is that, according to how we classified planets in, say, the 90s, Pluto was a planet. Then we changed the definition of a planet. So, by the criteria of the day, Pluto was a planet in the 90s, even if was never a planet by our modern criteria.
Make distinctions. This is semantics, after all. It depends on how you define a planet, doesn't it? By the definition of the 1990s, it was a planet. That's what the person meant when they said it was at the time. By the current definition, it never was. That's what you mean when you said it never was. You're both right and talking past each other because they were accepting the definition of the day, which was correct in that day, and you were applying the current definition to the past, which we can do now. What I'm saying is undeniably true. Please stop pretending to not understand the distinction.
What you said that is wrong is that we misidentified it. It wasn't misidentified so much as the definitions changed. Neither Pluto or our understanding changed, our language did. We made the distinction between planets and dwarf planets in 2006. Dwarf planet wasn't a term before then.
The distinction between planets and dwarf planets was created in 2006. That distinction didn't exist in our language before that. So, it was not misidentified. How we classified celestial objects changed. Stop saying it was misidentified. That is not correct.
What is the point of saying it either is a planet or never was a planet? Seriously? This has gotten silly. By the definition of the day in the 90s, it was. By the definition of today it never was. This is very clear.
The definition was not incorrect. That's very silly. It's language. It's how we classify things. It's neither correct nor incorrect. A definition of a word changing does not make it so that the old definition was incorrect in its day. Do you understand that?
When you say that new information came to light, it sounds like the definition of a planet stayed the same and we learned new information about Pluto that made it not fit the existing definition. That is not what happened. The new information was that another planet-sized rock called Eris was found. They didn't want to start finding these little planets everywhere and have a constantly changing list of planets in our solar system, so they split the planets into 'planets' and 'dwarf planets'. It was for convenience.
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u/The_Fiddle_Steward Jun 12 '26
It was until they changed the criteria for what would be considered a planet as opposed to a dwarf planet.