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Scientists didn’t become pickier - they just later found that Pluto was in a belt of thousands of massive object (called the Kuiper belt), like the asteroid belt but much bigger.
When Ceres was discovered in 1801, it was thought to be a comet, later a planet, but after discovering it was one of many asteroids in the asteroid belt (which it wasn’t big enough to clear), they realized it wasn’t a planet.
When Pluto was first discovered in 1930, it was in a similar situation as Ceres and thought of as a planet, but when other Kuiper belt objects started to be discovered by 1992, they realized Pluto also wasn’t a planet.
givesomefucks@lemmy.world 4 weeks ago
Do some leople think Pluto actually got smaller and thats why it’s not a planet?!
dual_sport_dork@lemmy.world 4 weeks ago
I wouldn’t put it past an awful lot of people given the stupidity I see on a daily basis.
Pluto is a strange relic that basically got considered a planet only due to the time and method by which it was observed. But it turns out that there are a lot of things in the solar system that are about the size of Pluto or even larger which would require us to either declare there are dozens and dozens of planets or, the slightly more sane avenue, come up with a slightly more specific definition of what a planet actually is which by necessity excludes Pluto.
All the hype about is basically just down to people refusing to change what they learned in elementary school. But the thing about science is that it changes and is refined over time as we gain understanding of the universe and how things work. This is what makes science science. Anything less is simply dogma.
Lumidaub@feddit.org 4 weeks ago
And it’s baffling because how does that even affect anyone in any way unless they work in astronomy? People don’t know and don’t care about the difference between solar system, galaxy and universe, but Pluto being recategorised is STILL causing them intolerable agony?
leftzero@lemmynsfw.com 4 weeks ago
Calculation error due to Einstein not being available (in Lowell’s case, at least; Tombaugh should’ve known better) and margins of error in the measured masses of the planets at the time (the Voyagers took care of that bit), if I’m not mistaken.
Nollij@sopuli.xyz 4 weeks ago
The explanation I heard back then was that Pluto wouldn’t qualify as a planet, EXCEPT that it has a moon. I’m not sure why that exception would apply, but it seems it’s no longer good enough.
iasmina2007@lemmy.world 4 weeks ago
wewbull@feddit.uk 4 weeks ago
That’s correct by definition, but the reason the definition was changed to exclude pluto was because our knowledge changed.
We found more Pluto-like objects and it became clear they weren’t the same thing as the other 8 planets. They needed their own classification. So we created one (Dwarf Planets) and put Pluto in it along with its brethren.
sxan@midwest.social 4 weeks ago
And also because if we included Pluto, we’d have to include another half dozen Pluto-sized dwarves we’ve discovered since.
But, yeah, my understanding is that it’s really about dominance. Pluto is too submissive. Not alpha enough, if you will.