Comments by "Sebastian Nolte" (@sebastiannolte1201) on "Astrum"
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" Orbits a star, round surface, it has moons, and it even has an atmosphere."
So that are your definition for a planet? Well, the International Astronomical Union has another definition. By that a planet has to fullfill three things:
1. Orbits the sun
2. is more or less a sphere
3. Is the main object in its surrounding, so has cleared its orbit
Pluto fulfills only 1 and 2, but not 3.
" It's even called a "dwarf planet." "
Yes, that is the name for objects that fulfills 1 and 2 of the things above. BTW that also means that in the same moment, when Pluto was downgraded from "planet" ot "dwarf planet", Ceres was upgraded from "asteroid" to "dwarf planet".
"The size does not matter"
Correct, as you see above, the size is not relevant for the question if an object is categorized as "planet" or "dwarf planet".
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9th? It is the 13th: Mercury, Venus, Earth, Mars, Ceres, Juno, Vesta, Astraea, Jupiter, Saturn, Uranus, Neptun, Pluto.
The people who claimed, that Ceres, Juno, Vesta and Astraea are no planets anymore back in 1847 can rot in Hades!
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@personalcoach2131
I think you have a wrong image of the Kupier belt (to be honest I already thought that after reading your initial question, so my answer was a bit provoking, sorry for that). Let's stay with the forest comparison. If the Kuiper Belt was a forest and Pluto was a tree in it, then you would only have a picture of that single tree and around it there would be nothing. Because the next tree in that forest is miles away. Probably nobody even would call it a "forest".
Space mainly constists of nothing, a complete void. Here a scale model: If the sun has a diameter of one meter, then Mercury is 41 m away and would only have a size of 3.5 mm. Earth would 107 m away, Jupiter 556 m, Pluto 4219 m and the next star Proxima Centauri would be 28800 km (!) away. So if you hear terms like "asteroid belt", "Kupier belt" and "Oort cloud" you better should take them metaphorically. Because they are regions with a higher density of objects - but only in comparison to the rest of the solar system. They still consist of mainly nothing and the distance between the objects in that "belts" is huge.
Actually New Horizons flew further after passing Pluto and went to (486958) Arrokoth, an object in the Kuiper Belt. It is the furthest object that was ever visited by a probe. But New Horizon needed 3.5 years from Pluto to Arrokoth although it flies with the incredible speed of about 15 kilomters per second! On its way it also made pictures of other objects in the Kuiper Belt, but they were millions of kilometers away.
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"Pluto has always been a planet and will always be a planet."
Pluto has always been what it is. "Planet" is a category made by humans, so they can decide what a planet is or not. The name comes from ancient greece and means something like "wanderer". Because people noticed that there are stars on the sky who are not fixed but move independet from each other, so they call them "planets". At a time, when people didn't know that earth itself was a planet.
"The ancients knew way before today’s scientists & astronomers wanna be stupid."
The ancients only knew the planets, that can be seen with your naked eye: Mercury, Venus, Mars, Jupiter, Saturn. So five planets.
When heliocentrism was discovered we found out that earth is a planet, too, so we had six planets.
In 1781 Uranus was discovered, so we had seven planets.
In the middle of the 19th century we discovered small planets between Mars and Jupiter: Ceres, Pallas, Juno, Vesta, Astrea. So we had twelve planets
In 1846 Neptune was discovered, so we had thirteen planets.
But then we found more and more small objects between Mars and Jupiter, and scientist back then thought: We cannot call them all "planets". Let's make a new category "asteroid". So Ceres, Pallas, Juno, Vesta and Astrea were downgraded from "planet" to "asteroid". So we had only eight planets.
In 1930 Pluto was discovered. And first we thought it was bigger than it actually is. It was catogerized as planet. So we had nine planets. But especially when we found out that it was smaller, people started to discuss if it should be called a planet.
In 2005 we found Eris beyond Pluto, so a tenth Planet? Shorl after that Makemake was discovered. And we had the same situation as in the 1850s, so more and more objects in a belt were discovered and the question was: Should they all be called planets? And they decided: No, let's make a new definition for "planet". And Pluto didn't fullfill that new definition anymore, so it was downgraded from "planet" to "dwarf planet". BTW; with that new definitions, Ceres was upgraded from "asteroid" to "dwarf planet".
We can discuss about the nw definition, I don't want to say that it is good (actually I don't care). But your "argument" just doesn't make any sense and shows that you have no idea about these topics. There are thousands of objects orbiting around the sun. And only from 1930 to 2006 we called nine of them "planets". And you really come up with numerolgy, say that "9" is special number and come up with the ancients? It is really ironic that you critizse "stupid modern scientists cannot just say, that we only have eight planets now", while it also were "stupid modern scientists" who decided that we had nine plantes before.
What is your definition for "planet"?
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@SophiesDriver
" I made my position abundantly clear. "
I haven't heard a definition from you. And I don't want to argue that Pluto is not a planet, and I don't want to say that the planet definition of 2006 is good.. But many people just seem to be nostalgic and just claim (quite narcissistic, actually), that for all time the nine planets, that they lived with during their life, have to be stay the same. But I cannot think of a good and scientific definition where exactly Mercury, Venus, Earth, Mars, Jupiter, Saturn, Neptune, Pluto (not more, not less) are planets.
"Pluto's reclassification by administrators was not science, it is a funding grab"
Were there mainly administrators at the IAU during the 2006 voting, or why are you talking about "administrators"? And I wonder if you think that the reclassification of Ceres, Pallas, Juno, Vesta and Astrea in 1851 was scientific? And the next reclassification of Ceres in 2006?
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@Haraka111
"A dwarf planet is still a planet that's my point.."
I heard that often, it is interesting. Maybe it has to do with the language, but I am German, so here the category is called "Zwergplanet". And we have many names for example in the animal world where such a connected word doesn't mean, that it is an actual part of the one word. And there are some in English, too: A "guinea pig" is not a pig. A "sea leopard" (well, maybe you know it as "leopard seal", but in german it is just "Seeleopard") is not a leopard. So to me, a "dwarf planet" can be its own category. It doesn't have to be a subcategory of "planet".
"I would say a space object with a regular orbit around a star."
That is the case for thousands of objects :-)
"usually circular"
Well, Okay, then dwarf planets would also count as planets to you. That is fine. The only difference between "planet" and "dwarf planet" is, that the dwarf planet has not clean its orbit from other objects.
"my point is Pluto is a dwarf planet or little planet.. that means it's still a planet.."
As explained above, it is interesting that it seems to be a language thing. As we write things together (the German language is famous for that, so you can create very long words, that actually exist), it is even easier to take "dwarf planet" as its own thing, because we call it "Zwergplanet" and not "Zwerg Planet". :-)
Oh, and don't get me wrong, I don't want to say that these definitions for planet and dwarf planet, that the IAU made in 2006 are good or that I agree. They are also contoversial among scientists.
One reason for the definition was, that more and more objects in the Kuiper belt was found, and the question was: Should they all count as planets? So it was the same situation as in 1850, when more and more objects were found in the asteroid belt. So they said: If not all new found round objects in the Kuiper Belt should count as planets, there hass to be a distinctions. And Pluto has more in common with the Kuiper Belt objects than with the planets. On the other hand: It would also make sense to make a distinction between the small inner solid planets (Mercury, Venus, Earth, Mars) and the big gas planets (Jupiter, Saturn, uranus, Neptune), because they are very different. But we still put them in the same category.
However, we don't need a big discussion here :-) I don't really care, at the end it is just about names and artificial categories. It doesn't change anything about the objects.
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