Pluto is a planet

[CocoCincinnati]

Everybody knows that pluto is a mass relay encased in ice.

 

[HFY]

Everybody knows that pluto is a mass relay encased in ice.

The mass relay is that green ring in the image, isn't it?

Spoiler: Pluto

 

[klopkr]

Even if pluto isn't classified as a planet in game can it have a custom graphic with it's big beautiful heart?

We can all agree Pluto is too cute to look like an asteroid.

 

[pmchem]

Even if pluto isn't classified as a planet in game can it have a custom graphic with it's big beautiful heart?

We can all agree Pluto is too cute to look like an asteroid.

yeah. nice pic.

I mean, it's clearly NOT an asteroid. something in its in-game label should be changed.

 

[BrokenSky]

You know what Sagan would have said about dogmatically refusing to adapt one's understanding in face of new evidence?

Science moves, it adapts it tests and discards that which does not survive the test. That's why it's useful!

You're not doing Sagan's memory any good turning his attempt to explain science into an article of dogma.

I mean, technically Pluto isn't a planet, 'cause it isn't visible in the sky from Earth with the naked eye. It's clearly just a lump of rock with enough mass to have become spherical under the effects of it's own gravity and to have a moon which has also done that, which puts it in the same category of non-planet celestial bodies as Neptune, Earth and Uranus.

The only real planets are Mercury, Venus, Mars, Jupiter and Saturn.


Or to put it another way, the question of whether Pluto is a planet or not it is only about whether you dogmatically adhere to one arbitrary definition or another. Science hasn't changed to make Pluto 'not a planet' - English has.

 

[Eled the Worm Tamer]

I mean, technically Pluto isn't a planet, 'cause it isn't visible in the sky from Earth with the naked eye. It's clearly just a lump of rock with enough mass to have become spherical under the effects of it's own gravity and to have a moon which has also done that, which puts it in the same category of non-planet celestial bodies as Neptune, Earth and Uranus.

The only real planets are Mercury, Venus, Mars, Jupiter and Saturn.


Or to put it another way, the question of whether Pluto is a planet or not it is only about whether you dogmatically adhere to one arbitrary definition or another. Science hasn't changed to make Pluto 'not a planet' - English has.

Science has changed though, requiring for the astronomical definition of 'planet' that a body not only be marge enough to form something basically spherical (Pluto does this) but also to have cleared its orbit of other bodies down to a thing of a certain scale (Pluto does not do this, not Ceres, Eris, Makemake and the other dwarf planets)

Now whether that is a reasonable criterion is up for debate, and a case can be made that its biased against rocky planets past the mid-system where orbits become increasingly long, but I have never seen anyone who wants Pluto undwarfed take the step of consistency and ask the same applied to its other cousins.

So its clearly not about strong feelings of the criteria being flawed, they just seem to want the solar system as listen and defined now to look exactly like the one they learned as children.

Personally my own preference would be to make every one learn about Ceres, Eris, Makemeke and the others, complicate the ping pong ball orreries of childhood science fairs and show that science is a process not a dogma in word and deed.

( & to anyone voting me down, 'Your boos mean nothing, I've seen what makes you cheer' )

 

[HFY]

I mean, technically Pluto isn't a planet, 'cause it isn't visible in the sky from Earth with the naked eye.

If that's the criteria, then we just need one scientist with glasses to prove that there are no planets.


wait not those glasses

 

[BrokenSky]

Science has changed though, requiring for the astronomical definition of 'planet' that a body not only be marge enough to form something basically spherical (Pluto does this) but also to have cleared its orbit of other bodies down to a thing of a certain scale (Pluto does not do this, not Ceres, Eris, Makemake and the other dwarf planets)

Now whether that is a reasonable criterion is up for debate, and a case can be made that its biased against rocky planets past the mid-system where orbits become increasingly long, but I have never seen anyone who wants Pluto undwarfed take the step of consistency and ask the same applied to its other cousins.

So its clearly not about strong feelings of the criteria being flawed, they just seem to want the solar system as listen and defined now to look exactly like the one they learned as children.

Personally my own preference would be to make every one learn about Ceres, Eris, Makemeke and the others, complicate the ping pong ball orreries of childhood science fairs and show that science is a process not a dogma in word and deed.

( & to anyone voting me down, 'Your boos mean nothing, I've seen what makes you cheer' )

As I said, that's not a change in the science, that's moving the goalposts on what makes a planet. We didn't learn something new about Pluto, we just decided to change the definition to exclude a bunch of planets because we discovered a bunch of new ones all around the same time.

Mostly, I think, stuff like this annoys me because it's basically entirely arbitrary, but people who disagree with the change on equally arbitrary grounds tend to get mocked as though adhering to the one arbitrary standard is somehow "more scientific" than the other (see Rick and Morty cartoon on page 2). It would be just as fair to say "a Planet is an object with enough mass to have moons, but not enough mass to have fusion", which includes Pluto and discludes Mercury and Venus, or to say "a Planet is an object which orbits a star and is massive enough to become spherical under it's own gravity", which includes Pluto as well as Ceres and a host of others, or even say "Planet originally meant 'Wandering Star', so a Planet is an object which is large enough and close enough to be visible from Earth in the sky with the naked eye, but not large enough or close enough to be resolvable as meaningfully larger than a point" (i.e. something which looks like a star from Earth), which discludes Pluto, but also Neptune and Uranus (which is my personal preference for arbitrary definitions because it's both close enough to the original meaning to claim seniority and stupid enough to make a mockery of arbitrary, non-practical definitions).

If you've never heard anyone who wants people to acknowledge that Pluto is a real planet also argue the same thing for Ceres, I doubt you've had a (semi)meaningful conversation about it? - it tends to come up even in non serious conversations like this one. I've never heard anyone explicitly arguing that Pluto was a planet and that Ceres wasn't, for example?


When it comes to Stellaris (and honestly probably also real life), I think I prefer an actually useful definition, which basically tends towards qualities which are related to things like colonization, e.g. "a large enough gravity well to trap liquid water" or "a large enough land area to support a self-sufficient colony". From most practical standpoints, a practical definition which includes Mercury will also include planets like Pluto and Ceres.

 

[drawar]

Terrestrial planet: Mercury, Venus, Earth, Mars
Gas giant : Jupiter, Saturn
Ice giant : Uranus, Neptune
Dwarf Planet : Ceres, Orcus, Pluto (Charon), Haumea, Quaoar, Makemake, Gonggong, Eris, Sedna, +++

Here, no jealousy!

 

[Eled the Worm Tamer]

As I said, that's not a change in the science, that's moving the goalposts on what makes a planet. We didn't learn something new about Pluto, we just decided to change the definition to exclude a bunch of planets because we discovered a bunch of new ones all around the same time.

Mostly, I think, stuff like this annoys me because it's basically entirely arbitrary, but people who disagree with the change on equally arbitrary grounds tend to get mocked as though adhering to the one arbitrary standard is somehow "more scientific" than the other (see Rick and Morty cartoon on page 2). It would be just as fair to say "a Planet is an object with enough mass to have moons, but not enough mass to have fusion", which includes Pluto and discludes Mercury and Venus, or to say "a Planet is an object which orbits a star and is massive enough to become spherical under it's own gravity", which includes Pluto as well as Ceres and a host of others, or even say "Planet originally meant 'Wandering Star', so a Planet is an object which is large enough and close enough to be visible from Earth in the sky with the naked eye, but not large enough or close enough to be resolvable as meaningfully larger than a point" (i.e. something which looks like a star from Earth), which discludes Pluto, but also Neptune and Uranus (which is my personal preference for arbitrary definitions because it's both close enough to the original meaning to claim seniority and stupid enough to make a mockery of arbitrary, non-practical definitions).

If you've never heard anyone who wants people to acknowledge that Pluto is a real planet also argue the same thing for Ceres, I doubt you've had a (semi)meaningful conversation about it? - it tends to come up even in non serious conversations like this one. I've never heard anyone explicitly arguing that Pluto was a planet and that Ceres wasn't, for example?


When it comes to Stellaris (and honestly probably also real life), I think I prefer an actually useful definition, which basically tends towards qualities which are related to things like colonization, e.g. "a large enough gravity well to trap liquid water" or "a large enough land area to support a self-sufficient colony". From most practical standpoints, a practical definition which includes Mercury will also include planets like Pluto and Ceres.

Yeah, on reflection and with my background being I admit in geology not astronomy, I don't think 'ability to clear one's own orbit of significant bodies' is arbitrary.

If we are classifying astronomically relevant chunks of matter, the classifications need to say something useful. Based on the accretion disk theory of planetary formation (and its implications re a given body's elementary make up) then the orbital clearing or not is actually meaningful. Its also less anthropocentric than trying to treat old Terra as a baseline.

 

[KNakamura]

As I said, that's not a change in the science, that's moving the goalposts on what makes a planet. We didn't learn something new about Pluto, we just decided to change the definition to exclude a bunch of planets because we discovered a bunch of new ones all around the same time.

Mostly, I think, stuff like this annoys me because it's basically entirely arbitrary, but people who disagree with the change on equally arbitrary grounds tend to get mocked as though adhering to the one arbitrary standard is somehow "more scientific" than the other (see Rick and Morty cartoon on page 2). It would be just as fair to say "a Planet is an object with enough mass to have moons, but not enough mass to have fusion", which includes Pluto and discludes Mercury and Venus, or to say "a Planet is an object which orbits a star and is massive enough to become spherical under it's own gravity", which includes Pluto as well as Ceres and a host of others, or even say "Planet originally meant 'Wandering Star', so a Planet is an object which is large enough and close enough to be visible from Earth in the sky with the naked eye, but not large enough or close enough to be resolvable as meaningfully larger than a point" (i.e. something which looks like a star from Earth), which discludes Pluto, but also Neptune and Uranus (which is my personal preference for arbitrary definitions because it's both close enough to the original meaning to claim seniority and stupid enough to make a mockery of arbitrary, non-practical definitions).

If you've never heard anyone who wants people to acknowledge that Pluto is a real planet also argue the same thing for Ceres, I doubt you've had a (semi)meaningful conversation about it? - it tends to come up even in non serious conversations like this one. I've never heard anyone explicitly arguing that Pluto was a planet and that Ceres wasn't, for example?


When it comes to Stellaris (and honestly probably also real life), I think I prefer an actually useful definition, which basically tends towards qualities which are related to things like colonization, e.g. "a large enough gravity well to trap liquid water" or "a large enough land area to support a self-sufficient colony". From most practical standpoints, a practical definition which includes Mercury will also include planets like Pluto and Ceres.

All definitions are arbitrary, the point is does the definition convey meaning? And in this case, Pluto being a dwarf planet does.

 

[Idle America]

As others have said, it's no longer classified as a planet. The only reason it was in the first place is because the definition of a planet was too broad. If anything, it shouldn't appear at all if the rest of the dwarf planets don't.

Having said that, I wouldn't mind seeing all the other dwarf planets included. Especially if Pluto had Charon, and was more rounded instead of the wonky shape it's in now.

 

[BrokenSky]

Yeah, on reflection and with my background being I admit in geology not astronomy, I don't think 'ability to clear one's own orbit of significant bodies' is arbitrary.

If we are classifying astronomically relevant chunks of matter, the classifications need to say something useful. Based on the accretion disk theory of planetary formation (and its implications re a given body's elementary make up) then the orbital clearing or not is actually meaningful. Its also less anthropocentric than trying to treat old Terra as a baseline.

See there are three problems with that definition; the first is Jupiter - as I understand it, the reason that there is an asteroid belt between Mars and Jupiter is because of the interference of Jupiter's gravity in disrupting planetary formation. The lack of any body in this region which has cleared out all debris is not due to a lack of capacity of any body within the ring, but rather due to outside interference.

The second problem is that most planets haven't actually done this. I recall not too long ago when they claimed that they'd discovered a second "moon" for Earth, before later redacting that claim on the grounds that there were actually a ton of such bodies. The presence of these imply that Earth has not actually cleared out it's own orbit. Given that objects in this region would be easier to find for earth than other planets, it's not unlikely that every planet has debris in it's orbital region. If nothing else, we can say for sure that all the gas giants do (they all have both rings and moons) as well as Earth, Mars, Pluto and other small planets like Ceres.

The third problem is the historically popular sci-fi trope "what if there were another planet in Earth's orbit on the opposite side of the Sun". With this definition, the status of Earth as a planet would be changed by the presence of such a planet despite Earth itself being identical.

Ultimately what all of these show is the same point I've been making from the get go - that if Pluto were identical in every way, but there were no other debris, it would be considered a planet. Since our own Pluto is identical in every way to this hypothetical 'Planet-Pluto', they should either both or neither be planets.
Or to put it another way, if we moved Venus into the same orbital radius as earth, on the opposite side of the sun, in order to more easily terraform it into another earth (since they already have similar mass), it shouldn't make Earth and Venus both suddenly stop being planets. Whether something is a planet or not should be a description of the object itself, not of the system it exists in (so a 'Star' which never reaches enough mass to begin fusion is a rogue gas giant orbiting the galactic core directly).
I really don't feel like this kind of classification is particularly useful even from a purely academic perspective, let alone a more directly practical one. (A more useful set of practical definitions would be based on things like "What the considerations to mining, colonizing or terraforming Pluto? - Identical to that of a small, cold, rocky planet").

This issue also directly leads to the weirdness in Stellaris commented on by the OP, where Pluto is shown as a misshapen lump of rock, despite being a smooth sphere IRL, because they don't want to show it as a 'planet'.

 

[KNakamura]

See there are three problems with that definition; the first is Jupiter - as I understand it, the reason that there is an asteroid belt between Mars and Jupiter is because of the interference of Jupiter's gravity in disrupting planetary formation. The lack of any body in this region which has cleared out all debris is not due to a lack of capacity of any body within the ring, but rather due to outside interference.

That isn't a problem, becaue I can't even tell how you'd argue against the definition.

The second problem is that most planets haven't actually done this. I recall not too long ago when they claimed that they'd discovered a second "moon" for Earth, before later redacting that claim on the grounds that there were actually a ton of such bodies. The presence of these imply that Earth has not actually cleared out it's own orbit. Given that objects in this region would be easier to find for earth than other planets, it's not unlikely that every planet has debris in it's orbital region. If nothing else, we can say for sure that all the gas giants do (they all have both rings and moons) as well as Earth, Mars, Pluto and other small planets like Ceres.

Second problem isn't a problem:
"Clearing the neighbourhood" around a celestial body's orbit describes the body becoming gravitationally dominant such that there are no other bodies of comparable size other than its natural satellites or those otherwise under its gravitational influence.

Didn't take long to find. It's a well known definition of what it means, and it's why Pluto doesn't qualify.

 

[Ashantai]

Alright, this has long left the rails.