Pluto the Planet :D

[Albert VDS]

It still might be a planet. Not because of this mission, but because the scientists here on Earth cannot seem to make up their mind about things. We try to design categories for something we only barely know and that is bound to lead to adjustments down the line.

Actually the IAU clearly made their mind up on how to categorize Pluto and all the other dwarf planets.

It's a spherical object in the Kuiper Belt, smaller than our Moon, it's 50-70% rock and 30-50% ices, has an inclined orbit our the Sun, hasn't cleared it's neighborhood and has a surface area almost equal to Russia.

What do we need to know more about Pluto to change it classification back to planet(or anything else)?

[John FX]

Don`t care what the definition is and that it would apply to many kuiper belt objects. For me, anything that was a planet when we walked on the moon is what the planets are.

Pluto will always be a planet to me.

The word planet is from the greek for `wandering star` which is what it is. We look at it, it looks like a star from here and it wanders.

Still, the science from going to the first kuiper belt object must be good. Bet the scientists who are working on it must have aching faces from smiling so much.

[LittleBlueGaming]

I don't believe on holding onto old ideas just because they are old. Our understanding of the universe evolves, and classifications evolve too.

Or maybe we shouldn't classify the sun as a star, because historical value

[vger]

It still boggles my mind that we even know about it. Finding Pluto was blind luck.

[peadar1987]

Don`t care what the definition is and that it would apply to many kuiper belt objects. For me, anything that was a planet when we walked on the moon is what the planets are.

Pluto will always be a planet to me.

The word planet is from the greek for `wandering star` which is what it is. We look at it, it looks like a star from here and it wanders.

Still, the science from going to the first kuiper belt object must be good. Bet the scientists who are working on it must have aching faces from smiling so much.

Maybe they'll be able to unlock the NERVA now.

[Crampman]

I'm sorry, but I don't understand this romantic thing with Pluto. I mean, it's just a small icy, rocky ball, very far away...

I'm still exited with all the very cool pictures we get those days, and I'm eager to see the next ones, but it's still an object among many others, yet to explore. Let's launch tons of probes to all the dwarves planets !

[vger]

I'm sorry, but I don't understand this romantic thing with Pluto.

It's very romantic. It has great cuddle weather.

[Dooz]

https://en.wikipedia.org/wiki/Clearing_the_neighbourhood

By the IAU definition of planet. Neptune is not a planet.

It should be largest object in the neighborhood is what defines a planet. now pluto dominates kuiper belt in terms of size, i think it should be a planet or a new classification between planet and dwarf planet.

[Kibble]

Pluto is a minor planet! But not one of the 8 Planets that take up more than 99% of the non-Sun mass of the Solar System.

https://en.wikipedia.org/wiki/Clearing_the_neighbourhood

By the IAU definition of planet. Neptune is not a planet.

That criterion only refers to a planet's capacity to clear its neighborhood. Pluto is in a resonance.

Edited July 14, 2015 by Kibble

[LittleBlueGaming]

https://en.wikipedia.org/wiki/Clearing_the_neighbourhood

By the IAU definition of planet. Neptune is not a planet.

It should be largest object in the neighborhood is what defines a planet. now pluto dominates kuiper belt in terms of size, i think it should be a planet or a new classification between planet and dwarf planet.

By their definition, it is. 'Clearing the neighborhood' in this sense is a technical term.

...meaning it has become gravitationally dominant, and there are no other bodies of comparable size other than its own satellites or those otherwise under its gravitational influence.

[Superfluous J]

Why would you want to downgrade Pluto from the first discovered [edit: I actually got this wrong. Ceres was discovered far before Pluto], first visited, most prominent Dwarf Planet out there to a tiny, last visited tag-along planet that couldn't hold its own against a lot of moons?

Asking this question is like asking, "Now that we know far more about the majestic Elephant, will you kindly reconsider my ages-old petition to consider them as proper Lemurs?"

- - - Updated - - -

The word planet is from the greek for `wandering star` which is what it is. We look at it, it looks like a star from here and it wanders.

So Earth isn't a planet? And the Sun is? And I assume the Moon is as well.

Edited July 14, 2015 by 5thHorseman

[YNM]

https://en.wikipedia.org/wiki/Clearing_the_neighbourhood

By the IAU definition of planet. Neptune is not a planet.

It should be largest object in the neighborhood is what defines a planet. now pluto dominates kuiper belt in terms of size, i think it should be a planet or a new classification between planet and dwarf planet.

Earth isn't a planet because of this, and many similars. Jupiter have packs of them, even.

Well, lets leave it to those "diehard astronomers". Us amateurs, lets gaze on the new data, point out craters, ridges, canyons, mountains, and ducks, shall we ?

[Dooz]

https://en.wikipedia.org/wiki/Clearing_the_neighbourhood

By the IAU definition of planet. Neptune is not a planet.

It should be largest object in the neighborhood is what defines a planet. now pluto dominates kuiper belt in terms of size, i think it should be a planet or a new classification between planet and dwarf planet.

Just noticed a problem with this.

if we started calling pluto a planet we would also have to call

Ceres a planet largest body in the asteroid belt

eris a planet Largest body in the scattered disc

Yep I think we need a definition between Dwarf planet and planet

[YoetoJoe]

If we take has "cleared the neighborhood" around its orbit as the reason to demote Pluto then we also have to demote every other planet because of comets/asteroids that go in and out of the planets orbit, any Trojans the planet has, and any moons because you could say that they are "in the neighborhood". After a quick google search it appears that Mercury would be the only planet still meeting this requirement.

[Robotengineer]

It's not romantic. It's nationalism. The only "planet" ever discovered by someone from USA and now it's not anymore. That causes enormous butthurtness.

It's old Europe still trying to take away our independence! Pluto shouldn't even be Pluto, cause that's Greek! And Greeks are Europeans! It should be Georgium Washingtonus! Or Planet Freedom! /'Mericanism

Even if there was an Earth size planet way out in the Kuiper Belt it still wouldn't be a planet IMO. Pluto should be content with being a Dwarf Planet.

Edited July 14, 2015 by Robotengineer

[peadar1987]

If we take has "cleared the neighborhood" around its orbit as the reason to demote Pluto then we also have to demote every other planet because of comets/asteroids that go in and out of the planets orbit, any Trojans the planet has, and any moons because you could say that they are "in the neighborhood". After a quick google search it appears that Mercury would be the only planet still meeting this requirement.

"Cleared the neighbourhood" doesn't means "Nothing sharing the orbit", it means that everything else in the orbit is dominated by gravitational interactions with that body. So Neptune has cleared its orbit, because the only things sharing it are Trojan asteroids and Plutinoids locked into a 3:2 orbital resonance (and minor Neptune-crossers which haven't been fully cleared). The same with Earth, everything earth-crossing is either locked in orbital resonance with earth (like Cruithne), or it is slowly being perturbed either towards an orbital resonance or ejection from earth's orbit.

There is a mathematical parameter used to determine how dominant a planetary body is over its orbit, and how likely it is to clear its neighbourhood over astronomical timescales. It is called the Stern-Levison Parameter, and is anything but arbitrary. The major planets have Stern-Levison parameters from 942 (Mercury) to 1.3E9 (Jupiter). The most gravitationally dominant dwarf planet over its orbit is Pluto, with a Stern-Levison parameter of 2.95E-3. So Jupiter is 7 orders of magnitude more dominant than Mercury, and Mercury is 5 orders of magnitude more dominant than Pluto. Pluto, Ceres, Eris, Haumea and Makemake all have S-L parameters of roughly the same order of magnitude, so if you let one in you have to let them all in. Not that I'm against that, but the IAU defined a very clear cut-off point of a Stern-Levison parameter of 100 for full planetary status. It's not a subjective "yeah that orbit is probably clear enough" sort of a thing.

Edited July 14, 2015 by peadar1987

[Vanamonde]

A number of posts had been removed from this thread for attacking each other's nationalities, being off-topic, and so on. And please, guys: avoid the jokey images, okay?

[AngelLestat]

Pluto is boring.. is small, it does not have any significant atmosphere, there is not energy there, is geologically death, it has not future use for humanity.. is just like any other rock out there.

We should destroy it... for not particular reason, or crash it against neptune, to see what happens.

Edited July 14, 2015 by AngelLestat

[Camacha]

Dear Jeb, it seems we are going to repeat the whole discussion almost to the letter. These are all the same points and arguments that have been treated ad nauseam. Could we at least all read the old discussions, so we do not have do it all over again?

Actually the IAU clearly made their mind up on how to categorize Pluto and all the other dwarf planets.

For now, yes. It is bound to change, either because others disagree (like NASA seems to be at least partly doing), or because new science changes our view of what's out there.

You can bet definitions are going to be upturned as soon as we ever get a good look at any system beyond our own.

[Bill Phil]

If I want to call Pluto a planet, then I can.

If enough people decide to keep calling it a planet, then the only thing it can be considered is a planet.

[LittleBlueGaming]

For now, yes. It is bound to change, either because others disagree (like NASA seems to be at least partly doing), or because new science changes our view of what's out there.

You can bet definitions are going to be upturned as soon as we ever get a good look at any system beyond our own.

That's the best thing about science, anything can be overturned. It goes against the very essence of science to hold on to an old idea just because it's the one you're familiar with.

If we just, today, discovered everything we know about in the solar system, how would we classify it? Pluto makes sense as a planet when you're shown a simple diagram in school, but not so much when you're looking at a more realistic representation of the solar system.

[Albert VDS]

For now, yes. It is bound to change, either because others disagree (like NASA seems to be at least partly doing), or because new science changes our view of what's out there.

You can bet definitions are going to be upturned as soon as we ever get a good look at any system beyond our own.

Other systems won't change anything about Pluto, it will only enforce that it's a dwarf planet.

The simple reason is that dwarf planets will never have a significant gravitational interaction.

There might be solar systems which are filled with dwarf planets and it wouldn't change that view.

Thinking it will change is like thinking spiders will be categorized as insects in the future.

There are clear and simple characteristics why they are arachnids and that wont change if any other insect or spider species are found.

[Stargate525]

Other systems won't change anything about Pluto, it will only enforce that it's a dwarf planet.

The simple reason is that dwarf planets will never have a significant gravitational interaction.

There might be solar systems which are filled with dwarf planets and it wouldn't change that view.

Thinking it will change is like thinking spiders will be categorized as insects in the future.

There are clear and simple characteristics why they are arachnids and that wont change if any other insect or spider species are found.

Except the biggest thing is that 'it hasn't cleared its orbit.' According to certain definitions, EARTH hasn't cleared its orbit.

[Superfluous J]

Except the biggest thing is that 'it hasn't cleared its orbit.' According to certain definitions, EARTH hasn't cleared its orbit.

According to certain definitions, Jupiter hasn't cleared it's orbit.

According to the official definition used by the official requirements for a planet to be a planet, they both have. And Pluto has not.

Note, I'm not saying I agree. Personally I think Ceres should be a planet. And so should the Moon, Io, Europa, Ganymede, Callisto, Titan, and Triton. And maybe a few more satellites. But that's just me.

[Albert VDS]

Except the biggest thing is that 'it hasn't cleared its orbit.' According to certain definitions, EARTH hasn't cleared its orbit.

Is Earth not gravitationally dominant in it's orbit?