Astronomy and Space Peeps

[Shatter He/Him]

20 hours ago, KaladinsSenseOfHumourSpren said:

Yup, this argument annoys me greatly.

Now, I'd like to build on what I said in the aliens thread: I think the planet definition should change, though not to include Pluto

I think it should be:

1. A certain mass threshold is cleared (something around 10^23 kg)
2. It orbits a star

This way, there can be no ambiguity on whether something has reached hydrostatic equilibrium, and what exactly counts as a 'nearly round' shape

There can also be no debate around whether a planet's orbit is cleared; all planets except Mercury have Trojan asteroids in their orbits.

And as a final perk, exoplanets actually count with this one  

I believe you misunderstand the IAU definition. Orbit clearing does not mean the planet has to eject every single asteroid. It means the planet exerts gravitational influence on the asteroids in its orbit, moving them into the Lagrange points where they can maintain 1:1 resonance with the planet. Also, your mass cutoff is relatively arbitrary. Planet-ness is a continuum from dust to rubble to asteroid to dwarf planet to planet. If you create a mass line, you will make edge cases. This definition would no longer classify objects by structure, formation, and dynamics, but would classify them by two thresholds chosen for convenience. This is extremely weak as a scientific definition. Also, exoplanets already count with the current IAU definition. They're just called exoplanets because they aren't in the Sol System. You can check my full explanation in the ALIENS!!! topic thingamajig. (AKA I can't find it and am too lazy to)

All in all, Pluto is not a planet. It is a dwarf planet which is the precursor to being a planet.

Just don't argue with the IAU laws. They do know what they are doing.

19 hours ago, CoderDrag0n8 said:

Than what if we call them super planets?

There is currently no official definition for a super planet.

...why? We don't need this definition.

2 hours ago, Pathfinder said:

I mean sure? I don’t really care about Star Wars enough to interpret his intent versus what he said. Just for however long, the concept was misunderstood. I just thought how they went about calculating the distances to stars once upon a time very interesting because you can literally emulate it with your own eyes and a thumb. Retcons can retcon lol. 

yeah. it's a theory (that i subscribe to)

 

ALSO EVERYONE. Exoplanets are indeed planets. I dunno what makes y'all think the IAU said they aren't. They orbit stars. 

[KaladinsSenseOfHumourSpren He/Him]

3 hours ago, Shatter said:

I believe you misunderstand the IAU definition. Orbit clearing does not mean the planet has to eject every single asteroid. It means the planet exerts gravitational influence on the asteroids in its orbit, moving them into the Lagrange points where they can maintain 1:1 resonance with the planet. Also, your mass cutoff is relatively arbitrary. Planet-ness is a continuum from dust to rubble to asteroid to dwarf planet to planet. If you create a mass line, you will make edge cases. This definition would no longer classify objects by structure, formation, and dynamics, but would classify them by two thresholds chosen for convenience. This is extremely weak as a scientific definition.

Well, there are also objects like NEOs not in Lagrange points that cross our orbit, and similar objects for other planets. 

All I'm saying is, a 'cleared orbit' is quite ambiguous. 

Also I forgot some extra criteria:

3) The celestial body is not capable of nuclear fusion on a large scale

4) It has a density less than [minimum white dwarf density]

Nothing discovered so far fits these criteria and isn't considered a planet, and so they work.

3 hours ago, Shatter said:

Also, exoplanets already count with the current IAU definition. They're just called exoplanets because they aren't in the Sol System. You can check my full explanation in the ALIENS!!! topic thingamajig. (AKA I can't find it and am too lazy to)

The definition says it must orbit the Sun.

Also I can't find the ALIENS!!! topic, I think it might've been deleted.

3 hours ago, Shatter said:

ALSO EVERYONE. Exoplanets are indeed planets. I dunno what makes y'all think the IAU said they aren't. They orbit stars. 

It says the Sun

[Through the Living Hopper He/Him]

8 minutes ago, KaladinsSenseOfHumourSpren said:

Also I can't find the ALIENS!!! topic, I think it might've been deleted.

I hid it because it got way off topic (thanks Coder)

Edit: also, @CoderDrag0n8, where did you get that image?

[KaladinsSenseOfHumourSpren He/Him]

2 minutes ago, Through the Living Hopper said:

I hid it because it got way off topic (thanks Coder)

Edit: also, @CoderDrag0n8, where did you get that image?

Oh that makes sense.

[CoderDrag0n8 He/They]

4 hours ago, KaladinsSenseOfHumourSpren said:

Wait a minute.

So pluto:

1. Orbits around the sun
2. Is nearly round
3. Hasn't cleared the neighbourhood around it's orbit????

so the only reason pluto is not a full planet

is because of a subjective criteria

yeah that makes sense

4 hours ago, Through the Living Hopper said:

I hid it because it got way off topic (thanks Coder)

Edit: also, @CoderDrag0n8, where did you get that image?

what image?

[Through the Living Hopper He/Him]

9 minutes ago, CoderDrag0n8 said:

Wait a minute.

So pluto:

1. Orbits around the sun
2. Is nearly round
3. Hasn't cleared the neighbourhood around it's orbit????

so the only reason pluto is not a full planet

is because of a subjective criteria

yeah that makes sense

what image?

Planet is a subjective term!

Sorry, pinged the wrong person. @KaladinsSenseOfHumourSpren

[CoderDrag0n8 He/They]

2 minutes ago, Through the Living Hopper said:

Planet is a subjective term!

Sorry, pinged the wrong person. @KaladinsSenseOfHumourSpren

Yes, so then why is it so hard to stretch that subjectivity to include something that in one sense of that term that you stated was subjective is a planet?

[Through the Living Hopper He/Him]

1 minute ago, CoderDrag0n8 said:

Yes, so then why is it so hard to stretch that subjectivity to include something that in one sense of that term that you stated was subjective is a planet?

Because it would clutter the Solar System too much!

[CoderDrag0n8 He/They]

Just now, Through the Living Hopper said:

Because it would clutter the Solar System too much!

Literally how? There were already 9 planets before the change, and that didn't 'clutter' it too much! Also why are we using a subjective reason for a scientific term?

Also why is a scientific term still subjective despite attempts to make it no longer subjective! That just means they did a bad job in defining it if it is still subjective!

[KaladinsSenseOfHumourSpren He/Him]

4 hours ago, CoderDrag0n8 said:

Wait a minute.

So pluto:

1. Orbits around the sun
2. Is nearly round
3. Hasn't cleared the neighbourhood around it's orbit????

so the only reason pluto is not a full planet

is because of a subjective criteria

yeah that makes sense

what image?

3 hours ago, CoderDrag0n8 said:

Literally how? There were already 9 planets before the change, and that didn't 'clutter' it too much! Also why are we using a subjective reason for a scientific term?

Also why is a scientific term still subjective despite attempts to make it no longer subjective! That just means they did a bad job in defining it if it is still subjective!

Exactly why we need a new definition

Pluto isn't a planet, and that should be clear

Coder, Pluto got demoted when Eris was discovered, and Eris was very similar to Pluto in a lot of ways, so if Pluto was considered a planet, and Eris would have to be one too, and then you could argue that every other dwarf planet-sized object should also be a planet, which would make the number of planets 20ish, possibly more

[Shatter He/Him]

 

14 hours ago, KaladinsSenseOfHumourSpren said:

 

The definition says it must orbit the Sun.

i'm pretty sure they include any stars or stellar remnants. that would be sorta dumb

14 hours ago, KaladinsSenseOfHumourSpren said:

Well, there are also objects like NEOs not in Lagrange points that cross our orbit, and similar objects for other planets. 

All I'm saying is, a 'cleared orbit' is quite ambiguous. 

Also I forgot some extra criteria:

3) The celestial body is not capable of nuclear fusion on a large scale

4) It has a density less than [minimum white dwarf density]

sooo are brown dwarfs stars or planets.

Edited May 21 by Shatter

[KaladinsSenseOfHumourSpren He/Him]

11 minutes ago, Shatter said:

i'm pretty sure they include any stars or stellar remnants. that would be sorta dumb

Exactly

IAU should change it

11 minutes ago, Shatter said:

sooo are brown dwarfs stars or planets.

Neither

They don't count in my planet definition because they still do nuclear fusion, just not with hydrogen-1

[Shatter He/Him]

1 minute ago, KaladinsSenseOfHumourSpren said:

Exactly

IAU should change it

Neither

They don't count in my planet definition because they still do nuclear fusion, just not with hydrogen-1

mmm

Maybe they'll get around to it someday soon.

[KaladinsSenseOfHumourSpren He/Him]

Just now, Shatter said:

mmm

Maybe they'll get around to it someday soon.

Yes.

It's been almost two decades...

[Through the Living Hopper He/Him]

9 hours ago, CoderDrag0n8 said:

Literally how? There were already 9 planets before the change, and that didn't 'clutter' it too much! Also why are we using a subjective reason for a scientific term?

Also why is a scientific term still subjective despite attempts to make it no longer subjective! That just means they did a bad job in defining it if it is still subjective!

Any scientific term will be subjective except for fundamental constants. Like I said before, the term is just something we made up, so we made it up not to include a bunch of planets.

I don't understand why people are so mad about this. Pluto didn't stop existing because it's not a planet. You can still look at the beautiful pictures. You can even still believe it has life. It just isn't a planet.

[Shatter He/Him]

4 minutes ago, KaladinsSenseOfHumourSpren said:

Yes.

It's been almost two decades...

You know how bureaucracy works.

This is scientific bureaucracy. It's so much worse.

Just now, Through the Living Hopper said:

Any scientific term will be subjective except for fundamental constants. Like I said before, the term is just something we made up, so we made it up not to include a bunch of planets.

I don't understand why people are so mad about this. Pluto didn't stop existing because it's not a planet. You can still look at the beautiful pictures. You can even still believe it has life. It just isn't a planet.

who the hell believes that dwarf planet has life? mars has more life than pluto

wut?!

I'm tired. see ya'll soon.

Edited May 21 by Shatter

[Through the Living Hopper He/Him]

7 minutes ago, Shatter said:

who the hell believes that dwarf planet has life? mars has more life than pluto

wut?!

I'm tired. see ya'll soon.

The thing that started this whole Pluto argument on the Shard was in my alien discussion thread someone said that life exists on one of our planets, and possibly more, and that Pluto should be a planet.

[CoderDrag0n8 He/They]

17 hours ago, KaladinsSenseOfHumourSpren said:

Exactly why we need a new definition

Pluto isn't a planet, and that should be clear

Coder, Pluto got demoted when Eris was discovered, and Eris was very similar to Pluto in a lot of ways, so if Pluto was considered a planet, and Eris would have to be one too, and then you could argue that every other dwarf planet-sized object should also be a planet, which would make the number of planets 20ish, possibly more

Listen, my point is not that Pluto should be a planet (although it is very cool and think it should be but that's an opinion and only relevant in my hidden Pluto fanfics) my point is that by the current definition, Pluto is a planet, and I don't see how the definition disproves it's planetary status

12 hours ago, Through the Living Hopper said:

Any scientific term will be subjective except for fundamental constants. Like I said before, the term is just something we made up, so we made it up not to include a bunch of planets.

I don't understand why people are so mad about this. Pluto didn't stop existing because it's not a planet. You can still look at the beautiful pictures. You can even still believe it has life. It just isn't a planet.

Yes, but the point of defining something is too change a subjective term we made up into a clearly defined term that we made up, but still has no argument between what does and doesn't count.

I'm just saying, I think the point of defining something is making it less subjective, and so if the definition fails in making it less subjective, than the definition failed!

My argument is: Based on the current definition of a planet, Pluto should be a planet, because of the ambiguity of the definition of planet, so therefore: I agree with Ksauce.

But if we can't change the definition of a planet, THEN WE SHOULD STICK TO IT, AND NOT REMOVE PLANETS 'JUST CAUSE'

If, according to the definition, we should have 50 planets, than we have 50 planets, and someone needs to change the definition, not "oh no, we'll just pretend these things don't count as planets and now we have a nice round number of 8!"

11 hours ago, Through the Living Hopper said:

The thing that started this whole Pluto argument on the Shard was in my alien discussion thread someone said that life exists on one of our planets, and possibly more, and that Pluto should be a planet.

I NEVER THOUGHT PLUTO HAD LIFE

I just like hades

[Through the Living Hopper He/Him]

1 hour ago, CoderDrag0n8 said:

I NEVER THOUGHT PLUTO HAD LIFE

I NEVER SAID YOU DID

1 hour ago, CoderDrag0n8 said:

Yes, but the point of defining something is too change a subjective term we made up into a clearly defined term that we made up, but still has no argument between what does and doesn't count.

I'm just saying, I think the point of defining something is making it less subjective, and so if the definition fails in making it less subjective, than the definition failed!

IT CANNOT BE LESS SUBJECTIVE. IT'S IMPOSSIBLE 

1 hour ago, CoderDrag0n8 said:

But if we can't change the definition of a planet, THEN WE SHOULD STICK TO IT, AND NOT REMOVE PLANETS 'JUST CAUSE'

If, according to the definition, we should have 50 planets, than we have 50 planets, and someone needs to change the definition, not "oh no, we'll just pretend these things don't count as planets and now we have a nice round number of 8!"

THAT'S NOT WHAT HAPPENED! WE DIDN'T JUST REMOVE THE PLANETS, THEY JUST DIDN'T QUALIFY.

But no one's answering my question: why does everyone want Pluto do be a planet so badly?

[CoderDrag0n8 He/They]

3 minutes ago, Through the Living Hopper said:

I NEVER SAID YOU DID

IT CANNOT BE LESS SUBJECTIVE. IT'S IMPOSSIBLE 

THAT'S NOT WHAT HAPPENED! WE DIDN'T JUST REMOVE THE PLANETS, THEY JUST DIDN'T QUALIFY.

But no one's answering my question: why does everyone want Pluto do be a planet so badly?

IT LITERALLY CAN BE! Just define things better! Like, it must have a mass greater than x kilograms or tons! It must orbit a star is actually a pretty dope one!

I DIDN'T MEAN THEY WERE REMOVED USE CONTEXT CLUES! They "didn't qualify"? Explain to me how pluto does not qualify as a planet under the current definition in a way I cannot reasonably argue my way out of, that is literally all I am asking you to do.

I don't. I just believe that under the current definition, pluto counts as a planet. Sure, so do many others from that point of view, but I don't mention them because I don't know enough about them and pluto is an easy, well known, point to rally around.

Also hades is cool, but that doesn't influence my astronomical opinion that much.

[Through the Living Hopper He/Him]

14 minutes ago, CoderDrag0n8 said:

IT LITERALLY CAN BE! Just define things better! Like, it must have a mass greater than x kilograms or tons! It must orbit a star is actually a pretty dope one!

I DIDN'T MEAN THEY WERE REMOVED USE CONTEXT CLUES! They "didn't qualify"? Explain to me how pluto does not qualify as a planet under the current definition in a way I cannot reasonably argue my way out of, that is literally all I am asking you to do.

I don't. I just believe that under the current definition, pluto counts as a planet. Sure, so do many others from that point of view, but I don't mention them because I don't know enough about them and pluto is an easy, well known, point to rally around.

Also hades is cool, but that doesn't influence my astronomical opinion that much.

First, how is an ARBITRARY mass limit less subjective?

Second, here's a great Reddit response that I think explains it really well:

Quote

As we discovered more objects in the outer solar system (like Eris, which appeared larger than Pluto at the time), we realized that we needed a clear set of rules to distinguish between planets and the thousands of other large objects orbiting the sun. The criteria are as follows:

The object must orbit the sun, which pluto does.

It must have enough mass to assume a nearly round shape, which pluto also passes.

It must have "cleared the neighborhood" around its orbit. This means a planet must be gravitationally dominant in its orbital path, and such will absorb, eject or capture (as moons) smaller objects. If we take any planet, its mass is the overwhelming majority of all the mass in its orbital path. For example the earth is roughly 1-2 million times the mass of the remaining debris in its orbit not accounting for the moon. Pluto, however, lives in the kuiper belt and only accounts for about 7% of the total mass of the objects in its orbit and so isn't "gravitationally dominant".

 

[CoderDrag0n8 He/They]

1 hour ago, Through the Living Hopper said:

First, how is an ARBITRARY mass limit less subjective?

Second, here's a great Reddit response that I think explains it really well:

 

First, arbitrary != subjective

I mean subjective as in Ambiguous (Definition: having more than one possible meaning)

Second, that actually makes a lot of sense, why doesn’t the actual definition say gravitationally doninant?

[KaladinsSenseOfHumourSpren He/Him]

5 hours ago, CoderDrag0n8 said:

If, according to the definition, we should have 50 planets, than we have 50 planets, and someone needs to change the definition, not "oh no, we'll just pretend these things don't count as planets and now we have a nice round number of 8!"

Well... technically...

And then later:

So yeah, the current definition is actually meaningless, IAU already decided what is a planet and what is not

[Through the Living Hopper He/Him]

8 hours ago, CoderDrag0n8 said:

I mean subjective as in Ambiguous (Definition: having more than one possible meaning)

But... that's not what subjective means. I'm glad we cleared up this miscommunication.

Sidenote, while trying to find the definition on the IAU website, I stumbled upon this:

https://www.minorplanetcenter.net/

@KaladinsSenseOfHumourSpren, where are you getting those screenshots?

[KaladinsSenseOfHumourSpren He/Him]

9 hours ago, Through the Living Hopper said:

Sidenote, while trying to find the definition on the IAU website, I stumbled upon this:

https://www.minorplanetcenter.net/

Yeah everything that isn't a planet or moon has a designation

Ceres is 1 Ceres

Then there's 4 Vesta

Pluto is 13 thousand something something something I think

9 hours ago, Through the Living Hopper said:

 

@KaladinsSenseOfHumourSpren, where are you getting those screenshots?

https://iauarchive.eso.org/static/resolutions/Resolution_GA26-5-6.pdf