Illinois Declares Pluto a Planet

[Urwumpe]

Is the IAU prepared to defend its authority in a contest of arms should a challenger arise to reclaim it?

The IAU has 300 MW lasers. Consider this.

 

[n122vu]

Oh by the way... since this is a blog, I wouldn't think it to be 100% accurate... maybe someone is just joking. But I have seen a California bill that kinda did the same thing

Very first sentence on the blog links to this document on the Illinois General Assembly site:
http://www.ilga.gov/legislation/96/SR/PDF/09600SR0046lv.pdf


Also here with site navigation links available:
http://www.ilga.gov/legislation/ful...ID=SR&DocNum=46&LegID=40752&SpecSess=&Session=

**Edit* Can anyone confirm the claim made in the full text of the resolution that states only 4% of the IAU's 10,000 members participated in the vote to demote Pluto from planetary status? Not that I believe it should be reinstated as a planet, but I can see that as a valid complaint from their point of view. I realize that 4% participation may be acceptable if IAU's charter, manifesto, whatever, so decrees, but I can understand why some would feel this wouldn't be a fair process.

 

[Urwumpe]

Can anyone confirm the claim made in the full text of the resolution that states only 4% of the IAU's 10,000 members participated in the vote to demote Pluto from planetary status? Not that I believe it should be reinstated as a planet, but I can see that as a valid complaint from their point of view. I realize that 4% participation may be acceptable if IAU's charter, manifesto, whatever, so decrees, but I can understand why some would feel this wouldn't be a fair process.

Yes, the decision was made by only those IAU members, which took part in the International Astronomic Congress of 2006.

Of over 2,700 astronomers attending the conference, only 424 votes were cast, which is less than 5% of the entire astronomers community. There is also the issue of the many astronomers who were unable or who chose not to make the trip to Prague and, thus, cast no vote. Astronomer Marla Geha has clarified that not all members of the Union were needed to vote on the classification issue: only those whose work is directly related to planetary studies.http://en.wikipedia.org/wiki/IAU_definition_of_planet#cite_note-marlageha-41

 

[BHawthorne]

I declare Pluto is a dog. There is film evidence to back up my claims.

 

[Linguofreak]

If the definition included only being round and primary body around the orbit of the Sun, we'd have to include quite a lot of asteroids into the list of planets.

Well, a dwarf planet is pretty much any object that fits that definition that's not a planet, and so far only one asteroid has been defined as a dwarf planet (Ceres). It's mostly out in the Kuiper belt where that definition leads to lots of objects being declared planets.

---------- Post added at 02:21 PM ---------- Previous post was at 02:21 PM ----------

I declare Pluto is a dog. There is film evidence to back up my claims.

:rofl:

 

[n122vu]

I declare Pluto is a dog. There is film evidence to back up my claims.

Hot dog, hot dog, hot diggity dog....

 

[RocketMan_Len]

Not Vesta or Juno, which aren't in hydrostatic equilibrium and thus aren't on the current list of dwarf planets.

I've never heard the term 'hydrostatic equilibrium' before - would you enlighten me as to its meaning...?

At any rate - I was speaking in the *strictest* sense of what the word 'planet' means. (Greek for 'Wanderer') In that sense, EVERY body in the solar system qualifies... from giant Jupiter to the smallest yet-observed boulder. NONE of them have fixed positions in the night sky, and thus 'wander' about the heavens.

That way, *every* observed body in orbit around the Sun is classed as a 'planet', and everybody is happy.

Until the next time... :rofl:

 

[Zatnikitelman]

If Pluto hasn't cleared its orbit, then why wasn't it some other KBO that was discovered? Why did they recalculate the perturbations on Uranus to indicate that it WAS Pluto and not something else.
Pluto is, and always will be a planet regardless of what a bunch of suits say!

 

[RisingFury]

Well, a dwarf planet is pretty much any object that fits that definition that's not a planet, and so far only one asteroid has been defined as a dwarf planet (Ceres). It's mostly out in the Kuiper belt where that definition leads to lots of objects being declared planets.

A dwarf planet is defined as a round object in primary orbit around the Sun.

A Plutoid is round, trans-Neptunian object, in primary orbit around the Sun.




Other reasons (beyond the definition of the word) why Pluto would make a lousy planet:
- It's orbit is so eccentric, it passes the orbit of Neptune.
- It's inclined far outside of the orbital plane of other planets.
- There are 7 moons in the solar system larger then Pluto.
- If you brought Pluto to where Earth is, it would vaporizer (yes, turn to gas).
- The barycenter of the Pluto-Charon system (the point where these two objects orbit) is outside of Pluto.

Pluto behaves waaaaaay differently then other planets in the solar system do. But Pluto has family out there that behaves like it does. Hey, it even got it's own class of objects, of which it is the prototype - Plutoid. So Pluto is much happier now

 

[Hielor]

- If you brought Pluto to where Earth is, it would vaporizer (yes, turn to gas).

Awesome source of fresh water. Let's tow Pluto to earth!

I would like to see your source, though--according to http://www.windows.ucar.edu/tour/link=/pluto/pluto_composition.html&edu=high it has an iron/rock core, which wouldn't vaporize.

 

[T.Neo]

- There are 7 moons in the solar system larger then Pluto.

If Jupiter had an Earth sized moon, would this make Mars a "lousy planet"?

- If you brought Pluto to where Earth is, it would vaporizer (yes, turn to gas).

Everything is relative; put Earth at a certain distance from the sun and it'll also turn to gas.

- The barycenter of the Pluto-Charon system (the point where these two objects orbit) is outside of Pluto.

This would make Pluto-Charon a double planet, not less of a planet.
If Earth had a moon the size of Mars, would it not be a planet anymore?

 

[Andy44]

It's all semantics and jargon. For strictly scientific purposes, Pluto probably shouldn't be called a planet.

But for everyday talk, and for literary purposes, it's okay to call Pluto a planet, as well as any of the larger bodies, including spherical moons. Earth's moon (Luna) is so big that it would be a contender for the planet title even in science were it in heliocentric orbit. It's craters prove it has done a bit of path-clearing for us, too.

The IAU has no "authority", of course, they are just trying to establish a convention for common use to reduce misunderstandings when discussing space science. You can call Pluto whatever you want. You won't get ticket from the Planet Police.

The IAU has 300 MW lasers. Consider this.

But do be careful...

 

[Linguofreak]

I've never heard the term 'hydrostatic equilibrium' before - would you enlighten me as to its meaning...?

http://en.wikipedia.org/wiki/Dwarf_planet#Size_and_mass

As mentioned in the article, Haumea is defined as a dwarf planet even though it is significantly non-spherical because it is in hydrostatic equlibrium.

In fact, a body with the same mass, density, and rotational angular momentum as Haumea that *was* a sphere would probably *not* be defined as a dwarf planet, since it would not be in hydrostatic equilibrium.

EDIT: BTW, even Jupiter and Saturn are visibly deformed from the spherical by their rotation, but they are in hydrostatic equilibrium.



---------- Post added at 08:03 PM ---------- Previous post was at 07:03 PM ----------

A dwarf planet is defined as a round object in primary orbit around the Sun.

A Plutoid is round, trans-Neptunian object, in primary orbit around the Sun.

You forgot that a dwarf planet has not cleared its orbit. The two criteria you gave define the set of objects that are either planets or dwarf planets. They also define the set of objects that I would prefer to call "planets," which does include the Plutoids.

Other reasons (beyond the definition of the word) why Pluto would make a lousy planet:

Let's try substituting Earth into these situations:

- It's orbit is so eccentric, it passes the orbit of Neptune.

Would people be so quick to say this disqualified an object as a planet if Pluto had the mass (or even the radius) of Earth?

- It's inclined far outside of the orbital plane of other planets.

Incline Earth's orbit 90 degrees to the rest of the solar system. Is it any less a planet?

- There are 7 moons in the solar system larger then Pluto.

If the gas giants between them had seven moons larger than Earth, would that take away the planetary status of Mercury, Venus, Earth, and Mars?

- If you brought Pluto to where Earth is, it would vaporizer (yes, turn to gas).

Probably not entirely, but yes, it would be one big comet. However, an object with the same composition as Pluto and the mass of Earth would behave similarly, although with it's mass, and the attendant high escape velocity, it would probably end up with a very thick atmosphere and a deep ocean, rather than all the volatiles being blown away.

- The barycenter of the Pluto-Charon system (the point where these two objects orbit) is outside of Pluto.

As far as barycenters go:

The Jupiter-Sun barycenter is outside the Sun.

And among planetary/dwarf planetary barycenters the second most offset barycenter in the solar system outside of the Pluto-Charon one is the Earth-Moon barycenter. If the moon were more massive, or further away, or if the Earth were denser, and thus smaller for a given mass, the Earth-Moon barycenter would be outside the Earth.

Barycenter position is a function of the mass of the secondary relative to the mass of the primary, and the distance between the two objects relative to the size of the primary. Even if the planet in question had the mass of Jupiter, and the moon in question had the mass of an electron, the barycenter could (in theory) be outside of the planet just because the moon was far enough away.

Barycenter position might be good for determining double-planet status, but even then I'm doubtful, because of the dependence on distance between the two objects, rather than just on relative masses.

 

[BHawthorne]

I defer to the scientific regulatory authority on the subject. The planetary classification and sexual orientation of Pluto is irrelevant to me. I find it silly people are so entrenched with the whole subject.

 

[RisingFury]

You people took my stuff way out of context.

I'm not saying any of the criteria I mentioned should be included into the "what is a planet" checklist. I'm saying Pluto behaves way differently then other planets do and there's a bunch of objects out there - that aren't planets - that behave just like Pluto does.

I think the strict definition of the word planet was good, but it's still not sufficient. It works well if you apply it to our solar system, but there have been some 300 exoplanets discovered... and Kepler just launched on mission to find Earth like planets in other solar systems.
We're gonna need additional definitions to include types of planets. You can't have one word that describes Jupiter be the same as the one that describes Pluto.

If I discover a new planet, you're gonna ask me 20 questions: How big is it, how massive is it, does it have rings, is it gas giant, is it a small rock, it it an icey body,...
Currently the word planet refers to all, yet it includes no further data.



Did you know that roughly 200 years ago, the planet rooster was up to 13? People started discovering asteroids in the empty region between Mars and Jupiter and each object that was discovered was just considered a planet. But they later realized those objects were in fact very small and behaved way differently then other planets do, which is why the word "asteroid" was invented.
Right now, the same thing has happened: We're discovering other objects other there, that behave differently from the other 8 planets... and yet as a group, they behave roughly the same. So we've invented another word to name them. I can't believe that's so difficult to accept.


@ Hielor:
The composition of Pluto is a guesswork so far. There are sources that will state Iron core and there are sources that will state other compositions. Wiki states a Silicate and water ice core.

The best estimate for it's density comes from google and puts it at around 2 g/cm^3... so even if has an iron core, it's very small.

 

[Kyle]

Personally, If they demoted Pluto they're going to have to Demote Mercury.
Mercury has an elliptical orbit around the sun, and there are moons bigger than it.
Makes as much sense.

 

[RisingFury]

To be a planet, an object has to have a round shape sustained by it's own gravity, has to be the primary object in orbit around the Sun and has to clear it's orbit of orbital debris.

While Mercury is small and has the most elliptical orbit, it does meet the criteria to be planet.

 

[Ghostrider]

The planetary classification and sexual orientation of Pluto is irrelevant to me.

That's because we're talking Pluto. The sexual orientation of Jupiter would be another matter because, let's face it, nobody would dare to pick up the soap anywhere within one AU from Jupiter.

 

[2552]

Personally, If they demoted Pluto they're going to have to Demote Mercury.
Mercury has an elliptical orbit around the sun, and there are moons bigger than it.
Makes as much sense.

Plus, it's inclined 7 degrees to the ecliptic. Only 10 less than Pluto.

 

[Urwumpe]

But Mercury dominates it's orbital neighborhood.