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Large Planet discovered outside Pluto

Posted by: koxinga - Sat Jul 30, 2005 8:48 am
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Large Planet discovered outside Pluto 
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Post    Posted on: Wed Aug 03, 2005 5:05 pm
Perhaps the best thing is to "grandfather" Pluto in as king of the kuipers and still refer to it as a planet--what with an atmosphere and a moon and spherical shape. Anything smaller gets called a planetoid--anything Pluto sized or larger gets called a planet. If its lumpy--it gets called an asteroid until it orbits a larger body--at which time it is called a moon.


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Post    Posted on: Thu Aug 04, 2005 12:38 pm
And now we come to the argument of what to call an "atmosphere": pretty much every body has a few wisps of gaseous material floating around it.

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Post    Posted on: Fri Aug 05, 2005 11:52 am
Hello, spacecowboy,

what you say may be coming up seriously:

Astronomers as well as the people are used to an atmosphere being bound to a planewt or even a body in general - and now they detected an atmosphere at Enceladus which is not bound to that moon but refreshed permanently.

And as if that weren't sufficient - astronomers and the people are also used to an atmosphere being nearly uniformly distributed around a body and now this is not the case at Enceladus.

What about if a planet is found around a star currently surrounded by a cloud as thick as an atmosphere?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

(PS: I avoid to think about what will be if primitive life would be found in such unusual atmosphere-like environments...)


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Post    Posted on: Mon Aug 08, 2005 2:35 pm
Y'know, sometimes I gotta wonder how that Webster dude actually managed to do it. We can't even get a satisfactory definition for the words "planet" or "atmosphere", much less a satisfactory one-word name for a vehicle that follows a parabolic trajectory with the apex at a point more than 100km from sea level but does not have the capability to enter into a true orbit; this guy wrote a whole freakin' book.

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Post    Posted on: Thu Aug 24, 2006 2:02 pm
The debate is ended somehow - the IAU voted for a definition according to which Pluto is not a planet no more but a dwarf planet.

The definition consists of the effects of the physical property gravity. Only round bodies that can or could incorporate or eject material surrounding it are called planets while round bodies that can or could NOT do that are dwarf planets. All bodies else are neither planets nor dwarf planets.

This si reported by the article "BREAKING NEWS: Pluto Demoted, No Longer a Planet" ( www.space.com/scienceastronomy/060824_p ... ition.html ).



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Post    Posted on: Thu Aug 24, 2006 5:10 pm
Ekkehard Augustin wrote:
The debate is ended somehow - the IAU voted for a definition according to which Pluto is not a planet no more but a dwarf planet.

The definition consists of the effects of the physical property gravity. Only round bodies that can or could incorporate or eject material surrounding it are called planets while round bodies that can or could NOT do that are dwarf planets. All bodies else are neither planets nor dwarf planets.

This si reported by the article "BREAKING NEWS: Pluto Demoted, No Longer a Planet" ( www.space.com/scienceastronomy/060824_p ... ition.html ).



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


That's simply silly. It's gay to say it, it's even gay to suggest it but it is simply silly. No other english word that i know off would describe it better.

Not that i don't want change or hate to see pluto called a pluton or a dwarf planet. Beside, what the hell is a dwarf-planet? Isn't that a planet to? Like a kid is a human to, if he is 2 years old or 50.

Beside, we know the earth is not round at all. It's kinda spherelike. Never mind, it is simply silly.


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Post    Posted on: Fri Aug 25, 2006 10:24 am
Hello, Stefan Sigwarth,

I find it to be nonsense also - to some degree at least - because the main reason of the debate and the decision is the growing number of planetary objects. As if the definition is an instrument simply to limit the work and to move some of the work about planets onto the shoulders of other astronomers or even scientists that are no planetologists.

But the criterions are physical ones at least and of natural scientific kind.

But the astronomers are opponing also as can be read in the article "Pluto Demoted: No Longer a Planet in Highly Controversial Definition" ( www.space.com/scienceastronomy/060824_p ... ition.html ):

Quote:
"I'm embarassed for astornomy," said Alan Stern, leader of NASA's New Horizon's mission to Pluto and a scientist at the Southwest Research Institute. "Less than 5 percent of the world's astronomers voted."

"This definition stinks, for technical reasons," Stern told SPACE.com. He expects the astronomy community to overturn the decision. Other astronomers criticized the definition as ambiguous.


Quote:
Stern, in charge of the robotic probe on its way to Pluto, said the language of the resolution is flawed. It requires that a planet "has cleared the neighborhood around its orbit." But Earth, Mars, Jupiter and Neptune all have asteroids as neighbors.

"It's patently clear that Earth's zone is not cleared," Stern told SPACE.com. "Jupiter has 50,000 trojan asteroids," which orbit in lockstep with the planet.

Stern called it "absurd" that only 424 astronomers were allowed to vote, out of some 10,000 professional astronomers around the globe.

"It won't stand," he said. "It's a farce."

Stern said astronomers are already circulating a petition that would try to overturn the IAU decision.

Owen Gingerich, historian and astronomer emeritus at Harvard who led the committee that proposed the initial definition, called the new definition "confusing and unfortunate" and said he was "not at all pleased" with the language about clearing the neighborhood.

Gingerich also did not like the term "dwarf" planet.

"I thought that it made a curious linguistic contradiction," Gingerich said in a telephone interview from Boston (where he could not vote). "A dwarf planet is not a planet. I thought that was very awkward."

Gingerich added: "In the future one would hope the IAU could do electronic balloting."




Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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Post    Posted on: Fri Aug 25, 2006 1:15 pm
It isn't so strange as it seems. Until yesterday, there was no official, scientific, definition of what constitutes planet. People keep saying they have redefined what a planet is, but they haven't REdefined it, they just DEfined for the first time. The only problem is that it upsets people who have been calling Pluto a planet for 66 years. But astronomers have been arguing about Pluto since the time it was discovered. The only reason this has come to a head now is the discovery of so many other objects orbiting beyond Neptune, making a continuum of objects down to a size nobody would call a planet. They had to draw the line somewhere, and clearly Pluto was on the wrong side of any scientifically valid line.

This is really no different than what happened with the asteroids. When Ceres was discovered in 1801, it was considered a planet. Then Pallas, Juno and Vesta were discovered and people started to get uneasy. Then, starting in 1845, dozens more were discovered, so Ceres and all the new small objects were assigned to the newly defined class of "asteroid". Ceres had been a planet for 50 years, in text books and everything, and they changed that in the face of the new data. That is what science does, changes the thinking when new data shows the error in the old thinking.


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Post my definition of a planet   Posted on: Fri Aug 25, 2006 4:10 pm
Here's my proposed definition:

Any object orbiting the a star that is more massive or larger than the largest moon of any other planet.

- Using mass as a descriminator, we'd have 8 planets- Pluto being eliminated. Ganymede, Titan, Callisto, Io, the Moon, Europa, and Triton are all more massive. -- See List of solar system objects by mass
- Using size as a descriminator, we'd have 7 planets- both Mercury and Pluto being eliminated. Ganymede and Titan being larger than Mercury and Callisto, Io, the Moon, Europa, Triton and possibly 2003UB313 are all larger than Pluto. -- See List of solar system objects by radius.

Of course there are the problems of planets around brown dwarfs, objects not orbiting any stars, etc...

My two cents.

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Post    Posted on: Fri Aug 25, 2006 5:53 pm
That sounds OK except for the possibility of demoting Mercury. Pluto was not discovered until 1930 and we should have known better than to call it a planet then, but Mercury was considered a planet before the Earth was! Any definition that demotes Mercury is out, IMO.


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Post    Posted on: Mon Aug 28, 2006 4:19 am
The whole debate is silly, an object is what it is, regardless of how we categorize it. Pluto is a unique object with unique properties. It doesn't matter whether you call it a planet, dwarf planet, KBO or asteroid. If you need to talk about it, you talk about its particular properties, NOT those typical of its 'kind'. We are talking about an object over 2000 km wide, with its own geography and (possibly) weather, not a pebble picked up on a beach.

Pluto doesn't care what you call it! :roll:


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Post    Posted on: Tue Aug 29, 2006 4:52 pm
campbelp2002 wrote:
That sounds OK except for the possibility of demoting Mercury. Pluto was not discovered until 1930 and we should have known better than to call it a planet then, but Mercury was considered a planet before the Earth was! Any definition that demotes Mercury is out, IMO.


That's why I like the method of using mass rather than size.

I'd love a simple definition that kept Pluto as a planet. Of course, Pluto-Charon could be a binary planet, but where would you draw the line after that?

WannabeSpaceCadet wrote:
The whole debate is silly, an object is what it is, regardless of how we categorize it. Pluto is a unique object with unique properties. It doesn't matter whether you call it a planet, dwarf planet, KBO or asteroid. If you need to talk about it, you talk about its particular properties, NOT those typical of its 'kind'. We are talking about an object over 2000 km wide, with its own geography and (possibly) weather, not a pebble picked up on a beach.


I disagree in so far as that we do need define what a planet (etc.) is. The public will want to know what to call the newer objects we find around other stars.

One would have thought that scientists would have been more concerned about the properties rather than what "kind" of object it is. However the IAU, at least in the media, does care about the "kind".

Reality is probably more along the lines of poor media relations (or the lack of thought about how the media would react.)

For example, take the Near-Earth Object community. Every time there is an asteroid on potential collision course, the media go nuts. Of course, it turns out that the potential is based on insufficient observations and eventually the probability decreases and the NEO community look like Chicken Little again.

Scientists need to be cognizant of how the public and media will react to big scientific announcements. It should not change the nature of the announcement, but it should force them to be careful on how they word their announcements.

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Post    Posted on: Tue Aug 29, 2006 8:28 pm
alistair wrote:
I'd love a simple definition that kept Pluto as a planet. Of course, Pluto-Charon could be a binary planet, but where would you draw the line after that?
As I see it, the only silly part is that astronomers are bowing to public pressure to keep Pluto a planet instead of demoting it to a Kuiper Belt Object like they really should.

I am fond of Pluto too. One reason it was quickly called a planet is that it was initially believed to be bigger than Mars, but now we know that it is smaller than the Moon. Also, it is in a pretty eccentric and inclined orbit that crosses Neptune's orbit. A lot of asteroids cross planet orbits but if Pluto is a planet it is the only one that crosses another planet's orbit. Then along comes 2003 UB313, Sedna, 2003 EL61, 2005 FY9 and others. So we are now entering the same territory that Ceres experienced in the 1800s. Ceres was listed as a planet in astronomy books and tables (along with Pallas, Juno and Vesta) for about half a century until further asteroids were discovered. Ceres turned out to be disappointingly small for a planet so Herschel coined the term "asteroid" ("star-like") to describe it.


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Post    Posted on: Wed Aug 30, 2006 1:18 pm
And I might point out that poor media relations aren't always the scientists' fault. Take your NEO example, Alistair. Those guys are doing exactly what they're supposed to do: when they find a previously unknown object, they call up their local newshounds and state just that: "there's an new object that looks like its orbit might intersect Earth's; we're doing more research and we'll keep you posted." They send out a bulletin to the rest of the NEO community to watch this object to find out more about it.

And then, by the next day, their phones are ringing off the wall from the idiot reportes wanting to know how long we have until the end of the world. And even though they try to fight back (at least, the new guys do), saying "We haven't stated that it will collide with Earth, just...." "But it will cross Earth's orbit, right?" "Maybe, we haven't done enough observations to be...." "Right, and how big is it?"........ You see the point. The media itself can be perfectly impossible to deal with at times, especially when it thinks it's dealing with scientists. Reporters generally consider scientists to be too stupid to understand the importance of a good story, so they just steamroll right over them.

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Post    Posted on: Wed Aug 30, 2006 4:02 pm
spacecowboy wrote:
And I might point out that poor media relations aren't always the scientists' fault. Take your NEO example........

<snip>

You see the point. The media itself can be perfectly impossible to deal with at times, especially when it thinks it's dealing with scientists. Reporters generally consider scientists to be too stupid to understand the importance of a good story, so they just steamroll right over them.


Good point. The media is largely to blame. They want sound bites and don't bother looking into the supporting info. Doesn't help that the public at large don't look beyond the media talking heads.

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