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Pluto: A 'Planet' Or Not?

On a tangent - I searched for Eris Andys on the imdb, because of her repeated assertions of being a scriptwriter/in the movie business, but couldn't find a clue. Did she write for FT under a pseudonym?
 
It suddenly ocurred to me to wonder what effect this might have on the 'extended' versions of Holst: The Planets. There's a Simon Rattle version here that appears to include not only Pluto but Ceries and a couple of others:

Disc: 1
1. Mars, The Bringer Of War
2. Venus, The Bringer Of Peace
3. Mercury, The Winger Messenger
4. Jupiter, The Bringer Of Jollity
5. Saturn, The Bringer Of Old Age
6. Uranus, The Magician
7. Neptune, The Mystic
8. Pluto, The Renewer

Disc: 2
1. Asteroid 4179: Toutatis
2. Towards Osiris
3. Ceres
4. Komarov's Fall
 
Excellent! If ever there was sign that discordians everywhere should rise up and ... erm ... tell greyface what time it is, in some way, er perhaps, this must surely be it!!!!
 
So the planet once known as 2003 UB313, Planet X and Xena, is now officially "Eris". Suitably named after the Greek goddess of confusion. She has one moon, named after one of Eris' daughters; Dysnomia.

ALICIA CHANG
Associated Press

LOS ANGELES - A distant, icy rock whose discovery shook up the solar system and led to Pluto's planetary demise has been given a name: Eris.

The christening of Eris, named after the Greek goddess of chaos and strife, was announced by the International Astronomical Union on Wednesday. Weeks earlier, the professional astronomers' group stripped Pluto of its planethood under new controversial guidelines.
Since its discovery last year, Eris, which had been known as 2003 UB313, ignited a debate about what constitutes a planet.

Astronomers were split over how to classify the object because there was no universal definition. Some argued it should be welcomed as the 10th planet since it was larger than Pluto, but others felt Pluto was not a full-fledged planet.

After much bickering, astronomers last month voted to shrink the solar system to eight planets, downgrading Pluto to a "dwarf planet," a category that also includes Eris and the asteroid Ceres.

Eris' discoverer, Michael Brown of the California Institute of Technology, said the name was an obvious choice, calling it "too perfect to resist."

In mythology, Eris caused a quarrel among goddesses that sparked the Trojan War. In real life, Eris forced scientists to define a planet that eventually led to Pluto getting the boot. Soon after Pluto's dismissal from the planet club, hundreds of scientists circulated a petition protesting the decision.

Eris' moon also received a formal name: Dysnomia, the daughter of Eris known as the spirit of lawlessness.
Eris, which measures about 70 miles wider than Pluto, is the farthest known object in the solar system at 9 billion miles away from sun. It is also the third brightest object located in the Kuiper belt, a disc of icy debris beyond the orbit of Neptune.

Eris had been without a formal name while astronomers grappled over its status. Brown nicknamed it "Xena" after the fictional warrior princess pending an official designation. He admits the new name will take some getting used to.

"It's a little sad to see Xena go away," he said.

Seems there are now 8 "planets", and 3 "dwarf planets" (Ceres, Pluto, and Eris)

Ah well, one up for the Discordians anyway!
 
From World Wide Words newsletter:
ERIS? WHO SHE? The dwarf planet officially known as 2003UB313, the
one that orbits beyond Pluto and whose discovery led to the latter
being dethroned as a major member of the stellar in-crowd, has now
been given its permanent name. Everyone has been calling it Xena,
the nickname its discoverer Mike Brown gave it, which he took from
the name of a character in a television show. But both he and the
International Astronomical Union thought this wasn't classy enough
for a permanent name and the IAU has accepted his suggestion of
Eris. She's a figure from Greek classical mythology, the goddess of
strife. Considering the furore over the heavenly status of Pluto,
it's an appropriate name. Its moon is now officially Dysnomia after
Eris's daughter, whose name means "lawlessness". Every commentator
has noted that in the TV series Xena was played by Lucy Lawless.
8)
 
More bad news for downgraded Pluto

· Dwarf planet is not even the biggest of its type
· Eris, body that reopened debate, is heavier

Alok Jha, science correspondent
Friday June 15, 2007
The Guardian

Astronomers have announced yet more bad news for the much-lamented former planet Pluto. Kicked out of the club of planets last year into a new category of dwarf planet, it is not even the biggest of those, scientists have found.
The same object that began Pluto's problems, a 1,500-mile-wide dwarf planet called Eris, has been confirmed as bigger and heavier than Pluto.

Using the Hubble space telescope and the Keck observatory in Hawaii, scientists used measurements of the orbit of Dysnomia, one of the satellites of Eris, to calculate that Eris is 27% heavier than Pluto. "This is sort of Pluto's last stand," said Emily Schaller, of California Institute of Technology, part of the research team that publishes its results today in Science.

Pluto was demoted from planet status at a meeting of the International Astronomical Union last year. The move solved an embarrassing fudge: when astronomers at the Lowell observatory announced the discovery of Pluto in 1930, they claimed it was several times larger than Earth, ensuring that it was quickly labelled the ninth planet. But as it turned out, Pluto was substantially smaller than the moon. At 1,480 miles, its width is no more than the distance from London to Moscow.
When Eris was spotted on the edge of the solar system in 2003, it forced astronomers to rethink their definition of what made a planet. Ian Crawford, of the Centre for Planetary Science and Astrobiology at Birkbeck College, said the latest research showed that the discovery of Pluto had been a lucky accident: rather than a proper planet, he said, Pluto had just been the first object discovered from the Kuiper Belt, a ring of rocks and comets that surrounds the outer solar system. "It goes to show that there's nothing special about Pluto."

The objects in the Kuiper Belt, which include Pluto and Eris, and the mysterious Oort cloud, which includes Halley's comet,were formed 4bn years ago at the birth of the planets. They interest scientists because they preserve a record of conditions at that time, which is useful in understanding the origins and formation of the solar system.

Andrew Coates, of the Mullard space science laboratory at University College London, admitted to a tinge of sadness when Pluto was reclassified. "I, like everyone else, had grown up through school thinking Pluto was a planet [but] science has moved on, it's definitely a Kuiper Belt object, and getting that idea across to schoolkids now gives them more of a chance of understanding the solar system in the future."

He said there was no reason to think that Eris was the most impressive object in the outer solar system. "It's certainly possible there are bigger objects out there."

Owen Gingerich, emeritus professor of astronomy and history of science at Harvard-Smithsonian centre for astrophysics, said that astronomers were already tracking several new candidates for dwarf planet status. Within a few years, he predicted, the solar system was likely to have five or six new members.

http://www.guardian.co.uk/space/article ... 10,00.html
 
'Non-planet' Pluto gets new class

"Plutoid" is the word of the moment for astronomers.

It is the new classification that has been sanctioned for the object that was formerly known as the "ninth planet".

It is nearly two years since the International Astronomical Union (IAU) stripped Pluto of its former status as a "proper" planet.

Now an IAU committee, meeting in Oslo, has suggested that small, nearly spherical objects orbiting beyond Neptune should carry the "plutoid" tag.

As astronomy's official nomenclature organisation, the IAU must approve all new names and classifications.

Pluto's relegation was felt necessary because new telescope technologies had begun to reveal far-off objects that rivalled the world in size.

Without a new classification, these discoveries raised the prospect that textbooks could soon be talking about 50 or more "planets" in the Solar System.

That prospect proved too much for IAU members who took the historic decision to redefine the Solar System to have just eight major worlds - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

They relegated Pluto to a grouping that includes Ceres (the largest asteroid), and Eris, an object slightly larger than Pluto that orbits even further out from the Sun in an icy region known as the Kuiper Belt.

The IAU's Committee on Small Body Nomenclature has now decided that dwarf planets that move beyond Neptune should be placed in a new sub-category, the plutoid.

More plutoids

In a statement released on Tuesday, the IAU further explained the plutoid definition as celestial bodies that "have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared [their orbits of debris].

"The two known and named plutoids are Pluto and Eris. It is expected that more plutoids will be named as science progresses and new discoveries are made."

The plutoids will also need to have a minimum brightness.

Ceres will not be considered a plutoid because of its position in the asteroid belt between Mars and Jupiter.

The classification will not placate those incensed by Pluto's demotion.

Alan Stern, a former Nasa space sciences chief and principal investigator on a mission to Pluto, was scathing in his condemnation of the IAU.

"It's just some people in a smoke-filled room who dreamed it up," he told the Associated Press. "Plutoids or haemorrhoids, whatever they call it. This is irrelevant."

http://news.bbc.co.uk/1/hi/sci/tech/7449735.stm
 
Here we go again.... :roll:

Planetary storm over status of Pluto
Campaign seeks to overturn ruling that split the world of astronomy
By Steve Connor, Science Editor
Saturday, 3 January 2009

The number nine has a special significance for Mark Sykes, director of the Planetary Science Institute in Tucson, Arizona. Nine is the number of planets in the Solar System, and Sykes is one of several leading astronomers who want to keep it that way.

Unfortunately, the International Astronomical Union (IAU), which adjudicates on these matters, has ruled there are no longer nine planets in the Solar System, after a decision two years ago to downgrade Pluto to the lowly status of a "dwarf planet".

But in 2009, Dr Sykes and his like-minded colleagues hope to get the ruling overturned at the next general assembly of the IAU, to be held in Rio de Janeiro in August.

"The IAU is not the Holy Mother Church, so its pronouncements are not followed by everybody," said Dr Sykes. "To me and many like me, Pluto remains a planet and there are still nine planets in the Solar System.

"The one thing that was particularly bad about the IAU's decision is that normally it makes pronouncements that are a mark of a general consensus, but here it has tried to impose its view on the rest of us."

The row over Pluto's downgrading has been simmering since the astronomy organisation voted to relegate it in August 2006 in Prague. It was agreed at the last vote of that conference – after many scientists had left.

It was particularly galling for Alan Stern, principal investigator on a Nasa mission, New Horizons, which had launched a nuclear-powered probe to Pluto six months earlier.

Dr Stern and Nasa found that their £460m New Horizons spacecraft, due to arrive at Pluto in 2015, was no longer going to visit the Solar System's most distant planet, but just one of many chunks of rock in the Kuiper belt of asteroids beyond Neptune.

"The IAU definition is so flawed on so many levels," Dr Stern fumed. "It's an awful definition; it's sloppy science and it would never pass peer review."

Nasa states: "Most people call Pluto a planet because it orbits the Sun and it is large enough for its own gravity to pull it into a spherical shape."

Pluto is a strange world: its surface is frozen at about minus 233C – just 40 degrees above the "absolute zero" of minus 273C – and it is so far from the Sun that its daytime could be compared to Earth during a full moon night. In fact, there is a strong scientific case for calling Pluto something other than the name given to the eight other planets, which fall either into the terrestrial "rocky" planets, notably Earth, Venus, Mercury and Mars, or the Jovian "gaseous" planets of Jupiter, Saturn, Uranus and Neptune.

"Pluto is just one of the largest members of the Kuiper belt of objects – the dregs of planet formation," said Hal Levison of the South Western Research Institute in Boulder, Colorado who has studied the dynamics of planet definition.

In other words, Pluto is just one of many large icy bodies around the Sun. The IAU has a new term, "plutoid", for such objects, which, while massive enough to form a near-spherical shape, do not have gravitational influence to clear the neighbourhood around their orbit of other objects.

"If you took Earth out of the Solar System, the other planets would care. If you took Pluto out, it would make no difference to the orbits of the other planets," said Dr Levison. Dr Sykes disagrees: "Pluto is far more like Earth than Earth is like Jupiter. Jupiter is a gas planet. It doesn't even have a surface or topography, unlike Pluto."

Both men, though, believe the argument over Pluto is more than an arcane discussion for experts. Astronomy and science are about organising observations of nature and a major aspect of this is how scientists agree on a system of classification.

"The argument over Pluto is a demonstration that scientists can disagree and that science is not some dictatorial project – it's dynamic," said Dr Sykes. "I think if the IAU changes its mind, that would be fine. If it doesn't, its credibility will be harmed."

Earth's most distant neighbour

1930 The year Pluto was discovered by the American astronomer Clyde Tombaugh

3,600 Pluto's average distance (in million miles) from the Sun

247.9 Years it takes Pluto to orbit the Sun

-233C Astronomers' estimate of the temperature on its surface

http://www.independent.co.uk/news/scien ... 22862.html

It ain't over till the fat lady sings... whoever she may be in this case! ;)
 
Even higher up the WTF? scale...

Illinois declares Pluto is still a planet
Three years ago, the astronomy community voted to downsize the solar system by revoking Pluto's planetary status. Now the land of Lincoln is fighting back

Every now and then a story comes along that seems to be true in spite of every cell in your brain telling you it can't be. Welcome to one of those stories.

In 2006, you'll remember that the International Astronomical Union announced that Pluto was to be expelled from the planetary club, reducing the number of planets in the solar system to eight. Cue mayhem in schools, where teachers were obliged to rip up wallcharts and console their pupils, who were understandably forlorn at the fate of their favourite planet.

In their wisdom, the IAU came up with a new class of heavenly body, "dwarf planet", which would include Pluto. Dwarf planets, incidentally, are not planets that are dwarfy. They are something completely different, the IAU said.

The new definition was such a kluge that the chair of the IAU's own planet definition committee, Owen Gingerich, said:

We now have dwarf planets which are in fact not planets. I consider this a linguistic catastrophe.

It seems that the insult to Pluto has been too much to bear for the good people of Illinois. State documents declare that Pluto was unfairly downgraded, and that the decision to demote the poor planet resulted from a vote involving only 4% of the IAU membership.

As such, the Illinois state governors have resolved to take action and reinstate Pluto as a planet. What's more, they have announced their intention to name Friday 13 March 2009 "Pluto Day", to mark its discovery in 1930 by Clyde Tombaugh, who happened to be born on a farm in the state. :roll:

It's all wonderful, if deeply baffling stuff. Why is this happening? Whatever your views on Pluto's rightful status, it's heartening to see that the fate of that small rock, and so the size of the solar system, is still up in the air.

http://www.guardian.co.uk/science/blog/ ... o-a-planet
 
New Scientist has an interesting article on retrograde exoplanets:
http://www.newscientist.com/article/mg2 ... 827911.000
(You need to be registered or a subscriber to read it.)

But as an appendix to the article, it has this interesting snippet which brings us back to little Pluto in our solar system:


Backwards moon

Neptune is the farthest planet from the sun and home to the only backwards moon of substantial size in the solar system. While Neptune spins one way on its axis, its largest moon, Triton, circles the planet the other way.

Large moons form out of the debris swirling around a newborn planet, so they should circle in the same direction as the planet's rotation. The fact that Triton, whose diameter is one-fifth that of the Earth, does not circle in this way suggests that its origins lie elsewhere.

The obvious place is the Kuiper belt, a distant band of icy rubble left over from the birth of the planets. Growing up on the edge of the Kuiper belt, the infant Neptune could easily have encountered Kuiper belt objects and snared one for its moon. The trouble is that a body as massive as Triton could be captured only if it was moving improbably slowly.

There is a way around this, say Craig Agnor of Queen Mary, University of London, and Douglas Hamilton of the University of California, Santa Cruz. Triton had a companion. Agnor and Hamilton's simulations show that, in a three-body encounter with Neptune, Triton could have lost speed at the expense of its companion, which was ejected (Nature, vol 441, p 192).

Such an encounter is not unimaginable, and many Kuiper belt objects are known to be binaries. The missing culprit could be Pluto. It is about the same size as Triton and its orbit crosses Neptune's. Conceivably, Pluto and Triton are brothers.

Which was nice! ;)
 
Neil deGrasse Tyson covers all this quite nicely in his recent book (and accompanying PBS show) The Pluto Files. (http://www.amazon.com/Pluto-Files-Ameri ... 599&sr=1-1)

It's quite readable and I saw him give a nice talk this year at GW in DC. He talks about the competing theories, Pluto's history and special place in the hearts of people the world over and even mentions the letters of abuse he received from school kids over his role in the reclassification. A recommended read!
 
Hes a great guy, isnt he?

Im studying Astronomy GCSE at the moment (quite by accident)

My Teacher says that every asteriod is twinned with a potato.
 
That trumps my rather pathetic Big Bang Theory clip! :lol:

So, you were there, were you? :D
We need to hear more. ;)
 
Yes, I was down the front on the left!

I follow Tyson's Tweets and he mentioned that it was upcoming at Howard University (apparently they have a Secular Students Society - who knew), so I grabbed some free tickets and took a long lunch break!

Great talk, I thoroughly recommend watching the video. Dawkins doesn't really mention his Atheism at all, it's just an astrophysicist and a evo-biologist having a lighthearted talk about their respective fields. Religion only comes up at the end when some guy tried to burn Dawkins with a zinger and got taken down by Tyson instead!

Well worth a watch and well worth taking a 2 hour lunch break!
 
escargot1 said:
That trumps my rather pathetic Big Bang Theory clip! :lol:

So, you were there, were you? :D
We need to hear more. ;)

To be fair, there's not much that can trump Big Bang Theory ;)

rev_dino said:
Yes, I was down the front on the left!

I follow Tyson's Tweets and he mentioned that it was upcoming at Howard University (apparently they have a Secular Students Society - who knew), so I grabbed some free tickets and took a long lunch break!

Great talk, I thoroughly recommend watching the video. Dawkins doesn't really mention his Atheism at all, it's just an astrophysicist and a evo-biologist having a lighthearted talk about their respective fields. Religion only comes up at the end when some guy tried to burn Dawkins with a zinger and got taken down by Tyson instead!

Well worth a watch and well worth taking a 2 hour lunch break!

Thank you for the link; that's my post-cake-marzipanning coffee break viewing sorted :D
 
Mike Brown: The astronomer who slayed planet Pluto
When Brown discovered a distant world called Eris, he didn't realise it would see Pluto kicked out of the Solar System – and his letterbox fill with hate mail. Nick Harding meets him
Friday, 7 January 2011

Mike Brown is an unlikely destroyer of worlds, but then again it was never his intention to kill off an entire planet. It was an accident. His original plan was to discover a new one, and he nearly did. However, scientific logic intervened and the astronomy professor who bears more of a resemblance to Bill Gates than he does to Darth Vader will go down in history as the man who killed Pluto.

Brown, who was once described by Time magazine as potentially "the most successful planet hunter in the history of the Solar System," did not need a Death Star for his act of cosmic annihilation; a relatively simple telescope sufficed. With it he redrew our understanding of our star system, demoting Pluto from its exalted planetary status to that of a lowly "dwarf planet". It happened four years ago, but he still receives hate mail from "Pluto-huggers". 8)

Pluto's undoing began when Brown embarked on a survey of the outer reaches of the Solar System, in and beyond an area called the Kuiper Belt which stretches past the orbit of Neptune and consists of ice and rock bodies preserved from the time of the Sun's creation. His obsessive quest uncovered several large objects of which one, Eris, appeared larger than Pluto and presented the international astronomical community with a dilemma; was it a planet? If not, it would have to follow that neither was Pluto.

The resulting debate about what constitutes a planet and the final decision to downgrade Pluto caused a firestorm of controversy, most of which was directed at Brown who argued strongly against the case for Pluto and consequently his own status as a space-age Christopher Columbus.

"I knew classing Eris as a planet was a very bad idea," explains Brown. "The word planet is not trivial; it should be reserved for the most important objects in our Solar System. I discovered a lot of small things out past Neptune, they are scientifically very interesting but if I found 10 objects similar to Eris, their combined mass would not add up to that of the biggest moon of Neptune. It would have been wrong to class Eris as a planet.

"There was a cartoon view of the Solar System where Pluto is only a little bit smaller than the earth and Jupiter is only a little bit larger than the Earth. In the view that a lot of people grew up with, Pluto is a prominent part of the solar system, but that is not the actual Solar System."

In truth, Pluto's planetary credentials were in doubt long before Brown's discoveries. Discovered in 1930 by American astronomer Clyde Tom- baugh, it was initially believed to be as big as the Earth, but is now known to be smaller than the moon. In 2000 its battle for survival began in earnest when Neil deGrasse Tyson, an influential astrophysicist at the American Museum of Natural History in New York, designed an exhibit which omitted it from the Solar System.

He explains: "In the mid-90s researchers were discovering new objects in the outer solar system, objects that were small like Pluto, icy like Pluto, with elongated orbits like Pluto, and we thought to ourselves, maybe it's not that Pluto was the ninth planet. Maybe Pluto was the first object of a new class of objects that populates this outer zone in the Solar System."

...

Between December 2004 and March 2005 Brown found the other three largest objects in the Kuiper belt, and one of them, Eris (originally nicknamed Xena after the television female warrior), appeared bigger than Pluto. It gave the International Astronomical Union (IAU), mankind's arbiter of planetary order, a dilemma and the body convened in Prague in August 2006 to debate whether Eris and Brown's other discoveries were planets.

"Either they were going to declare me to be the discoverer of more planets than anyone else in human history or not. :shock: I felt like I had so much personally at stake that the best thing for me to do was stay as far away from it as possible," recalls Brown, who fled to a remote island off the north-western coast of the US and followed the debate online. However, when the IAU made an initial proposal to accept Eris as the tenth planet, Brown realised he had to act for the sake of accuracy, despite the consequences.

"I knew a decision to demote Pluto would cause a public outcry and the IAU knew demoting Pluto would incur public ire; everybody loves Pluto. They knew the most convenient thing to do would have been to keep things the way they were, but as someone deeply concerned with education and public understanding I couldn't sit by and watch that happen," says Brown.

"I had always believed that it didn't make sense that Pluto was a planet and knew I would be getting hate mail from schoolkids if Pluto did get kicked out the Solar System."

Eventually, on August 25, a rebel faction of astronomers made a counter-proposal to place Eris and Pluto under a new classification; Dwarf Planet. Brown lobbied in support of this alternative view and the IAU reluctantly accepted it. The Solar System was redrawn and text books were revised (Brown maintains publishers were pleased for the extra business). For Brown, the pro-Pluto hate mail continues almost daily. He sighs: "These days the 13-years-olds who were mad back in 2006 have grown up and gone to college and started drinking so I get 3am obscene messages on my office line, which are really quite funny."

etc...

http://www.independent.co.uk/news/scien ... 77993.html
 
That was the sound of me sharpening my axe.

Dont worry, it was only my pocket hatchet (11 inches long and 3/4lb weight) as he only likes the very small things...
 
Pluto's rival is tinier but shinier than thought
http://www.newscientist.com/blogs/short ... t-shi.html
18:37 13 October 2011
Space
Lisa Grossman, reporter


Pluto may be the king of the dwarfs after all. New observations confirm that Eris, the dwarf planet whose discovery got Pluto kicked out of the planet club in 2006, is almost exactly the same size as Pluto – and may be a bit smaller.

When Eris was discovered in 2005, images from the Hubble Space Telescope suggested that it was 2400 kilometres wide, 5 per cent wider than Pluto, which is only about 2340 kilometres wide. Later observations with the infrared Spitzer Space Telescope made Pluto's case even worse, finding Eris's diameter to be around 2600 kilometres.

But both measurements left room for doubt. Last November, astronomers got a chance to know for sure which rock ruled the outer solar system, when Eris passed directly in front of a distant star and cast a small shadow on the Earth.

Bruno Sicardy of the Paris Observatory and colleagues compared the shadow's size from two different sites in Chile, and found that Eris's diameter is 2326 kilometres, reported Scientific American's Observations blog. That's hardly different from the best values for Pluto's size.

"It could be smaller, it could be larger; basically, it is a twin," Sicardy said at the meeting, according to the Planetary Society Blog. Sicardy presented the results at the Division of Planetary Sciences meeting in Nantes, France, on 4 October, and they will be published in an upcoming issue of Nature.

Could the results cause astronomers to rethink Pluto's demotion? "No," says Mike Brown at Caltech, who led the team that discovered Eris. "Which one is slightly bigger than the other is not terribly relevant, which is clear from the fact that people weren't clamoring for Eris to be a planet when it appeared bigger than Pluto."

Eris is still the dwarf planet heavyweight, though. It is much more massive than Pluto, meaning it is substantially denser. That suggests Eris is mostly composed of rock, with a relatively thin icy mantle. Models of the solar system's composition at various distances suggest it should have had a thicker layer of ice if it formed where it is. If so, much of its original ice may have been blasted away in a catastrophic impact, reports MSNBC's Cosmic Log.

The new observations also revealed that the dwarf planet is brighter than fresh snow, and possibly the second brightest object in the solar system, after Saturn's icy moon Enceladus. That hints at a surface layer of nitrogen or methane frost, the remnants of a collapsed atmosphere which goes through a cycle of freezing and thawing as the small world wheels around the sun.
 
Pluto Strikes Back!

The little wanderer seems to be gaining ground is the struggle to be a planet again.


Now, Tyson's points are valid, and some of the reasoning sound. Pluto is a very odd object, with an eccentric orbit(it often is actually inside the orbit of Neptune) and a very, very long year.

However, Pluto was granted status as a planet. It has several moons, including one so large it tempts the description of a double planet. The orbit is a mess, but the more we learn about the Solar System the stranger it becomes-there are asteroids with moons,, and with rings, one has a tail like a comet.


And what is more bizarre than a gas giant, a planet with no actual planet(as in a surface). There is no there, there. Never was.

Thus I say we ought to return Pluto to the roster of planets, on the basis of long usage, and let Ceres head up the dwarf planet scrum.

Oh, yes, and don't you think the next planet discovered ought to be named Yuggoth, in honor of HP Lovecraft?

Meanwhile, little Pluto is about to be visited by a spacecraft, and some of the any mysteries brought to light. including the moon Charon.

Great days for science!

JUSTICE FOR PLUTO!
 
How long before they reinstate Pluto as a planet, I wonder?
Not going to happen. Pluto is a very interesting, well-imaged, dwarf planet, which should really have a different type name, along with a growing number of other such objects, some even larger than Pluto.
 
Not going to happen. Pluto is a very interesting, well-imaged, dwarf planet, which should really have a different type name, along with a growing number of other such objects, some even larger than Pluto.
New research suggest Pluto should be reclassified as a planet

Should Pluto be reclassified a planet again? UCF scientist Philip Metzger says yes based on his research. Credit: NASA
The reason Pluto lost its planet status is not valid, according to new research from the University of Central Florida in Orlando.

In 2006, the International Astronomical Union, a global group of astronomy experts, established a definition of a planet that required it to "clear" its orbit, or in other words, be the largest gravitational force in its orbit.

Since Neptune's gravity influences its neighboring planet Pluto, and Pluto shares its orbit with frozen gases and objects in the Kuiper belt, that meant Pluto was out of planet status.However, in a new study published online Wednesday in the journal Icarus, UCF planetary scientist Philip Metzger, who is with the university's Florida Space Institute, reported that this standard for classifying planets is not supported in the research literature.

Metzger, who is lead author on the study, reviewed scientific literature from the past 200 years and found only one publication—from 1802—that used the clearing-orbit requirement to classify planets, and it was based on since-disproven reasoning.

He said moons such as Saturn's Titan and Jupiter's Europa have been routinely called planets by planetary scientists since the time of Galileo.

"The IAU definition would say that the fundamental object of planetary science, the planet, is supposed to be a defined on the basis of a concept that nobody uses in their research," Metzger said. "And it would leave out the second-most complex, interesting planet in our solar system.""We now have a list of well over 100 recent examples of planetary scientists using the word planet in a way that violates the IAU definition, but they are doing it because it's functionally useful," he said."It's a sloppy definition," Metzger said of the IAU's definition. "They didn't say what they meant by clearing their orbit. If you take that literally, then there are no planets, because no planet clears its orbit."

The planetary scientist said that the literature review showed that the real division between planets and other celestial bodies, such as asteroids, occurred in the early 1950s when Gerard Kuiper published a paper that made the distinction based on how they were formed.

However, even this reason is no longer considered a factor that determines if a celestial body is a planet, Metzger said.

Study co-author Kirby Runyon, with Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, said the IAU's definition was erroneous since the literature review showed that clearing orbit is not a standard that is used for distinguishing asteroids from planets, as the IAU claimed when crafting the 2006 definition of planets.

"We showed that this is a false historical claim," Runyon said. "It is therefore fallacious to apply the same reasoning to Pluto," he said.Metzger said that the definition of a planet should be based on its intrinsic properties, rather than ones that can change, such as the dynamics of a planet's orbit."Dynamics are not constant, they are constantly changing," Metzger said. "So, they are not the fundamental description of a body, they are just the occupation of a body at a current era."

Instead, Metzger recommends classifying a planet based on if it is large enough that its gravity allows it to become spherical in shape.

"And that's not just an arbitrary definition, Metzger said. "It turns out this is an important milestone in the evolution of a planetary body, because apparently when it happens, it initiates active geology in the body."

Pluto, for instance, has an underground ocean, a multilayer atmosphere, organic compounds, evidence of ancient lakes and multiple moons, he said.

"It's more dynamic and alive than Mars," Metzger said. "The only planet that has more complex geology is the Earth."
 
I've heard the argument before that any relatively spherical body should be called a planet, including what we now consider moons.
Titan is the only solid-bodied object that has Earth-like weather, thus very dynamic and "alive", so by those criteria it could be reclassified as well. Even funkier, it likely has two sets of liquid - the methane on the surface and sub-surface water ocean. I wonder if they interact in any way?
What I expect is that, over time, a much broader spectrum of astronomical body shapes, rotations, and relationships, are going to be found around other stars that causes another round of reclassifications changing what names to use and how to group them.
 
Bolded "planet" in my previous post was a result of my failure to remove cached gsearch formatting, and not a crude attempt, through repeated emphasis, to impress upon readers the full planetary stature of Pluto.:)


Should Pluto Be a Planet Again? Informal Vote Offers Support After Experts Debate

By Elizabeth Howell April 30, 2019

A friendly debate about Pluto's planethood yesterday (April 29) ended in an informal vote that came down in favor of reinstating the dwarf planet's status.

Early in the morning Eastern time, after a livestreamed Philosophical Society of Washington discussion earlier that evening, Alan Stern — principal investigator of the New Horizons mission that flew by Pluto — tweeted that his argument won the vote, which was open to anyone who could access the PSW website, even those who were not members. Results showed 130 people voted in favor of making Pluto a planet and 30 were against. During the debate, Stern argued in favor of using a geophysical definition to define planethood. Briefly speaking, this suggests that planets must be those bodies massive enough to assume a nearly round shape but not massive enough to have nuclear fusion in the interior (like a star).

But since 2006, the International Astronomical Union, represented in the debate by former IAU president Ron Ekers, has used another definition for planethood, which excludes Pluto. This definition says a planet must orbit the sun, must have a nearly round shape and must have "cleared the neighborhood around its orbit." Historically, it's that third point that has caused the most contention among Pluto planethood advocates, given the number of asteroids orbiting near even the larger planets.
The debate over Pluto's planetary status intensified after the New Horizons mission flew by the dwarf planet in 2015. New Horizons revealed a world of surprises: large mountains, a possible internal ocean and a tenuous "exosphere" or very thin atmosphere. Given Pluto's complex geology, Stern and some other members of the astronomical community began arguing that Pluto should be designated as a planet once more.
On the naming of things

The debate went over the points in detail for and against Pluto being a planet. Ekers' presentation focused on the history of the IAU, which was originally formed in 1919 to coordinate clocks and issue reports via telegram about findings related to astronomy.
"Coordinating all the clocks that are in the world is not itself science, but if we don't do that, it makes the pursuit of science difficult; it's a practical function, which these international unions have to do," Ekers said.
By the same token, he argued, assigning categories to planets is also not science, but a way of describing objects so that scientists can communicate. Other examples of this type of decision include agreeing on constellation names and boundaries, or describing species (such as humans, or homo sapiens) by their genus and a specific name.
Pluto was discovered in 1930, amid a search for a planet that was believed to be causing irregularities in the orbit of Neptune, Ekers said. Pluto was too small to cause these perturbations, and later calculations showed that the first calculations of Neptune's orbit were incorrect. But it was a lucky find nonetheless. The diminutive Pluto was closer to the sun at that point in its orbit than it is now and easier to spot in telescopes available at the time.
It wasn't until six decades later that other objects close to Pluto's size were discovered in the Kuiper Belt, a region of icy objects beyond Neptune. Then Mike Brown, an astronomer at the California Institute of Technology, led the discovery of an object called 2003 UB313 that was believed to be larger than Pluto. "No name could be assigned [by the IAU] because there was no planet definition," Ekers said. (Today, we know that world by the name Eris.
The IAU twice asked the planetary systems division to come up with a definition of a planet; with the experts gridlocked, the IAU formed a naming committee that included both international representation and people working within and outside of planetary science (such as historians and educators).

The committee asked that their discussions not be made public, which Ekers acknowledged may have been a mistake, but he added that media were invited (and present) at the decision that made Pluto a dwarf planet.

The vote took place at the August 2006 IAU meeting in Prague, which included 424 voting members (out of a total membership of 9,000). The majority vote was for Pluto to be redesignated as a dwarf planet, along with a number of other "trans-Neptunian objects" discovered in the few years before the vote. A separate resolution, suggesting that dwarf planets should be named planets, failed by a large margin, he added.
"This is not a vote about science," Ekers said. "The vote at the IAU is about an agreement on how you name things, and that was an important difference."

Stern then took the stage, outlining what he saw as issues with the IAU vote. He brought up the matter of expertise in the IAU planet definition committee, arguing it should have been made up of planetary scientists: "If, God forbid, somebody here was diagnosed with a neurological problem, I would hope you would go to a neurologist and not a podiatrist, or some other form of doctor, because expertise does matter.
He provided a quick historical overview of three "game changers" that were fundamental to what he called the "dwarf planet revolution": the discovery that oceans are common on other bodies in our solar system, the discovery of the Kuiper Belt of icy objects that show what the solar system looked like early in its history and the discovery of small worlds such as Pluto — most of which were not found until the early 21st century.
Visitors — perhaps aboard the USS Enterprise of "Star Trek" — would look at Pluto and say that they are orbiting a planet, Stern said. "It has an atmosphere made of the same stuff we are breathing," he argued. He cited its mountain ranges, glaciers, avalanches and "all the hallmarks of planetary processes" visible on the surface.

He also took Ekers to task on two points regarding the IAU. Stern argued that the IAU deliberately engineered the planetary definition so that it would be easier to memorize the number of planets in the solar system — Ekers responded that if Stern heard that, it was probably a joke made at the time of the decision. Stern also said no planet can fully clear its orbit of debris as it circles the sun, while Ekers argued that the asteroids and comets that we do see are in resonance (in orbits coincident) with planetary orbits.

Stern also argued that farther out in the solar system, it is harder to clear away small objects because they move so much slower in their orbits around the sun than do objects that are closer due to the nature of how orbits work. This means that planets need to be more and more massive in the outer reaches of the solar system to clear away small objects. Even Earth wouldn't qualify as a planet if you moved it out to 100 Earth-sun distances from the sun — "It just breeds confusion," Stern said.

Stern and Ekers shook hands after the debate and shared a question and answer period with the audience, in which they further clarified their positions. While Pluto's planethood status didn't change following the debate, it does form part of a larger set of studies and questions that continue — even nearly 13 years after Pluto was designated a dwarf planet.
 
Imagine you're Pluto. Waaaay out there by the heliopause. Cold and alone. Only a couple of half-arsed krispy kremes for company.

You check your cellphone. It indicates that those invisible protein shakers stuck to the blue dot down near Sol have taken the bureaucratic mandate to rescind your planet status. With a sigh your head drops and all the enthusiasm you had mustered for the impending return of your Voyager buds (there's another inevitable crock) goes out your anus in a fluff of fudgegas.

[QUOTE-]"I mean it's not like I asked for anything special, right. Nobody blinks an eye when those bullies across the way bleedin' demand 60-odd in their audience on their riders ... fkn moons, no less! Like wtf, man. Come on. Those little shits they just wave your license in your face for a few of their pissy little decades, and then it's all like "oh Oh OH! Psych!". I never asked for any of it. Thanks for my fifteen minutes, Andy. asshole"[/QUOTE;]


Come on. Give the guy a break, fer chrissakes. It's christmas.
 
Pluto is much smaller than our moon, and barely large enough to generate enough gravity to hold a spherical shape. Pluto is really an ice dwarf, and so wears lots of furs, has an especially woolly beard, and favors harpoons over axes.
 
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