For the astronomers and astrophysicists amongst us...

[davedove]

Sad really. How many textbooks, lessons, records, etc now need to be changed.

That's nothing new. Science is constantly reclassifying things. I don't know that I agree with their decision, but I do agree with their motive. With all the discoveries of other solar systems and other objects within our own system, they did have to decide what would be classified a "planet". Most of us can agree on a general knowledge of what a planet is, but science has to be defined.

Never fear though. Eventually some new discoveries will cause another decision.:rolleyes:

[Panache]

Last I had heard, they were discussing the issue, but my wife just told me they did indeed downgrade Pluto to another catagory called "mini-planet" or some such nonsense. :rolleyes:

I think the term was "dwarf planet" which makes a catagory for Pluto, Charon, Xena and Sedna and the other planetlets we are likely to find in the future. I think that Ceres will remain an asteroid. For those of you sad that Pluto got downgraded, on the positive side Charon steps up from moon to dwarf planet-Go Team Charon!

Cheers

[SSgt Baloo]

Pluto's just the tip of the iceberg. These astronomers should be stopped before they do any more harm. Who's next on their diabolical list, Goofy?

[cessna152towser]

Panche wrote:-

they did indeed downgrade Pluto to another catagory called "mini-planet" or some such nonsense.

Bureaucrats or Plutocrats?

[bubba]

A prime example of people with way too much free time.

[Panache]

Panche wrote:-

Bureaucrats or Plutocrats?

...somewhere out amongst the billions and billions of star...Carl Sagan weeps.

[Colin]

I am just wondering how my 5 year old will take the news. They just studied the planets in pre-school, and now his younger sister has one less to learn

[auld argonian]

Sent to me by my mon...can't find a simple link to it, so here it is with some formatting strangeness:

I ¢¾ Pluto

By TIM KREIDER

Charlestown, Md.

MY love for our picked-on ninth planet is deeply, perhaps embarrassingly, personal.

I took my first public stand on Pluto¡¯s taxonomical fate when I addressed the Forum on Outer Planetary Exploration in 2001 (don¡¯t ask why a cartoonist was addressing astronomers — it¡¯s a long story).

I informed the assembled scientists that, first of all, no way was I or anyone else about to un-memorize anything we¡¯d already been forced to learn in elementary school. More important, I felt sure that, as former children, we all instinctively respected the principle: no do-overs.

Planets, like Supreme Court justices, are appointed for life, and you can¡¯t blithely oust them no matter how eccentric, skewed or unqualified they may prove to be. If they could kick out Pluto, I warned, they could do it to anything, or anyone.

I admit: it¡¯s a highly emotional issue and maybe I got carried away in the heat of debate.

Even I was a little abashed last week when the International Astronomical Union tried to protect Pluto¡¯s status by proposing an absurdly broad definition of planethood that encompasses moons, asteroids and trans-Neptunian objects — in other words, pretty much any half-formed hunk of frozen crud that can pull itself together into a ball long enough to get photographed by the Hubble.

For longtime Pluto partisans, there was something almost punitive about this proposal: happy now?

I guess I always knew, in my heart, that Pluto didn¡¯t ¡°belong.¡± Pluto is idiosyncratic — neither a dull, domestic terrestrial planet nor a surly, vainglorious gas giant. It¡¯s mostly ice. It¡¯s smaller than our own Moon, and has an orbit so eccentric that it spends 20 years of its 248-year revolutionary period inside Neptune¡¯s orbit. It¡¯s tilted at a crazy 17-degree angle to the ecliptic, and its satellite, Charon, is so disproportionately large that it¡¯s been called a double planet.

Pluto is what my old astronomy textbook rather judgmentally called a ¡°deviant,¡± and I¡¯ve always felt a little defensive on its behalf.

I¡¯ve long regarded Saturn¡¯s misty tantalizing moon Titan as the Homecoming Queen of the solar system, courted and fawned over, stringing us along with teasing glimpses under her atmosphere, while Pluto was more like the chubby Goth chick who wrote weird poems about dead birds and never talked to anybody. Still, I just can¡¯t stand by and watch as the solar system¡¯s Fat Girl gets pushed down into ever-more ignominious substrata of social ostracism.

All I really wanted was a little velvet-rope treatment for Pluto. I didn¡¯t expect them to throw open the doors to all this Kuiper Belt riffraff.

It¡¯s like that point when your party¡¯s grown out of control and you look around and ask: Who are these people? Sedna? Xena? Ceres? Ceres is an asteroid, for God¡¯s sake. Why not just make 1997 XF11 or Greenland or Harriet Meiers a planet?

And I am second to no one in my respect for Charon, but come on: it¡¯s obviously Pluto¡¯s moon.

Now they¡¯re proposing to designate it a ¡°large companion,¡± which sounds like the sort of euphemistic legal status the court might grant to Oliver Hardy and can¡¯t be doing Charon¡¯s self-esteem one bit of good. ¡°Longtime companion¡± would have been more dignified and validating.

The solar system is a mess.

The situation this seems most similar to is the inextricably tangled social nightmare that is inviting people to your wedding. You truly want to invite your distant and eccentric but dear old friend Pluto, but this necessarily means inviting his horrible girlfriend, too, plus then maybe you¡¯re obliged to invite all the other people you were both friends with in college, friends he¡¯s still in contact with who will be offended if he¡¯s invited and they¡¯re not but who, frankly, are now boring people with whom you no longer have anything in common.

Some would suggest we just have to be harsh about this and not invite any of them, Pluto included. But these people are forgetting that we already sent Pluto an invitation, 76 years ago. Pluto has rented a tuxedo.

The astronomical union is to vote on Pluto tomorrow. But even as astronomers squabble, I remain confident that this whole wonky state of affairs will not be permanent. Eventually we¡¯ll get it all sorted out.

For the record, I would accept a separate (but equal!) class of dwarves or planetoids, including Sedna and Xena. After all, the childhood mnemonic is easily amended: My Very Energetic Mother Just Served Us Nine Pizzas, Sans Xenophobia.

But what I really wish is that we¡¯d just grandfather Pluto in and then close all the loopholes. Let¡¯s do it, not for scientific reasons, but for sentimental ones.

As a friend of mine at NASA said, ¡°It would prove our humanity to let Pluto stay in.¡± It would be like that moment when the doorman is about to escort you out of a private party where you don¡¯t, arguably, belong, but then someone who knows you taps him on the shoulder and says, ¡°Wait a minute, I know this guy. He¡¯s O.K..¡±


...though it was apropo..

Best

AA

[Big Paul]

Political correctness is indeed at an astronomical level these days.

That's bad!!

[Iolaus]

I think the term was "dwarf planet" which makes a catagory for Pluto, Charon, Xena and Sedna and the other planetlets we are likely to find in the future. I think that Ceres will remain an asteroid. For those of you sad that Pluto got downgraded, on the positive side Charon steps up from moon to dwarf planet-Go Team Charon!

Cheers

http://en.wikipedia.org/wiki/Charon_(moon)

Details in the orbits of the outer moons reveal that Charon has approximately 11.65% of the mass of Pluto
[....]
The 2006 "moon or planet?" controversy

Charon had been a part of the controversy over the definition of a planet. Under the draft proposal by the International Astronomical Union, Charon could have potentially been classified as a planet rather than a moon. That (draft) classification may seem counter-intuitive, since a moon is an object that orbits a planet, just as Charon apparently orbits Pluto. However, Charon does not in fact simply orbit Pluto: instead, Pluto and Charon orbit each other around a center of mass that is outside both bodies. The final definition of August 24, 2006 explicitly excluded satellites from the category of dwarf planets

Given that Charon has approximately 11.65% of the mass of Pluto, I'd say that it's Pluto's moon regardless of the relative orbits.

And Pluto's a planet!!!