August 16, 2006

12 planets.

They didn't want to hurt the feelings of Pluto-lovers, so they picked a definition for planet that would include Pluto, and, doing that, they let in 3 more rocks. The nonconformingly named 2003 UB313 (AKA Xena). Charon, which is a moon, which is annoying. And Ceres, ceresly. Wouldn't it have been pleasanter to just oust Pluto? Come on, scientists! If you want to make us feel good, make us feel good!

39 comments:

Balfegor said...

If Charon gets to be a planet, why not Titan (bigger than Mercury or Pluto) or Ganymede? And if Ceres, why not Juno or Pallas? They're big asteroids too. This makes no sense!

GSH said...

Charon gets to be a planet because it does not revolve around Pluto, exactly. The two of them are a binary system, and both revolve around a center of mass that exists outside either body.

Brian O'Connell said...

Because the center of gravity of the Titan/Saturn system is below Saturn's surface. The article mentions that this disqualies the moon.

SippicanCottage said...

And Ceres, ceresly.

Ann, you're a wag.

Dorothy Paker got nuthin' on you.

bill said...

If they're including asteroids, then I vote for B612. Three active volcanoes, a rose, and a baobab tree it has a lot more going for it than Pluto.

Dave said...

Angels dancing on the head of a pin, IMHO.

Of more import: creating more scientifically literate people.

Dave Schuler said...

Public relations. It's easier to get into the newspapers when you discover a planet in another solar system than if you discover a rock in another solar system.

Michael Farris said...

"They didn't want to hurt the feelings of Pluto-lovers"

Damned degenerate Pluto-lovers, it's about time we locked 'em all up.

Tibore said...

"Wouldn't it have been pleasanter to just oust Pluto?"

But what about Mickey and Goofy?

... sorry, couldn't resist...

Steven said...

I note that in the case of Ceres, it's not a promotion, it's a restoration. Ceres was considered a planet when first discovered and named.

I find the barycenter-under-surface-of-a-planet restriction unsatisfying. The reason is Jupiter -- the Sun-Jupiter barycenter is above the surface of the Sun. Logically applying the rule, then, would make Jupiter a Sun-level body in the Solar SYstem, not a planet-level body (for the same reasons the rule moves Charon from moon to planet).

In which case, there'd be 11 Solar planets, and four Jovian planets, the Solar-Jovian System.

Paul Zrimsek said...

They purposely rigged the rules just so they could say "the world Ceres".

Simon said...

Wouldn't it have just made a great deal more sense to just leave well alone? "Scientists debate Plutos planetary status; cancer still not cured." The very fact they're debating such a bizarre non-question suggests that there is fat to be trimmed from the astronomy department's budget.

joeschmo1of3 said...

Steven,

They did discount stars as candidates for planets, but good grab on how arbitrary the new set of rules would be under this proposal.

As a former astrophysics student, I wrote up my own feelings on this mess here, if anyone wants to get a rambling response to this ridiculous waste of researchers' time.

Icepick said...

Dave Shuler wrote: Public relations. It's easier to get into the newspapers when you discover a planet in another solar system than if you discover a rock in another solar system.

FYI: Extra-solar planets that have been discovered are big, usually in the Jovian class. There is no debate about those planets, or their status. In fact, their immense size is that reason they can be discovered at all.

Steven wrote: I find the barycenter-under-surface-of-a-planet restriction unsatisfying. The reason is Jupiter -- the Sun-Jupiter barycenter is above the surface of the Sun. Logically applying the rule, then, would make Jupiter a Sun-level body in the Solar SYstem, not a planet-level body (for the same reasons the rule moves Charon from moon to planet).

No, Jupiter would not be a 'Sun-level' body, because it is not a star - no fusion at work in the core, and none in the past, either.

Simon wrote: Wouldn't it have just made a great deal more sense to just leave well alone? "Scientists debate Plutos planetary status; cancer still not cured." The very fact they're debating such a bizarre non-question suggests that there is fat to be trimmed from the astronomy department's budget.

No, it does not make more sense to leave well enough alone. The definition of "planet" has been poor ever since Galileo turned his telescope towards Juptier and discovered that it had satellites. I'm not sure that this new definition is terribly good (the 800K diameter and 1/12,000 the Earth's mass sound somewhat arbitrary), but some standardization of the definition would be very helpful.

As for the snide comment that "Scientists debate Plutos planetary status; cancer still not cured", I offer an even more snide comment. If your knowledge of science leads you to think that astronomers are (or should be) the folks working on a cancer cure, then perhaps you should take a few remedial classes on several subjects before offering an opinion on the budgets of astronomy departments.

Joan said...

JoeSchmoe, I read your proposed guidelines and it seems you're really hanging onto the gaseous atmosphere idea, saying that Pluto would still be included as a planet. According to these guys, it's not clear that Pluto has a gaseous atmosphere at all, although there is a lot of water ice present. In addition, saying that Mercury "supports" a gaseous atmosphere is also kind of a stretch.

I don't have a problem with the new guidelines per se. I am amused at the minor hissy fits this will cause, though -- lots of mnemonics will have to be updated, and a lot of kids' educational shows will become instantly wrong. I will be a little sad if the Blue's Clues Planet Song has to be retired... even my 4th-grader still hums it occasionally when asked to list all the planets in order.

joeschmo1of3 said...

Hey Joan,

Yeah, Mercury has what we call an exosphere, where the atoms never collide, so, by "definition" it's a gas. I told you I hate this stuff. I also think that we should boot Pluto straight out of there because it's orbit isn't even in the orbital plane of the solar system, which is why it's sometimes closer to the sun than Neptune. We used to think it was a captured comet, but, the planetologist should be the ones deciding what's a planet, not this ad hoc committee that's making all members vote on the question of new bodies being planets or not.

JorgXMcKie said...

Hey, these guys are 'super serial' about this. And, icepick, don't some astronomers and/or astrophysicists regard Jupiter as a failed 'proto-star' or something like that? I.e., if it had been a bit bigger it would have ignited?

Mike said...

Schools aren't the only place with grade inflation.

Simon said...

Icepick said...
"Simon wrote: 'Wouldn't it have just made a great deal more sense to just leave well alone?'

No, it does not make more sense to leave well enough alone. The definition of "planet" has been poor ever since Galileo turned his telescope towards Juptier and discovered that it had satellites.
"

The mere fact that the definition of what a planet is may well have been fuzzy for several hundred years, and perhaps that might suffice as an argument against naming a new body as a planet, but in no event does it rise to the level needed to displace - or even disturb - an understanding followed and widely understood since 1930. There are nine planets in this system, Pluto being one of them; if astronomers wish to change their criterion for subsequent admissions to that class, then they are more than welcome to do so.

joeschmo1of3 said...

Jorg:

Jupiter has been compared to a brown dwarf, but it's mass is (probably) too low to be classified as such. However, it is massive enough that it radiates more light energy (especially in the radio, microwave, and infrared wavelengths) than it receives from the sun. So, not a brown dwarf, although it's as big as one, but still a radiating body. Have I told you how much I hate this stuff?

Smilin' Jack said...

While the barycenter of the Earth-Moon system currently lies about 900 miles beneath the surface of the Earth, tidal forces cause the Moon to slowly move away from the Earth, by a few centimeters per year. So in a few billion years the barycenter will rise above the Earth's surface, and the Moon will be promoted to planethood. Imagine the celebrations!

Drew W said...

Jupiter may have been compared to a brown dwarf . . . and I bet George Allen's staffers are pretty relieved that he wasn't the one to do it.

Mike said...

"They didn't want to hurt the feelings of Pluto-lovers"

I have to admit to always having a soft spot for poor old Pluto.

Pogo said...

Gordie: Mickey is a mouse, Donald is a duck, Pluto is a dog. What's Goofy...?
Teddy: He's a dog, he's definitely a dog...
Chris: He can't be a dog, he wears a hat and drives a car...
Vern: Yeah, that is weird. What the hell is Goofy?

Icepick said...

The mere fact that the definition of what a planet is may well have been fuzzy for several hundred years, and perhaps that might suffice as an argument against naming a new body as a planet, but in no event does it rise to the level needed to displace - or even disturb - an understanding followed and widely understood since 1930. There are nine planets in this system, Pluto being one of them; if astronomers wish to change their criterion for subsequent admissions to that class, then they are more than welcome to do so.

So Pluto is a planet because everybody says so? Brilliant.

"What's the definition of a planet?"

"A planet is any of nine celestial bodies that circle the Sun."

"Do only nine celestial bodies circle the sun?"

"No."

"Then what are the other things called?"

"Moons, asteroids, comets."

"So what makes them different than planets? Are they smaller than planets?"

"No, some of them are bigger than planets."

"Are they shaped differently than planets?"

"Some of them, but many have the same roughly sperical shape as a planet."

"Well then, do they go around the Sun in triangular patterns or something?"

"Not really, no."

"So why are planets planets, and not comets, asteroids, moons or whatnot?"

"Because everybody says they are planets."

"Why does everyone call them planets?"

... long pause ...

"Ours go up to nine...."

Astronomy, as taught by Nigel Tufnel....

John A said...

"... 2003 UB313 (AKA Xena),..."

Cool, a planet for we fans of the Xena: Warrior Princess" show!

lucas m. said...

As a tip of the hat to home state loyalty, I say we keep Pluto a planet. A lot of the research that led to the discovery of Pluto was done right here in Arizona at the observatory on Mars Hill in downtown Flagstaff.
We don't have a lot of famous people and things that come out of AZ(Sandra Day O'Connor not withstanding) , lets not take one of our biggest!

Wickedpinto said...

All of these decisions should not be entrusted to people who are affraid of correcting their definitions no matter how faulty their new definitions are going to be.

I suggest all new definitions about all solar and stellar objects should be left to the judgement of the big fuzzy driver of "The Great Space Coaster" and don't trust any news releases that aren't offered by Gary GNu, where no Gnews, is good Gnews.

but call me a freak. All genius is neglected by their contemporaries before understood by history.

Rusty said...

The word on the subject by Christine Lavin:

http://www.christinelavin.com/022200planetx.html

This song contains the first URL ever contained in a song.

Steven said...

Jupiter . . . is not a star - no fusion at work in the core, and none in the past, either.

Right. But size and orbit are independent variables, and while it's not size-wise a star, it is orbit-wise an equal of the Sun in the same sense that, orbit-wise, Charon is an equal of Pluto.

Take two sets of variables.

The first is size of body, and that would give you a breakdown of stars (big enough for fusion), "middelos" (big enough to be gravitationally spheroidal), and "tinyos" (the rest of the stuff).

The second is "orbital barycenters", and the definitions would seem to be

Category 1: "none inside anything"; Category 2: "inside an object that itself belongs to the first category";
Category 3: "inside an object that itself belongs to the second category";
Category N: "inside an object that itself belongs to the N-1th category".

Under the proposed definition of "planet", it reduces to "middelo of orbital category 1 or 2". So why 1 and 2, but only 1 and 2?

Well, apparently only because if we limited it to orbital category 2, Jupiter would cease being a planet and become something else, while if we included 3 through N, the Moon would become a planet. So to preserve the status quo, we've got this definition that has no physical justification, or even excuse.

Johnny Nucleo said...

I've been working on this problem for years. The solution is to destroy Pluto. My calculations indicate it could be done for less than a trillion dollars. But when I went to NASA with my proposal they threw me out!

Ole said...

How about Quaoar and Sedna? I feel bad for them :I

Revenant said...

I also think that we should boot Pluto straight out of there because it's orbit isn't even in the orbital plane of the solar system

There is no "orbital plane of the solar system". None of the 8 original planets share a common orbital plane. Their orbital planes just differ by a lot less than that of Pluto.

In any case, why should having a weird orbit disqualify Pluto? Why not, say, angle of rotation (Uranus is odd man out), or atmosphere (Mercury loses), or the presence of a solid surface?

Also, if orbit is the qualifier, Ceres would still make the list of planets.

somross2 said...

I like the girl (or semi-girl) names: Ceres, Xena (even if it gets changed later), and Charon. Apparently although Charon is usually pronounced like "Karen" because of the Greek "Ch" sound when this possible planet is discussed it's pronounced "Sharon" because discoverer Christy wanted it to sound more like his wife Charlene's name. (And so it doesn't sound like the mythological male character who ferried people after death to the netherworld?) I vote for "Sharona."

Jacob said...

Here's a special message to all who don't think Pluto should be a planet

joeschmo1of3 said...
This comment has been removed by a blog administrator.
joeschmo1of3 said...

Revenant:

Um, look here for a good description of how individual planets' orbital planes oscillate perpendicular to the solar system's invariable plane. The oscillations are so small compared to the scale of the solar system's size, that the invariable plane and average orbital plane are treated, for most intents and purposes, as equal. Unless you're actually measuring the oscillation, then I guess it's pretty important. I've mentioned, right, that I hate this stuff?

seattlel said...

Planet X
© 1997 Christine Lavin

In Arizona at the turn of the 20th century
astromathematician Percival Lowell
was searching for what he called "Planet X"
'cause he knew deep down in his soul
that an unseen gravitational presence
meant a new planet spinning in the air
joining the other eight already known
circling our sun up there

But Percival Lowell died in 1916
his theory still only a theory
'til 1930, when Clyde Tombaugh
in his scientific query
discovered Planet X
3 point 7 billion miles from our sun
a smallish ball of frozen rock
methane and nitrogen

It joined Mercury, Venus, Earth, Mars, Jupiter
Saturn, Uranus and Neptune
our solar system's newest neighbor
two-thirds the size of our moon
a tiny, barely visible speck
cold! minus 440 below
not exactly Paradise
they named the planet Pluto

That same year, 1930, Walt Disney
debuted his own Pluto as well
but a cartoon dog with the very same name
as the CEO of Hell
was not your normal Disney style
most figured he was riding the coattails
of Pluto-mania sweeping the land
(not unlike our modern love
for dolphins and whales)

For the next five decades
mysterious Pluto captivated our minds
as late as 1978 its own moon Charon
was seen for the very first time
but now telescopes and satellites
and computer calculations
say that Pluto may not be a planet at all
causing great consternation

(Some scientists say that Pluto is a)...
"trans-Neptunian interloper"
swept away by an unknown force"
or "a remnant of a wayward comet
somehow sucked off course"
others say that "Pluto is an asteroid
in the sun's gravitational pull"
but if you ask Clyde Tombaugh
he'll tell you it's all "bull"

"I get hundreds of letters from kids every year,"
he says, "It's Pluto the planet they love
it's not Pluto the comet, it's not Pluto the asteroid
they wonder about above"
and at The International Astronomical
Union Working Group
For Planetary System Nomenclature
they, too, say that Pluto is a planet
reinforcing Clyde Tombaugh's view of Nature

Norwegian Kaare Aksnes, professor at the
Theoretical Astrophysics Institute
he, too, says that Pluto is still a planet
and a significant one, to boot
but at the University of Colorado
astronomer Larry Esposito
says "If Pluto were discovered today
it would not be a planet. End of discussion.
Finito"

He says that "It was not spun off from solar matter
like the other eight planets we know
by every scientific measure we have
is it a planet? No!"
and now twenty astronomy textbooks
refer to Pluto as less than a planet
I guess if Pluto showed up at a planet convention
the bouncer at the door might have to ban it

St. Christopher is looking down on all this and he
says, "Pluto, I can relate
when I was demoted from sainthood
it didn't feel too great"
and Scorpios look up in dismay
because Pluto rules their sign
is now reading their daily Horoscope
just a futile waste of time?

It takes 247 earth years
for Pluto to circle our sun
it's tiny and it's cold but of all heavenly bodies
it's Clyde Tombaugh's* favorite one
'til he was 92 he worked every day
in Las Cruces, New Mexico
determined to maintain the planetary status
of his beloved Pluto

But how are we going to deal with it
if science comes up the proof
that Pluto was never a planet
how do we handle this truth?
as the Ph.D.'s all disagree
we don't know yet who's wrong or who's right
but wherever you are, whatever you are
Pluto, we know you're out there tonight

And in the year 2003 you're going to see
the NASA Pluto Express
fly by and take pictures
of your way cool surface
to send to this web page address:
http://dosxx.colorado.edu/plutohome.html
you've got own web page?
for a little guy
you've made quite a splash

Yes, at the turn of the 20th century
astromathematician Percival Lowell
in his quest for "Planet X"
started this ball to roll
but at the end of the 20th Century
we think he may have been a little off base
so we look at the sky
and wonder what new surprises
await us in outer space
we look at the sky and we wonder ...

*Sadly, Clyde Tombaugh died in January 1997,
after this song was recorded.
This is the re-written line,
and now whenever I sing it
I look up and smile at Clyde.

seattlel said...

Planet X
© 1997 Christine Lavin

In Arizona at the turn of the 20th century
astromathematician Percival Lowell
was searching for what he called "Planet X"
'cause he knew deep down in his soul
that an unseen gravitational presence
meant a new planet spinning in the air
joining the other eight already known
circling our sun up there

But Percival Lowell died in 1916
his theory still only a theory
'til 1930, when Clyde Tombaugh
in his scientific query
discovered Planet X
3 point 7 billion miles from our sun
a smallish ball of frozen rock
methane and nitrogen

It joined Mercury, Venus, Earth, Mars, Jupiter
Saturn, Uranus and Neptune
our solar system's newest neighbor
two-thirds the size of our moon
a tiny, barely visible speck
cold! minus 440 below
not exactly Paradise
they named the planet Pluto

That same year, 1930, Walt Disney
debuted his own Pluto as well
but a cartoon dog with the very same name
as the CEO of Hell
was not your normal Disney style
most figured he was riding the coattails
of Pluto-mania sweeping the land
(not unlike our modern love
for dolphins and whales)

For the next five decades
mysterious Pluto captivated our minds
as late as 1978 its own moon Charon
was seen for the very first time
but now telescopes and satellites
and computer calculations
say that Pluto may not be a planet at all
causing great consternation

(Some scientists say that Pluto is a)...
"trans-Neptunian interloper"
swept away by an unknown force"
or "a remnant of a wayward comet
somehow sucked off course"
others say that "Pluto is an asteroid
in the sun's gravitational pull"
but if you ask Clyde Tombaugh
he'll tell you it's all "bull"

"I get hundreds of letters from kids every year,"
he says, "It's Pluto the planet they love
it's not Pluto the comet, it's not Pluto the asteroid
they wonder about above"
and at The International Astronomical
Union Working Group
For Planetary System Nomenclature
they, too, say that Pluto is a planet
reinforcing Clyde Tombaugh's view of Nature

Norwegian Kaare Aksnes, professor at the
Theoretical Astrophysics Institute
he, too, says that Pluto is still a planet
and a significant one, to boot
but at the University of Colorado
astronomer Larry Esposito
says "If Pluto were discovered today
it would not be a planet. End of discussion.
Finito"

He says that "It was not spun off from solar matter
like the other eight planets we know
by every scientific measure we have
is it a planet? No!"
and now twenty astronomy textbooks
refer to Pluto as less than a planet
I guess if Pluto showed up at a planet convention
the bouncer at the door might have to ban it

St. Christopher is looking down on all this and he
says, "Pluto, I can relate
when I was demoted from sainthood
it didn't feel too great"
and Scorpios look up in dismay
because Pluto rules their sign
is now reading their daily Horoscope
just a futile waste of time?

It takes 247 earth years
for Pluto to circle our sun
it's tiny and it's cold but of all heavenly bodies
it's Clyde Tombaugh's* favorite one
'til he was 92 he worked every day
in Las Cruces, New Mexico
determined to maintain the planetary status
of his beloved Pluto

But how are we going to deal with it
if science comes up the proof
that Pluto was never a planet
how do we handle this truth?
as the Ph.D.'s all disagree
we don't know yet who's wrong or who's right
but wherever you are, whatever you are
Pluto, we know you're out there tonight

And in the year 2003 you're going to see
the NASA Pluto Express
fly by and take pictures
of your way cool surface
to send to this web page address:
http://dosxx.colorado.edu/plutohome.html
you've got own web page?
for a little guy
you've made quite a splash

Yes, at the turn of the 20th century
astromathematician Percival Lowell
in his quest for "Planet X"
started this ball to roll
but at the end of the 20th Century
we think he may have been a little off base
so we look at the sky
and wonder what new surprises
await us in outer space
we look at the sky and we wonder ...