Pluto not a planet?

What do you think about this? (from space.com)


Pluto's Planet Status could be Jeopardized by Sedna Discovery
By Robert Roy Britt
Senior Science Writer
posted: 12:27 pm ET
17 March 2004



The discovery of a nearly Pluto-sized object way out beyond the known
worlds could jeopardize the status of Pluto as a planet, adding fresh
fuel to an argument among astronomers that is likely to last years.

In the end, our solar system will either shrink to eight planets, grow
to more than a dozen, or contain a glaring asterisk born of an
emotional attachment to the diminutive Pluto.



The object announced this week, called Sedna, adds impetus to an
effort by the International Astronomical Union (IAU) to define just
what is and is not a planet. The IAU has no specific plans to directly
challenge the planetary status Pluto. But the decision by a working
group within the IAU could have that effect, an official said today.

"Whether or not one needs to do anything about Pluto will depend on
what the definition of a planet will be," Iwan Williams, president of
the IAU's Planetary Systems Sciences division, told SPACE.com.

The process could fester into 2006, when the group holds its next
General Assembly. And whatever the ruling, there will likely be
astronomers who try to keep the debate alive after that, another
astronomer familiar with the process said.

No definition

Until now, scientists have not had a set definition for the term
"planet." In recent years, many potential parameters have been kicked
about, from an object's roundness to its distance from the Sun and the
shape of its orbit. Even where it formed is a consideration.

"If the answer was obvious, there would be no need for a working
group," Williams said.

The IAU decides on names and classification systems for all solar
system bodies, among other duties. Williams outlined what might happen
in this decision process:

"The specific question of whether Pluto is a planet or not would only
arise if it turned out clearly not to be one by the definition, but
for historical and cultural reasons, the community wished to keep
Pluto as a planet."

Since the 1997 death of Pluto's discoverer, Clyde Tombaugh, many
astronomers have increasingly urged the IAU to downgrade Pluto. The
flap surfaced publicly in 1999 when rumors swirled that Pluto was
going to be stripped of its planetary status. Articles about the
possibility generated widespread public disapproval.

The 1999 fracas was not spurred by the IAU, however, and the
international organization ultimately issued a press release stating
its regret that "incomplete or misleading" press reports on the status
of Pluto "appear to have caused widespread public concern." The
statement went on to assure that "no proposal to change the status of
Pluto as the ninth planet" had been made within the IAU.

Dual status

Many astronomers have since been content to let the IAU and the public
call Pluto a planet, while most of them think of it as a Kuiper Belt
Object, one of many frozen worlds beyond Neptune. Some fight actively
for Pluto's demotion while others think Sedna and its like should join
the cast of planets.

In the meantime, scientists still have not defined planethood and
Sedna, the strange new world, has only increased the need for sorting
out the terms of the solar system.

Sedna is about three-fourths Pluto's size and is presently about three
times as far from the Sun. It ranges much farther into space on a
long, elliptical orbit around the Sun that takes 10,000 years to
complete. It is frigid and almost surely lifeless. But it is round,
like the other planets. It's probably made of rock and ice, though
astronomers don't know its exact composition.

Several astronomers have said that if Pluto is a planet, then Sedna
should be considered a planet.

On the flip side, however, some of those same astronomers prefer the
catchall term "planetoid" for both of these round but small worlds.
Classification systems, they argue, will work themselves out only
after more objects are found and astronomers glean a better
understanding of the suddenly more mysterious outer solar system.

The accident of Pluto

For years most astronomers have said that Pluto is an accident of
observational history and should never have been called a planet.
Pluto was discovered by Tombaugh, an amateur astronomer, in 1930.

"When Pluto was given planet status, its diameter was thought to be
nearly 15,000 kilometers [9,320 miles], 12 percent larger than the
Earth," points out Williams, the IAU official. "In terms of size, it
was the fifth planet rather than the ninth."

And for decades after Pluto's discovery, no other objects were
discovered beyond Neptune. In recent years, however, other round
objects about half Pluto's size have been detected in the Kuiper Belt,
much closer than Sedna. Michael Brown, a Caltech astronomer who led
the discovery of Sedna and two other good-sized worlds, expects there
are more.

In fact, there's even the chance of an Earth-sized planet lurking out
there, he and others say.

Pluto's plight involves many factors. It is about 1,413 miles (2,274
kilometers) wide -- smaller than Earth's Moon. But most astronomers
don't see that as a disqualifying factor.

More significant, Pluto is inclined 17 degrees to the main plane of
the solar system in which the larger planets orbit. Other planets have
inclined orbits, too, but none compare to the leanings of Pluto. It's
orbital path is also very non-circular; it ranges between 30 and 50
astronomical units (AU) from the Sun. One AU is the distance from
Earth to the Sun, about 93 million miles (150 million kilometers).

Senda's travels are even stranger in one sense. It roams from 76 to
1,000 AU. Sedna's inclination is 12 degrees, less than that of Pluto.

"It blurs the line between what is a planet and what is not," said
Alan Boss, a planet-formation theorist at the Carnegie Institution in
Washington DC. It also blurs the line between the Kuiper Belt, where
Pluto resides, and the more distant Oort Cloud, a reservoir of comets
that stretches halfway to the next star.

Scientists have not known what, if anything exists in a possible void
between the two regions. But at the least there is Sedna, officially
catalogued as 2003 VB12. Now they don't know where to stick this
latest discovery. They can't even be sure where it formed, and they're
very unsure as to how it got such an odd trajectory.

"It blurs all sorts of lines," Boss said.

Embarrassing

"It's something of an embarrassment that we currently have no
definition of what a planet is," Gibor Basri of the University of
California, Berkeley, has said. "People like to classify things. We
live on a planet; it would be nice to know what that was."

Basri has previously proposed simply setting a lower diameter limit
for planet status, including all objects orbiting the Sun that are
about 435 miles (700 kilometers) wide or more. That's roughly the bulk
needed to allow gravity to shape an object into a sphere, depending on
density. Smaller objects -- both asteroids and comets -- tend to take
on odd shapes like that of a potato.

Basri's simple definition would boost the tally of planets in our
solar system to more than a dozen based on presently known objects,
including Sedna. And it would leave Pluto as a planet.

Many astronomers, though, simply don't see a solar system with more
than eight planets.

"Scientifically, there really is no question" that Pluto should be
reclassified, says Brown, the Caltech astronomer who helped find
Sedna.

"Either Pluto is not a planet, or many other things are planets,"
Brown said today. "Which is a better choice? I want my planets to be
more special, not less special, so I favor Pluto not being a planet.
Emotionally, though, I have to admit that I have grown up thinking
Pluto this special odd-ball planet at the edge of the solar system.
While I now know scientifically that Pluto is less special, it's still
hard to let go."

Tough job

Whatever the IAU working group decides, the process might stretch out
for two years before any decision is rendered, if at all.

"If it was felt that Pluto required special status, then ratification
at the next General Assembly would be called for," Williams said. That
international IAU meeting will be held in Prague in 2006.

Boss, the Carnegie theorist, is not sure the issue will be settled
even by then.

But Boss does think the IAU's efforts are necessary and worthwhile.
"It sort of sharpens peoples thinking" about how the solar system is
organized, he said. But it won't necessarily silence astronomers who
have strong feelings one way or the other.

"Whoever gets shut out will continue to argue," Boss told SPACE.com.
"I sure would not want to be on the working group myself."

Steve Dufour wrote:
What do you think about this? (from space.com)


Pluto's Planet Status could be Jeopardized by Sedna Discovery
By Robert Roy Britt
Senior Science Writer
posted: 12:27 pm ET
17 March 2004



The discovery of a nearly Pluto-sized object way out beyond the known
worlds could jeopardize the status of Pluto as a planet, adding fresh
fuel to an argument among astronomers that is likely to last years.

In the end, our solar system will either shrink to eight planets, grow
to more than a dozen, or contain a glaring asterisk born of an
emotional attachment to the diminutive Pluto.


They need some solar standards imo, like a mountain is a "hill" that is more
than 1000meters high. Similarly it should be something like 1000Km for the
min diameter.

"Rob" . wrote in message ...
Steve Dufour wrote:
What do you think about this? (from space.com)


Pluto's Planet Status could be Jeopardized by Sedna Discovery
By Robert Roy Britt
Senior Science Writer
posted: 12:27 pm ET
17 March 2004



The discovery of a nearly Pluto-sized object way out beyond the known
worlds could jeopardize the status of Pluto as a planet, adding fresh
fuel to an argument among astronomers that is likely to last years.

In the end, our solar system will either shrink to eight planets, grow
to more than a dozen, or contain a glaring asterisk born of an
emotional attachment to the diminutive Pluto.


They need some solar standards imo, like a mountain is a "hill" that is
more
than 1000meters high. Similarly it should be something like 1000Km for the
min diameter.

Simple. Any limet we set is going to be arbatrary to some extent. You could
simply have anything below Plutos size by say 2% or so is a planetiod. Keeps
people over the age of 25 from being told by 9 year olds that now there is
only 8 planets and we were wrong. Of course that sounds to me like its
drifting into the lets keep it the way we had it because that's the way it
always was.

I guess at some point the characteristics would start to radicly change. As
I understand it Sedna is spherical and was formed in much the same way as
the rest of the solar system. Are other characteristics that different?

Fitzdraco wrote:

I guess at some point the characteristics would start to radicly change. As
I understand it Sedna is spherical and was formed in much the same way as
the rest of the solar system. Are other characteristics that different?

Its orbit around the Sun seems to be far more eccentric than any
other planet's, even counting Pluto.

--
Odysseus

Surely it is /was not a planet!!

1) When it was found, it was used to explain the gravitational distribance
for Neptune, but it is too small. (It means the ninth planet which causes
this effect was not found, so it is why they are looking for the 10th one.)

2) As astronomy advances, many have found the problem of this
classification, because it is clear that it is only a bigger brother of the
planetoids only.

3) The strongest support for Pluto as a planet is ....
tradition! really strong tradtion!
(Don't forget it is an American who found this.)
What's a pity!
Oh! Galileo is used to prove that the Catholic church is too much dependant
on the tradition; but now it is the astronomists who called themselves
'scientists'. (Who should follow evidences, not tradition.) to emphasize the
untouchable tradition: Pluto is a planet (Though it is clear that it is due
to misunderstanding before.(

"Steve Dufour" ???
om ???...
What do you think about this? (from space.com)


Pluto's Planet Status could be Jeopardized by Sedna Discovery
By Robert Roy Britt
Senior Science Writer
posted: 12:27 pm ET
17 March 2004



The discovery of a nearly Pluto-sized object way out beyond the known
worlds could jeopardize the status of Pluto as a planet, adding fresh
fuel to an argument among astronomers that is likely to last years.

In the end, our solar system will either shrink to eight planets, grow
to more than a dozen, or contain a glaring asterisk born of an
emotional attachment to the diminutive Pluto.



The object announced this week, called Sedna, adds impetus to an
effort by the International Astronomical Union (IAU) to define just
what is and is not a planet. The IAU has no specific plans to directly
challenge the planetary status Pluto. But the decision by a working
group within the IAU could have that effect, an official said today.

"Whether or not one needs to do anything about Pluto will depend on
what the definition of a planet will be," Iwan Williams, president of
the IAU's Planetary Systems Sciences division, told SPACE.com.

The process could fester into 2006, when the group holds its next
General Assembly. And whatever the ruling, there will likely be
astronomers who try to keep the debate alive after that, another
astronomer familiar with the process said.

No definition

Until now, scientists have not had a set definition for the term
"planet." In recent years, many potential parameters have been kicked
about, from an object's roundness to its distance from the Sun and the
shape of its orbit. Even where it formed is a consideration.

"If the answer was obvious, there would be no need for a working
group," Williams said.

The IAU decides on names and classification systems for all solar
system bodies, among other duties. Williams outlined what might happen
in this decision process:

"The specific question of whether Pluto is a planet or not would only
arise if it turned out clearly not to be one by the definition, but
for historical and cultural reasons, the community wished to keep
Pluto as a planet."

Since the 1997 death of Pluto's discoverer, Clyde Tombaugh, many
astronomers have increasingly urged the IAU to downgrade Pluto. The
flap surfaced publicly in 1999 when rumors swirled that Pluto was
going to be stripped of its planetary status. Articles about the
possibility generated widespread public disapproval.

The 1999 fracas was not spurred by the IAU, however, and the
international organization ultimately issued a press release stating
its regret that "incomplete or misleading" press reports on the status
of Pluto "appear to have caused widespread public concern." The
statement went on to assure that "no proposal to change the status of
Pluto as the ninth planet" had been made within the IAU.

Dual status

Many astronomers have since been content to let the IAU and the public
call Pluto a planet, while most of them think of it as a Kuiper Belt
Object, one of many frozen worlds beyond Neptune. Some fight actively
for Pluto's demotion while others think Sedna and its like should join
the cast of planets.

In the meantime, scientists still have not defined planethood and
Sedna, the strange new world, has only increased the need for sorting
out the terms of the solar system.

Sedna is about three-fourths Pluto's size and is presently about three
times as far from the Sun. It ranges much farther into space on a
long, elliptical orbit around the Sun that takes 10,000 years to
complete. It is frigid and almost surely lifeless. But it is round,
like the other planets. It's probably made of rock and ice, though
astronomers don't know its exact composition.

Several astronomers have said that if Pluto is a planet, then Sedna
should be considered a planet.

On the flip side, however, some of those same astronomers prefer the
catchall term "planetoid" for both of these round but small worlds.
Classification systems, they argue, will work themselves out only
after more objects are found and astronomers glean a better
understanding of the suddenly more mysterious outer solar system.

The accident of Pluto

For years most astronomers have said that Pluto is an accident of
observational history and should never have been called a planet.
Pluto was discovered by Tombaugh, an amateur astronomer, in 1930.

"When Pluto was given planet status, its diameter was thought to be
nearly 15,000 kilometers [9,320 miles], 12 percent larger than the
Earth," points out Williams, the IAU official. "In terms of size, it
was the fifth planet rather than the ninth."

And for decades after Pluto's discovery, no other objects were
discovered beyond Neptune. In recent years, however, other round
objects about half Pluto's size have been detected in the Kuiper Belt,
much closer than Sedna. Michael Brown, a Caltech astronomer who led
the discovery of Sedna and two other good-sized worlds, expects there
are more.

In fact, there's even the chance of an Earth-sized planet lurking out
there, he and others say.

Pluto's plight involves many factors. It is about 1,413 miles (2,274
kilometers) wide -- smaller than Earth's Moon. But most astronomers
don't see that as a disqualifying factor.

More significant, Pluto is inclined 17 degrees to the main plane of
the solar system in which the larger planets orbit. Other planets have
inclined orbits, too, but none compare to the leanings of Pluto. It's
orbital path is also very non-circular; it ranges between 30 and 50
astronomical units (AU) from the Sun. One AU is the distance from
Earth to the Sun, about 93 million miles (150 million kilometers).

Senda's travels are even stranger in one sense. It roams from 76 to
1,000 AU. Sedna's inclination is 12 degrees, less than that of Pluto.

"It blurs the line between what is a planet and what is not," said
Alan Boss, a planet-formation theorist at the Carnegie Institution in
Washington DC. It also blurs the line between the Kuiper Belt, where
Pluto resides, and the more distant Oort Cloud, a reservoir of comets
that stretches halfway to the next star.

Scientists have not known what, if anything exists in a possible void
between the two regions. But at the least there is Sedna, officially
catalogued as 2003 VB12. Now they don't know where to stick this
latest discovery. They can't even be sure where it formed, and they're
very unsure as to how it got such an odd trajectory.

"It blurs all sorts of lines," Boss said.

Embarrassing

"It's something of an embarrassment that we currently have no
definition of what a planet is," Gibor Basri of the University of
California, Berkeley, has said. "People like to classify things. We
live on a planet; it would be nice to know what that was."

Basri has previously proposed simply setting a lower diameter limit
for planet status, including all objects orbiting the Sun that are
about 435 miles (700 kilometers) wide or more. That's roughly the bulk
needed to allow gravity to shape an object into a sphere, depending on
density. Smaller objects -- both asteroids and comets -- tend to take
on odd shapes like that of a potato.

Basri's simple definition would boost the tally of planets in our
solar system to more than a dozen based on presently known objects,
including Sedna. And it would leave Pluto as a planet.

Many astronomers, though, simply don't see a solar system with more
than eight planets.

"Scientifically, there really is no question" that Pluto should be
reclassified, says Brown, the Caltech astronomer who helped find
Sedna.

"Either Pluto is not a planet, or many other things are planets,"
Brown said today. "Which is a better choice? I want my planets to be
more special, not less special, so I favor Pluto not being a planet.
Emotionally, though, I have to admit that I have grown up thinking
Pluto this special odd-ball planet at the edge of the solar system.
While I now know scientifically that Pluto is less special, it's still
hard to let go."

Tough job

Whatever the IAU working group decides, the process might stretch out
for two years before any decision is rendered, if at all.

"If it was felt that Pluto required special status, then ratification
at the next General Assembly would be called for," Williams said. That
international IAU meeting will be held in Prague in 2006.

Boss, the Carnegie theorist, is not sure the issue will be settled
even by then.

But Boss does think the IAU's efforts are necessary and worthwhile.
"It sort of sharpens peoples thinking" about how the solar system is
organized, he said. But it won't necessarily silence astronomers who
have strong feelings one way or the other.

"Whoever gets shut out will continue to argue," Boss told SPACE.com.
"I sure would not want to be on the working group myself."

"Netvigator" wrote...
in message ...

Surely it is /was not a planet!!

(1) By the classic definition (very general) Pluto is/was and
always will be... a planet.

(2) By the official stance presently taken by the IAU (the
International Astronomical Union which decides these sorts
of things) Pluto is/was and may remain for a long time to
come... a planet. However, this is a controversial side issue
to the IAU's present task of better defining the word "planet."

1) When it was found, it was used to explain the gravitational distribance
for Neptune, but it is too small. (It means the ninth planet which causes
this effect was not found, so it is why they are looking for the 10th one.)

(3) "They" are no longer looking for a tenth planet. The
anomalies in the orbit of Uranus which led to the discovery
of Neptune as well as the astronomically massive good
fortune of discovering Pluto, these anomalies are no longer
believed to warrant the existence of a tenth planet beyond
Pluto. If this ever changes again in the future, the numerous
Kuiper Belt objects (KBOs) would probably account for
any future perceived anomalies in the orbits of the outer
planets.

2) As astronomy advances, many have found the problem of this
classification, because it is clear that it is only a bigger brother of the
planetoids only.

Yes, some serious problems have arisen. There are some
very earnest scientists presently doing extensive and intensive
studies of KBOs. They are constantly confronting confusing
data collection problems due to Pluto's official classification
as a planet rather than a KBO.

3) The strongest support for Pluto as a planet is ....
tradition! really strong tradtion!

Tradition! Heaven forbid that tradition be honored. Let's
have chaos instead! g

(Don't forget it is an American who found this.)
What's a pity!
Oh! Galileo is used to prove that the Catholic church is too much dependant
on the tradition; but now it is the astronomists who called themselves
'scientists'. (Who should follow evidences, not tradition.) to emphasize the
untouchable tradition: Pluto is a planet (Though it is clear that it is due
to misunderstanding before.(

True, Pluto was first thought to be quite large in order to have
such an effect upon the planet Uranus. And it took many, many
years before science was able to show just how small Pluto
really is. In all those many, many years, the tradition of Pluto as
being a planet became indelibly engrained. There are posters on
the walls of elementary schoolrooms that depict the "nine planets,"
and they do include Pluto as the ninth.

If i were a fourth grader, i'd tear the damn things down! g

happy days and...
starry starry nights!

--
Life without love is
A lamp without oil,
Love without prejudice,
A tool without toil--
World without soil.

Paine Ellsworth

Hi Painius What if pluto with its moon was just 90 million miles from
the sun?. Would it be a good planet for some form of life(fish) Bert

Painius wrote:

Yes, some serious problems have arisen. There are some
very earnest scientists presently doing extensive and intensive
studies of KBOs. They are constantly confronting confusing
data collection problems due to Pluto's official classification
as a planet rather than a KBO.

What kind of problems? Surely the data look the same whether we call
Pluto a planet, a KBO, or, for that matter, a Bandersnatch?

--
Odysseus

..or, for that matter, a Bandersnatch?
--
Odysseus

What about a Jabberwocky? Or a Jub-jub Bird? oc

"Odysseus" wrote...
in message ...

Painius wrote:

Yes, some serious problems have arisen. There are some
very earnest scientists presently doing extensive and intensive
studies of KBOs. They are constantly confronting confusing
data collection problems due to Pluto's official classification
as a planet rather than a KBO.

What kind of problems? Surely the data look the same whether we call
Pluto a planet, a KBO, or, for that matter, a Bandersnatch?

--
Odysseus

I'm not sure as to the kinds of problems other than reading that
some scientists believe that data analysis would go much smoother
if Pluto were officially reclassified. I'll see if i can come up with
where i read this. It's been a while since i researched it. Probably
stuck in my mags somewhere like a minuscule needle in a haystack.

g

BTW -- my Webster's lists "miniscule" as a valid variation of the
word "minuscule."

happy days and...
starry starry nights!

--
Life without love is
A lamp without oil,
Love without prejudice,
A tool without toil--
World without soil.

Paine Ellsworth