Re: Planetary taxonomy: A diplomatic solution


Margo Schulter wrote:
George Dishman <george@xxxxxxxxxxxxxxxxx> wrote:

<snip side issue>

Anyway, that's my first take on this.

Most appreciatively,

I'm glad you found my comment on that useful and
it is god to know we agree that topic.

Pehaps as a "second take" you could address my
comments on the issue we were actually discussing,
that of whether objects in other star systems can
fall within the new IAU definition of 'planets'.
I repeat that section below for your convenience:


George Dishman wrote:
"Margo Schulter" <mschulter@xxxxxxxxxxxxxxx> wrote in message
news:44f7c69c$0$84240$d368eab@xxxxxxxxxxxxxxxxxx
....
I think that I can clarify the
second point concerning "extra-solar planets."

Actually IAU Resolution 5A restricts its domain to
classifying objects in our own solar system; the question
of defining planets elsewhere is simply left unaddressed,
and likely reserved for a future meeting (the next one in
Rio, 2009).

Well that may be the idea but the outcome has been
to produce a definition of the word "planet" that
should find its way into most good dictionaries.
The idea that an object identical to Earth but
around another star identical to the Sun might not
be a planet (but we haven't decided yet) is not
one that is going to be treated with any respect.

The actual text says this:

"Contemporary observations are changing our
understanding of planetary systems, and it
is important that our nomenclature for
objects reflect our current understanding.
This applies, in particular, to the
designation 'planets'. The word "planet"
originally described "wanderers" that were
known only as moving lights in the sky.
Recent discoveries lead us to create a new
definition, which we can make using currently
available scientific information."

Note in particular "Recent discoveries lead us to
create a new definition" for the "designation
'planets'." That is not restricted to the solar
system but states it is a definition of the word.
It goes on

"The IAU therefore resolves that planets and
other bodies in our Solar System, except
satellites, be defined into three distinct
categories in the following way:"

so there are only three categories of [bodies] and
all reside in our solar system.

There is a note saying

"An IAU process will be established to assign
borderline objects into either dwarf planet
and other categories."

but I see nothing whatsoever on the page to say
that this definition is not applicable to objects
outside the solar ystem or that it will be further
considered in 2009.

Thus the resolution doesn't directly affect the status of
any extra-solar planet, much less remove its planethood,
which is simply left officially unaddressed.

Sorry, that isn't the case according to the page
I cited. That's why I asked if this was merely
one of the drafts and the final resolution
corrected these problems. Replacing "the Sun" by
"a star" would have resolved that problem (with
perhaps a footnote regarding binary systems etc.).

We can debate whether the IAU was wise to adopt a planetary
taxonomy for objects in our own solar system only, as well as
the wisdom of its specific conclusions. However, I would
emphasize that extra-solar planets are just as much planets
as they were on August 23, the day before the resolution was
adopted.

While your interpretation may seem resonable, it
is not the resolution that was passed.

best regards
George

.

Relevant Pages

  • GALACTIC FEDERATION Update: February 1, 2005
    ... Our ships continue to monitor Mother Earth and to observe the ... energies that hold the solar system together. ... the outer planets. ... her surface will start to exhibit greater signs of coming back to life. ...
    (sci.astro)
  • Re: Soon 12 planets in the solar system !
    ... And I did talk about other other things than the current 9 planets. ... about the solar system and don´t mention Pluto. ... Who says you shall not mention Pluto? ... Reason is the minimum requirement in science. ...
    (sci.astro.amateur)
  • Re: Tom Van Flandern and Newtonian Gravity
    ... decreases, the orbit must spiral outward or inward, respectively. ... These are where stars or planets ... the angular momentum of the solar system. ... origin of the solar system's major planets and major moons with a single ...
    (sci.physics.relativity)
  • Re: How special is the Solar System? (Forwarded)
    ... Further, it is actually three stars, Beta and Proxima Centuari as well. ... Centuari solar system might function. ... must be billions of planets in this galaxy alone. ... :> Monthly Notices of the Royal Astronomical Society. ...
    (sci.space.policy)
  • Re: "Pluto Now Called a Plutoid"
    ... I think they assumed that most people reading their resolution would not be trying to lawyerly nitpick holes in it but would instead be more interested in the basic spirit it conveyed. ... unclear whether that is a dwarf planet or a small solar system body. ... The only thing being called into question as imprecise here is the distinction between dwarf planets and small solar system bodies, ...
    (rec.arts.sf.science)