[extropy-chat] Solar System Planets Definition - Petition and Grassroot efforts

[Amara Graps]

A petition (*) going around the planetary community (unfortunately
during holiday time in Europe) to protest the IAU decision is closed
now (**). It will be transmitted to the International Astronomical
Union (IAU). However, since the IAU meets only once every 3 years,
this issue won't be able to be resolved by them until 2009. In these
next years then, an effort is underway to involve many people
(scientists and nonscientists and the public) in order to resolve
whether planets should be defined based on their dynamical properties
or based on their intrinsic properties or perhaps another way.

Meanwhile more than 800 KBOs (1) have been found and that number is
increasing ....

Amara

(1) http://en.wikipedia.org/wiki/Kuiper_belt
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(*) It started out like this:


Less than 5% of the astronomical community voted at the Prague IAU for a
definition of 'planet' that uses dynamics (location) rather than
intrinsic properties to decide if an object is or is not a planet. This
result is counter to other classification schemes in astronomy (e.g.,
stars, galaxies, nebulae, even asteroids) in which dynamical context
does not play a controlling role. Furthermore, it produces results that
are incongruous and cannot be extended within our own solar system or to
extra-solar planetary systems without producing immediate results that
are patently absurd: e.g., a Neptune-sized object discovered beyond 150
AU could not be a planet, the presence of an Earth orbiting its star
between a Jupiter and a Saturn would mean the Earth could not be
considered a planet since it could not clear its "neighborhood". This
definition also excludes Pluto from planethood in our solar system,
something that is both scientifically questionable and publicly
problematic. Both Pluto and a distant Neptune would be classified as a
"dwarf planet", which is not to be considered a subcategory of "planet".


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(**) http://www.ipetitions.com/petition/planetprotest/

Petition Protesting the IAU Planet Definition

We, as planetary scientists and astronomers, do not agree with the IAU's
definition of a planet, nor will we use it. A better definition is
needed.


SIGNATURES (Final - August 30, 2006 6 AM PST) [PDF]


Sufficient signatures from planetary scientists and astronomers have
been gathered to bring into serious question the definition for planet
adopted by the IAU as fundamentally flawed, as was the process by which
it was generated.

The list of signatories have studied every planet in the solar system,
asteroids, comets, the Kuiper Belt, and planet interactions with space
environment. They have been involved in the robotic exploration of the
solar system from some of the earliest missions to Cassini/Huygens, the
missions to Mars, ongoing missions to the innermost and outermost
reaches of our solar system, and are leading missions preparing to be
launched. The list includes prominent experts in the field of planet
formation and evolution, planetary atmospheres, planetary surfaces and
interiors, and includes international prize winning researchers.

The IAU is incapable of correcting this action until its next General
Assembly in 2009. In the meantime, the IAU definition will stand as a
source of confusion and incongruity to educators and the public. An
alternative is needed.

Planning is underway to establish an open and inclusive grass-roots
process by which planetary scientists and astronomers from around the
world can approach a better resolution to the issue of planets in our
own solar system and elsewhere, with every step and discussion in public
view. This process should culminate in a conference, not to determine a
winner, but to acknowledge a consensus.

The discussion will be wide ranging and should offer the public a
fascinating and educational view of scientific discourse on a topic to
which they can all relate.

A further announcement will be made in September from the initial
sponsoring institutions.

Planetary Science Institute
Southwest Research Institute
-- 

Amara Graps, PhD      www.amara.com
Istituto di Fisica dello Spazio Interplanetario (IFSI), Roma, ITALIA
Associate Research Scientist, Planetary Science Institute (PSI), Tucson