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International Astronomical UnionCommission 4 : Ephemerides Newsletter Nr. 6 |
International Astronomical UnionCommission 4 : Ephemerides Newsletter Nr. 6 |
October 14, 1998
Subject: Newsletter No. 7
International Astronomical Union
Commission 4: Ephemerides
Newsletter No. 7 October 13, 1998
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President Vice President
E Myles Standish Jr Jean Chapront
301-150 Bureau des Longitudes
Jet Propulsion Laboratory 77, avenue Denfert Rochereau
Pasadena, CA 91109 USA F-75014 Paris, FRANCE
Tel: 1 818 354 3959 Tel: 33
Fax: 1 818 393 6388 Fax:
ems@smyles.jpl.nasa.gov jean.chapront@bdl.fr
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7.0 Contents of this Newsletter
7.1 Introduction : the Minor Planet Center's Intention of Assigning
a Minor Planet Number to Pluto.
7.2 Letter from Professor Richard Binzel, MIT
7.3 Letter from Kaare Aksnes, President of IAU Working Group
for Planetary System Nomenclature
7.4 Poll of the IAU Commission 4 Membership
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7.1 Introduction
The two letters which follow show that the Minor Planet Center has the
intention of assigning a minor planet number to the planet Pluto. The
letters also give the opinions that such an action, in the eyes of the
public, would have the effect of reclassifying Pluto from a major to a
minor planet.
It is strongly felt that before such an action is taken, the whole idea
should be discussed by the IAU and by the astronomical community as a
whole, and further, that members should have the chance to voice their
opinions.
As a possible solution, there is a suggestion to introduce a new Kuiper
Belt Object catalog in which Pluto would be the leading object, K/1,
sort of a "progenitor", without altering its status as a planet.
I enclose a short poll to solicit opinions from our Commission. The poll
is given in Section 7.4. Please let me know your opinions so that I may
forward them to Drs. Binzel and Aksnes.
Myles Standish
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7.2 Letter from Professor Richard Binzel, MIT
DATE: 1998 October 8
MEMO TO:
IAU President: Robert P. Kraft
IAU General Secretary: Johannes Andersen
IAU Assistant General Secretary: Hans Rickman
IAU President-Elect: Franco Pacini
Commission 4 President: E Myles StandishJJ
Commission 6 President: Richard M West
Commission 15 President: Vincenzo ZappalaJ
Commission 16 President: Catherine de Bergh
Commission 16 Vice-President: Dale P Cruikshank
Commission 20 President: Hans Rickman
Commission 20 Vice-President: Edward L G Bowell
Commission 41 President: Steven J DickJ
Working Group for Planetary System Nomenclature: Kaare Aksnes
cc: Brian G Marsden
FROM: Richard P. Binzel
Associate Professor of Planetary Science
and MacVicar Faculty Fellow
Massachusetts Institute of Technology
SUBJECT: Assignment of a Minor Planet Number to Pluto
Dear Colleagues,
The IAU Minor Planet Center is on the verge of assigning a minor
planet number to Pluto, as learned through public statements(1,2)
and direct discussion with Brian G. Marsden.
The purpose of this memo is to call your attention to this matter
and to ask each of you to perform two actions:
(1) Consider whether it is appropriate or desirable to have
discussion and consensus within your Commission, Working
Group, or the General Assembly on the matter of assigning
a minor planet number to Pluto _prior_ to such an action
being taken by the Minor Planet Center.
(2) Make your view known to the Minor Planet Center and
your fellow IAU Officers regarding the need for discussion
and consensus prior to any action resulting in the
assignment of a minor planet number to Pluto.
It is my opinion that in the eyes of the world, the action by the
IAU Minor Planet Center of assigning a minor planet number to Pluto is
tantamount to an official IAU declaration that Pluto be "reclassified"
from its status as a "planet" to a new status as a "minor planet."
Although such a perception may or may not be an intended consequence of
the assignment of a minor planet number to Pluto, it is an incumbent
responsibility of the Minor Planet Center and the broader IAU
community to fully consider and discuss the historic and public
consequences of such an action _prior_ to its being undertaken.
More fundamentally, I believe the matter of addressing a new description
of the structure of our solar system, in light of the discovery of the
the Kuiper Belt, merits full discussion and consensus within a broad cross
section of IAU Commissions and perhaps the General Assembly. Action
at this time by the Minor Planet Center to assign a minor planet number
to Pluto *pre-empts* the necessary discussion that should occur during the
time of the next General Assembly.
Sincerely,
Richard P. Binzel
Associate Professor of Planetary Science
and MacVicar Faculty Fellow
Massachusetts Institute of Technology
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7.3 Letter from Kaare Aksnes, President of IAU Working Group
for Planetary System Nomenclature
Date: 12 October 1998
Memo to:
IAU President Robert P. Kraft
IAU General Secretary Johannes Andersen
IAU Assistant General Secretary and
Commission 20 President Hans Rickman
IAU President-Elect Franco Pacini
IAU Minor Planet Center Director Brian G. Marsden
Commission 4 President E. Myles Standish
Commission 6 President Richard M. West
Commission 15 President Vincenzo Zappala
Commission 16 President Catherine de Bergh
Commission 20 Vice-President Edward L. G. Bowell
Commission 41 President Steven J. Dick
Professor Richard P. Binzel
From: Kaare Aksnes
President of IAU Working Group
for Planetary System Nomenclature
Subject: Assignment of a Minor Planet Number to Pluto
Dear Colleagues,
With reference to Richard Binzel's memo of 8 October, I fully
support his initiative in urging consultation of the entire
astronomical community before deciding whether or not to
assign a minor planet number to Pluto. As professor Binzel
writes, such an assignment is tantamount to downgrading Pluto
from a major to a minor planet, in the eyes of most people.
I am on the record, in the Atlantic Monthly issue of February
1998 and elsewhere, as an opponent of changing Pluto's status
in any way. I accept that if Pluto were discovered today, it
would probably have been classified as a minor planet, although
Pluto is more than twice as big as minor planet No. 1, Ceres,
and does possess a moon. However, Pluto was discovered 68 years
ago; and despite its small size, Pluto is a very special planet
with an intriguing history which precedes its discovery, since
Clyde Tombaugh started his search for it based on predictions --
albeit fortuitous -- many years earlier by Percival Lowell.
This historical record and precedence for full planet status
outweigh the recent physical evidence against, in my opinion.
A few years ago, the IAU Working Group for Planetary System
Nomenclature (WGPSN) discussed Pluto's status in response to
an initiative by several astronomers to reclassify Pluto as a
minor planet. The WGPSN members then voted unanimously against
such a reclassification. Brian Marsden, director of the IAU
Minor Planet Center and also a member of WGPSN, claims that
assignment of a minor planet number does not necessarily remove
its status as a major planet. I am personally against allowing
such a dual classification of Pluto, but I see a need for
WGPSN to discuss this.
Consequently, this Pluto question has been put on the agenda
for the next WGPSN meeting, which will be held in Paris
October 26-27, 1998. After that meeting, I will report back
to you about WGPSN's stand on this issue.
Sincerely yours,
Kaare Aksnes
References:
(1) Atlantic Monthly, February 1998, page 33.
(2) "Quirks and Quarks" April 11, 1998. Canadian Broadcasting Corporation.
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7.4 Poll of the IAU Commission 4 Membership : the Minor Planet Center's
Intention of Assigning a Minor Planet Number to Pluto.
Please give your opinion to the following 4 statements (strongly agree/
somewhat agree/no preference/somewhat disagree/strongly disagree) :
1) Assign a minor planet number to Pluto.
2) Introduce a new Kuiper Belt Object catalog in which Pluto would be the
leading object.
3) The question of assigning a minor planet should be discussed by the
IAU prior to any action being taken.
4) The question of assigning a minor planet should be discussed by the
astronomical community at large prior to any action being taken.
Please include any comments that you would like to have made known.
[ Please return the poll to me ]
Myles Standish
President, IAU Commission 4
E Myles Standish Jr
301-150
Jet Propulsion Laboratory
Pasadena, CA 91109 USA
ems@smyles.jpl.nasa.gov [128.149.23.23]
JPL 301-150; Pasadena, CA 91109
TEL: 818-354-3959; FAX: 818-393-6388
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