PLEASE NOTE:
*
CCNet DIGEST, 8 February 1999
-----------------------------
QUOTE OF THE DAY (from THE ECONOMIST, 6-12 February)
"One way to resolve the issue might
be to send an unmanned space
probe to Pluto. A mission to Pluto could
establish whether it is
merely the biggest of a large family of
similar bodies, or an
interesting object in its own right.
Such a mission, the Pluto
Express, is already planned. If all goes
well, it will be launched
in 2004 and arrive at its destination
about ten years later."
(1) HOW SCHOOLCHILDREN & THEIR TEACHERS WON THE DAY:
BUT PLUTO WILL REMAIN ASTRONOMICAL HOT-POTATO
FOR YEARS TO COME
THE ECONOMIST, 6-12 February 1999
http://www.economist.co.uk/editorial/freeforall/current/index_science_and_technology.html
(2) A VOICE THAT WON'T BE HEARD (YET): TWO-THIRDS IN BELATED
EXPERT
SURVEY VOTE FOR PLUTO'S SECOND PASSPORT
Minor Planet Center
<http://cfa-www.harvard.edu/mpec/J99/J99C10.html>
(3) STARDUST SUCCESSFULLY LAUNCHED
Ron Ballke <BAALKE@kelvin.jpl.nasa.gov>
(4) LEONID OUTBURST ACTIVITY IN 1996
Casper ter Kuile <pegasoft@accu.uu.nl>
====================
(1) HOW SCHOOLCHILDREN & THEIR TEACHERS WON THE DAY:
BUT PLUTO WILL REMAIN ASTRONOMICAL HOT-POTATO
FOR YEARS TO COME
From THE ECONOMIST, 6-12 February 1999
http://www.economist.co.uk/editorial/freeforall/current/index_science_and_technology.html
PLUTO OUT IN THE COLD
Astronomers disagree about whether Pluto really is the solar
system’s
ninth planet, or just a puffed-up asteroid, or something else
entirely
IS IT correct to refer to Pluto as the most far-out planet in the
solar
system? Technically, no. Since 1979, Neptune has been the planet
furthest from the sun, and not until the afternoon of February
11th
this year will Pluto (travelling along its unusually elliptical
orbit) cross Neptune’s orbit and once again become the more
distant
object. But even then, some astronomers argue, Pluto will still
not be
the most distant planet—because, they say, Pluto is not
really a
proper planet at all.
It fails, for example, to fit into either of the two categories
occupied by the other eight major planets. The four inner
planets,
including Earth, are rocky, and the four outer planets are gas
giants.
But Pluto is made largely of ice.
Pluto is also by far the smallest planet in the solar system,
with a
diameter of only 2,260km (1,410 miles). Four planets, including
Earth,
have moons bigger than that, and Ceres, the largest asteroid, is
not
that much smaller, at 933km across.
As well as being small, Pluto is unusually light. When it was
first
discovered (in 1930), Pluto’s mass was estimated as roughly
equal to
Earth’s. Since then, however, that value has been revised
downwards
several times. The discovery of a moon, Charon, in 1978, enabled
astronomers to arrive at their current estimate of Pluto’s
mass: around
one five-hundredth of Earth’s.
Charon’s existence might be thought to be enough to qualify
Pluto as a
proper planet. But it is not, because some asteroids (bodies that
are
known officially as “minor planets”) are also orbited
by moons. And
whilst Pluto is large enough to have collapsed under its own
gravity
into a spherical shape, that, too, is not a sufficient claim to
full
planethood, or Ceres would also be a major planet. In fact, Ceres
was
initially regarded as a true planet after its discovery in 1801,
but was quickly reclassified as a new kind of object when other,
similar bodies were discovered in nearby orbits.
Pluto’s status as a major planet looks dubious for the same
reason.
Since 1992, nearly 100 other small, icy objects have been
detected in
orbits beyond—or crossing—that of Neptune. Admittedly,
none of these
icy lumps is as large as Pluto, but the same logic that resulted
in
Ceres’s reclassification as merely the largest asteroid
suggests that
Pluto could most accurately be seen as the largest of a new class
of
bodies called trans-Neptunian objects (TNOs).
Indeed, the more astronomers find out about Pluto, the less
inclined
they are to defend its “major-planet” status. To prove
the point,
Daniel Green, the editor of International Comet Quarterly, has
drawn up
a list of the exotic terms (“ice dwarf”, “interplanetary
small body”,
“icy planetesimal”) devised by astronomers reluctant to
use the word
“planet” in connection with the distant snowball.
Because Pluto’s
atmosphere appears only when it is nearest the sun and then
recondenses
on to its surface as it moves away again, it has even been
mischievously labelled a giant comet.
In any case, as more TNOs are discovered, Pluto’s position
looks
increasingly anomalous. So how can the International Astronomical
Union
(IAU), which decides on such matters, square Pluto’s
historical status
as a major planet with all the modern evidence to the contrary?
An astronomical fudge
One approach might be to say that in order to be considered a
major
planet, a body needs to be larger than a certain diameter. Choice
of a
suitably fiddled threshold (say, 1,000km) would then make Pluto,
but
not Ceres, a major planet. This proposal was recently put to the
relevant IAU committee by its chairman, Michael A’Hearn, an
astronomer
at the University of Maryland, as a way of resolving the Pluto
problem.
But, he says, it was rejected as being too arbitrary.
Another solution, that championed by Brian Marsden of the
Harvard-Smithsonian Centre for Astrophysics in Cambridge,
Massachusetts, would be to give Pluto a sort of astronomical dual
citizenship. He suggests that the catalogue of minor planets
should
include Pluto and the other TNOs (for which no catalogue
currently
exists). And since the number of objects in the catalogue is fast
approaching 10,000, he advocates making Pluto the first
five-figure
minor planet. At the same time, though, it would retain its
major-planet status, and would be regarded officially as a planet
of
both the major and the minor sort.
There is a precedent for dual classification: three icy bodies
classed
as asteroids are also listed as comets because they have shown
comet-like behaviour in the past. But this plan, too, has its
critics.
In particular, some astronomers would prefer to see an entirely
new
catalogue of TNOs created, and object to the idea that these
mysterious
bodies should be lumped in with the rest of the asteroids.
That these alternatives are being considered at all has,
meanwhile,
resulted in a vociferous response from those who regard any
change in
Pluto’s status as a demotion. In particular, the American
Astronomical
Society’s Division of Planetary Sciences has weighed in on
Pluto’s
behalf.
On February 1st it issued a statement arguing against “dual
citizenship”. This, it said, lacked any scientific or
historical
justification. According to its chairman, Donald Yeomans, “there
is no
compelling reason to give Pluto a minor-planet number except to
keep
some cataloguers happy.” Dr Yeomans suggests that
reclassifying Pluto
would confuse schoolchildren and their teachers, invalidate
textbooks,
and offend many astronomers.
One way to resolve the issue might be to send an unmanned space
probe
to Pluto. A mission to Pluto could establish whether it is merely
the
biggest of a large family of similar bodies, or an interesting
object
in its own right. Such a mission, the Pluto Express, is already
planned. If all goes well, it will be launched in 2004 and arrive
at
its destination about ten years later.
Regardless of their views on how best to classify Pluto,
astronomers
are united in their desire to find out more about it and the
other
bodies in the region beyond Neptune. And rather than making it
harder
to garner support for a Pluto mission, as some researchers fear,
the
questioning of Pluto’s status seems, if anything, to have
advanced
their cause.
With luck, as astronomers learn more about dark and distant TNOs,
the
question of how to classify Pluto will become less controversial.
But
for the time being, as a result of all the fuss, the IAU has
decided to
leave things as they are. Pluto’s status as an astronomical
hot
potato—if not as a major planet—seems assured for some
years yet.
Copyright 1999, The Economist Newspaper Ltd.
===========================
(2) A VOICE THAT WON'T BE HEARD (YET): TWO-THIRDS IN BELATED
EXPERT
SURVEY VOTE FOR PLUTO'S SECOND PASSPORT
From the Minor Planet Center
<http://cfa-www.harvard.edu/mpec/J99/J99C10.html>
M.P.E.C.
1999-C10
Issued 1999 Feb. 5, 16:49 UT
The Minor Planet Electronic Circulars contain information on
unusual
minor planets and routine data on comets. They are published on
behalf
of Commission 20 of the International Astronomical Union by the
Minor
Planet Center, Smithsonian Astrophysical Observatory, Cambridge,
MA
02138, U.S.A.
BMARSDEN@CFA.HARVARD.EDU
or GWILLIAMS@CFA.HARVARD.EDU
URL http://cfa-www.harvard.edu/iau/mpc.html
EDITORIAL NOTICE
A clarification is necessary with regard to the Editorial Notice
on
MPEC 1999-C03. As shown at the end of the Notice, this was
reprinted
from MPC 33615-33616, which had been prepared two days
earlier. The
pressure of work to prepare the monthly batch of MPCs prevented
the
preparation of a new Notice when MPEC 1999-C03 was issued.
In the mean time, as many readers will realize, a Press Release
was
issued by Johannes Andersen, the IAU General Secretary, noting
very
clearly that Pluto would in no way be "demoted", a
point made, equally
strongly, in the Minor Planet Center's Editorial Notice. The
Press
Release also clarified that the Small Bodies Names Committee had,
in
the mean time, decided not to use the number (10000) for
Pluto.
The main purpose of our Editorial Notice, also clearly stated,
was to
select an appropriate name for (10000), given that the Feb. 2
batch
of Minor Planet Circulars contains numberings through
(9999).
In this regard, other than with its decision on Pluto, the SBNC
did not
complete its charge. It expects to make an appropriate decision
on a
name for (10000) by Feb. 26, now with the help of
information received
as a result of the invitation to readers in our Editorial
Notice.
Some 24 hours now after MPEC 1999-C03 was issued, the
messages
received are 63 percent in favor of using (10000) for Pluto, 37
percent against. The in-favor fraction has fluctuated
between 58
and 68 percent, suggesting that the vote represents a genuine
international concern, not one influenced by any campaign.
Unfortunately, there have been few suggestions of alternatives,
and
no obvious candidates have yet emerged. The SBNC will
consider all
of this information in its further deliberations, and it is to be
hoped that the outcome will be a wise decision of which the IAU
can
be proud.
Although the experiment is now officially at an end, there is
obviously
still a need for appropriate alternatives to Pluto. Given
the
precedents listed in the second paragraph of MPEC 1999-C03, we
should like the name of (10000) to be on a suitably grand scale.
I
thank everyone who participated. I also apologize to any
astronomers
who feel in any way slighted by my remarks on this subject, but
it is
also very clear that the "Pluto issue" is a very
emotional one,
separate from any scientific or historical considerations.
I
particularly apologize to my good friends Johannes Andersen, IAU
Assistant General Secretary and Commission 20 President Hans
Rickman,
and Division III President Mike A'Hearn, for any confusion caused
by
the timing of yesterday's statement, and I thank them for their
support
during this trying time.
Brian G. Marsden (C) Copyright 1999
MPC M.P.E.C. 1999-C10
===========================
(3) STARDUST SUCCESSFULLY LAUNCHED
From Ron Ballke <BAALKE@kelvin.jpl.nasa.gov>
MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Stardust Mission Status
February 7, 1999
NASA's Stardust spacecraft successfully shot into a clear blue
sky atop
a Delta II rocket from Florida's Cape Canaveral Air Station at
4:04:15
p.m. EST (1:04:15 p.m. PST) today to become the first U.S.
mission
destined for a comet, and the first-ever spacecraft sent to bring
a
sample of a comet sample back to Earth.
The Stardust team reported that the spacecraft was in excellent
health
and that its power and temperature levels are normal. The
spacecraft
is in communication with NASA's Deep Space Network, and is
controlled
through the mission operations area at Lockheed Martin
Astronautics,
Denver, Colo., and monitored at NASA's Jet Propulsion Laboratory,
Pasadena, Calif., where the mission is managed.
Sixty-six seconds after liftoff, the four solid rocket motors on
the
Delta were discarded and the first stage continued to burn until
it
shut down and fell away about 4 minutes, 30 seconds into the
mission.
A few seconds later, the Delta's second stage ignited and burned
for
about 5 minutes, cutting off at 9 minutes, 55 seconds into the
mission.
Almost immediately after the second-stage ignition, the fairing
or
nose-cone enclosure around the Stardust spacecraft was
jettisoned.
After coasting for about 11 minutes, the second-stage engine
restarted
and burned for about 2 minutes. The third stage separated
from the
second stage 24 minutes, 27 seconds into the mission; the Star 37
third
stage ignited 25 minutes, 4 seconds into the mission, burning for
about
2 minutes. At 27 minutes, 19 seconds into the mission -- or
4:31:34
p.m. EST -- the Stardust spacecraft separated from the Delta's
third
stage, stopping its spinning by firing onboard thrusters.
About 4
minutes after separation, Stardust's solar arrays began to unfold
and
pointed toward the Sun. The spacecraft's signal was
successfully
acquired by the NASA Deep Space Network complex in Canberra,
Australia, 51 minutes after launch at 4:55 p.m. EST.
Stardust is on a flight path that will deliver it to Comet Wild-2
(pronounced "Vilt-2" on January 2, 2004. The
spacecraft will gather
particles flying off the nucleus of the comet. In addition,
Stardust
will attempt to gather samples from a stream of interstellar dust
that
flows through the solar system. Captured in a glass foam
called
aerogel, the comet and interstellar dust samples will be enclosed
in a
clamshell-like capsule that will be dropped off for reentry into
Earth's atmosphere in January 2006. Equipped with
parachutes, the
capsule will float to a pre-selected spot in the Utah desert,
where it
will be retrieved and its contents delivered to scientists for
detailed
analysis.
==============
(4) LEONID OUTBURST ACTIVITY IN 1996
From: Casper ter Kuile <pegasoft@accu.uu.nl>
Meteoritics & Planetary Science 34 (1999)
Meteoritical Society, 1999. Printed in USA.
Leonid outburst activity 1996: A broad structure and a first
occurrence
of a narrow peak of fainter meteors
Marco Langbroek
Author's correspondence address:
Jan Steenlaan 46, NL-2251 JH Voorschoten, the Netherlands;
e-mail address: marcolan@stad.dsl.nl
Abstract: In 1996, a broad outburst structure of bright Leonid
meteors
similar to the 1995 and the 1994 displays (Jenniskens 1996;
Langbroek
1996b) was observed. In addition, a second narrow outburst
structure of
fainter meteors, which will be reported and discussed in this
paper,
has with certainty been observed. This observation marks the
first
detection of such a narrow structure in the new series of Leonid
outbursts. It has a similar exponential activity behaviour and
similar
emphasis on fainter meteors as shown by the 1866 and 1966 Leonid
storm
structures. Similar narrow peaks have been observed in 1965 and
1969 (Jenniskens 1995, 1996).
The broad 1996 structure of bright meteors peaked at November
17.31 =B1
0.04 (l 235=B0.28 =B1 0.04 (2000.0)). The additional narrow
structure
peaked at November 17.20 =B1 0.01 (l 235=B0.172 =B1 0.007). The
occurrence of the narrow peak can best be explained as a first
modest
sign of presence of the meteoroid structure that should be
responsible
for the expected meteor storm activity of the Leonids in
1998=961999.
The appearance 0.=B0085 before the node of 55P/Tempel-Tuttle
suggests
that the expected 1998=961999 Leonid storms might peak just
before
passage through the node of the comet.
http://home.wxs.nl/~dms-web/publications/langbroek.html
http://cavern.uark.edu/meteor/
http://www.uark.edu/studorg/metsoc/
http://www.uark.edu/meteor/abst34-1.html
----------------------------------------
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----------------------------------------
The CCNet is a scholarly electronic network. To subscribe, please
contact the moderator Benny J Peiser at <b.j.peiser@livjm.ac.uk>.
Information circulated on this network is for scholarly and
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*
CCNet LETTERS, 8 February 1999
------------------------------
CCNet LETTERS is the open discussion forum of the
Cambridge-Conference
Network. Contributions to the ongoing debate about Near Earth
Objects,
the cosmic environment of our planet and how to deal with it are
very
welcome. To subscribe or unsubscribe, please contact the CCNet
moderator Benny J Peiser at b.j.peiser@livjm.ac.uk.
(1) COMPROMISE AT PLUTO?
Simon Mansfield <simon@spacer.com>
(2) PLUTO: A HISTORIC CHANCE MISSED?
Daniel Fischer <dfischer@astro.uni-bonn.de>
(3) PANSPERMIA: WHAT'S NEW
CHANDRA WICKRAMASINGHE <xdw20@dial.pipex.com>
(4) NEOs, NASA & THE UN
Simon Mansfield <simon@spacer.com>
(5) DOES THE NATIONAL SCIENCE FOUNDATION FUND NEO RESEARCH?
Michael Paine <mpaine@tpgi.com.au>
(6) NEW WEB PAGE: "DID I SEE A FIREBALL LAND?"
Lew Gramer <dedalus@latrade.com>
(7) AIS HAZARDOUS OBJECT DEFLECTION PROGRAM
Lew Gramer <dedalus@latrade.com>
(8) WHAT ABOUT MARS CROSSING ASTEROIDS?
James Oberg <JamesOberg@aol.com>
==================
(1) COMPROMISE AT PLUTO?
From Simon Mansfield <simon@spacer.com>
After following the Pluto debate I would like to suggest a
compromise
that leaves the issue open to future adjustment following Pluto
Express.
Rather than name Pluto as the 10,000 object, why not settle on
Charon
as the 10,000 object and then leave 10,001 vacant until Pluto
Express
takes a closer look at Pluto and hopefully settles the matter
once and
for all.
If Pluto is then determined to be a massive Kuiper Belt object or
other Pluto-size Kuiper objects turn up out in the Kuiper belt,
Pluto
can then become 10,000 and Charon 10,001.
I realise this opens up another debase as to whether a satellite
can
be classified as an asteorid object, but with asteroid's also
having
satellites the debate is possibly needless hair spliting. It's
well
accepted that many of the Gas Giants and even Mars have captured
asteroids as satellites, and in the future when we will hopefully
be
able to capture asteorids howselves and bring them into orbit
about a
planet, these asteroids will obviously remain as numbered
asteorids
despite their new status as a planet's satellite.
On a final note, would anyone care to discuss the problems of
finding
further big Kuiper's given that their orbits are often highly
inclined
like Pluto, and making the amount of visible sky to big to search
in
anything other than a random manner.
Simon Mansfield
Editor
SpaceDaily.com
simon@spacer.com
=============
(2) PLUTO: A HISTORIC CHANCE MISSED?
From Daniel Fischer <dfischer@astro.uni-bonn.de>
Dear Benny,
doesn't it seem that the case for "(10 000) Pluto" has
been closed too
early? In a circular issued yesterday
(http://cfa-www.harvard.edu/mpec/J99/J99C10.html).
Brian says that 2/3
of the respondents to his call has replied with "yes"!
A historic
chance has been missed...
Daniel
======================
(3) PANSPERMIA: WHAT'S NEW
From CHANDRA WICKRAMASINGHE <xdw20@dial.pipex.com>
Dear Benny:
The piece you refer to as "Aternatives to Stardust" is
based on an
article published in http://www.panspermia.org
under "What's NEW".
The URL for the article in THE TIMES should be:
http://www.sunday-times.co.uk/news/pages/tim/99/02/03/x-timfeabam01001.html?
1969333
Chandra Wickramasingh
===========================
(4) NEOs, NASA & THE UN
Simon Mansfield <simon@spacer.com>
Benny,
The following is a basic proposal that rethinks the funding
process
while bringing the UN in to the picture along with "science
aid" to
other countries.
The US is meant to pay the UN x millions each year, it could even
be
billions I don't remember directly.
Most of this is not not paid, and what is paid is often paid
directly
to particular UN agencies that Congress feels it has more
influence
over in stopping wastage.
Whatever one's opinion of this, it is the current siutation and
will
most likely continue for some time.
SpaceGuard by its very nature needs to be an international effort
with
as many eyes to the sky as possible. In addition, the new image
comparision technology being brought to bear, requires lots of
computing power.
For the "eyes to the sky" aspect of SpaceGuard, the US,
EU and Japan
could begin directly funding a UN agency charged with managing
and
coordinating SpaceGuard. To give added value to the program,
smaller
nations with only limited resources could be brought into the
program
via direct funding from this agency. The program would then
entail
substantial science and technology training benefiting these
nations in
the here and now.
For the computing power, the US could offer a tax incentive to
major
computer companies to sponsor the program via services in kind -
either
timeshare or donation of complete systems - or a mixture of both.
In tandem, NASA should focus it's resources on developing new NEO
technology - both in the area of image processing and other
software
support, along with space science such as NEAR, StarDust etc. All
of
which in turn will be transfered to the public domain, and
hopefully
aiding in our efforts to control a trillion ton of rock moving at
15
miles a second.
Regards,
Simon Mansfield
Publisher
SpaceDaily.Com
=============================
(5) DOES THE NATIONAL SCIENCE FOUNDATION FUND NEO RESEARCH?
From Michael Paine <mpaine@tpgi.com.au>
Dear Benny,
I have perused the budget proposal of another US organisation -
the
National Science Foundation. The Geosciences section
http://www.nsf.gov/bfa/bud/fy2000/00GEO.htm
contains an interesting sentence:
"GEO-supported research also advances our ability to predict
natural
phenomena of economic and human significance, such as climate
changes,
weather, earthquakes, fish-stock fluctuations, and disruptive
events in
the solar-terrestrial environment."
I presume that asteroid/comet impacts are included in that last
odd
phrase! Like NASA there is no specific mention of funding a
search for
NEOs but we can always hope :)
Michael Paine
=====================
(6) NEW WEB PAGE: "DID I SEE A FIREBALL LAND?"
From Lew Gramer <dedalus@latrade.com>
To answer the frequent question of whether or not a witness has
actually seen a fireball land on the ground near them, I've added
a new
page to the 'meteorobs' Web Archive and Informational site. Check
it
out at:
http://www.tiac.net/users/lewkaren/meteorobs/fireballs.html
Corrections, references, and suggestions welcome!
Clear skies,
Lew
================
(7) AIS HAZARDOUS OBJECT DEFLECTION PROGRAM
From Lew Gramer <dedalus@latrade.com>
Thanks for forwarding the plea for assistance from this AIS
group, -
it seems like quite an innovative project! Here is some
additional
information.
Lew Gramer
------- Forwarded Message
From: stephanie wordsworth <wordsworth@treks.burlington.k12.ia.us>
To: Lew Gramer <dedalus@latrade.com>
Subject: Re: AIS project
Mr. Lew Gramer-
Thank you for replying to our message, it is appreciated greatly.
Due
to time availability, our program is going to be changed
slightly.
Instead of entering data and calculations being made to decide
whether
to deflect or destroy, we are only going to do deflection.
What we
need is equations, for velocity of the interceptor, the angle
that the
asteroid should be hit to insure that the angle that the asteroid
goes
off at is a safe distance from the Earth, how much time is
available to
deflect the asteroid, how much force is needed, and such. . . We
then
want to find a way to take the code from Wire Man and put that
into
Fortran so we can model the action. But, the things that we
need most
are equations. Could you pass that along? I don't know if I
told you
the name of our class or not, but it is AIS (Adventures in
Supercomputing.) What we had to do is pick a project and
come up with a program for that project.
Again, thank you for your time.
Stephanie Wordsworth
Burlington, Iowa
===========
(8) WHAT ABOUT MARS CROSSING ASTEROIDS?
From James Oberg <JamesOberg@aol.com>
Re: WHAT ABOUT MARS CROSSING ASTEROIDS?
From Jens Kieffer-Olsen <dstdba@post4.tele.dk>
In my 1982 book "Mission To Mars" I predicted that the
meteor flux
would be much higher at Mars than at Earth and that meteor
showers and
even storms would be frequently seen at night. The atmosphere is
a nice
meteor-maker. I wonder what a time exposure of the sky from some
future
lander probe would show. I wonder if an orbiter would see
anything on
the 'dark side' if it could track one region for an extended
exposure?
==================
CCNet LETTERS are an open discussion forum of the
Cambridge-Conference
Network. Contributions to the ongoing debate about our cosmic
environment and how to deal with it are very welcome. To
subscribe or
unsubscribe, please contact the CCNet moderator Benny J Peiser at
b.j.peiser@livjm.ac.uk