PLEASE NOTE:
*
CAMBRIDGE-CONFERENCE DEBATE, 26 March 1998
------------------------------------------
During the last couple of weeks, the number of comments by list
members sent for circulation on the CCNet has considerably
increased. While I and many other list members appreciate this
demand for enlightening debates and discussions, others might not
find them of great interest or importance to them. Should you be
such a member who wishes to receive ONLY the CC DIGEST (and not
the
additional CC DEBATE), please be so kind and let me know.
Benny J Peiser
=======================
(1) NEO DEFLECTION SYSTEM FAR TOO DANGEROUS TO DEVELOP
Alan W. Harris <awharris@lithos.jpl.nasa.gov>
(2) WEST TEXAS CRUDE
Duncan Steel <dis@a011.aone.net.au>
(3) WHAT ARE THE PHYSICS & METEOROLOGY BEHIND 'JOSHUA' EVENT?
Jonathan Shanklin <jdsh@mail.nerc-bas.ac.uk>
===================
(1) NEO DEFLECTION SYSTEM FAR TOO DANGEROUS TO DEVELOP
From: Alan W. Harris <awharris@lithos.jpl.nasa.gov>
Dear Benny,
Re. the comments from George Wetherill, passed on to you by David
Morrison,
I too am skeptical if an impending collision by an asteroid could
be "a
wonderful thing." I worry that if something like 1997 XF11
had played
out where the error ellipse continued to shrink down close to the
Earth, so that we could certify that the object would pass only a
few
radii away from the Earth, but we could at the same time certify
that
there was no real chance of an impact, we would nevertheless see
the
folks who brought you Star Wars casting just a shadow of a doubt
on our
celestial mechanical predictions, and would be urging a massive
program
to deflect or destroy it "just in case." This
kind of stupidity is not
exactly my idea of "a wonderful thing, inspiring the nations
of the
Earth to work together to save the planet," that George
suggests, but I
am sure that is the kind of hype that would be used to sell the
program. I am quite sure that such arguments would prevail at a
level
of risk far below the level at which they are warrented; the only
question is, how low? I would venture a wild guess that a factor
of a
thousand is about right -- that is, if we were to live so long,
we
would fall victim to the development of such a deflection scheme
about
a thousand times more often than one would really be justified,
or
turned around the other way, the odds that we will be peddled a
deflection system when one is not rationally called for is about
1000 to
1 more likely than that the discovered object really poses enough
of a
threat to call for such action.
With regard to the remarks by Farinella, non-nuclear schemes
might be a
practical way to divert the mischief of those who would
"protect" us in
advance of proven need, if we are politically unable to keep them
from
"doing something." But if a real threatening
object were to be discovered,
I think most of the world's population would be happy to go with
the most
expedient solution rather than tinkering with solar sails and
other such
"green" options.
Cheers,
Al
====================
(2) WEST TEXAS CRUDE
From: Duncan Steel <dis@a011.aone.net.au>
Meteorite fall in West Texas story.
>An astronomer at the McDonald Observatory theorized that the
meteorite
>could have contained copper among its metallic ores,
explaining the
>greenish tint to its glow as it passed over Midland.
Why, just because church roofs are green? For high altitude
meteors the
green light often reported is, I believe, due to an atomic oxygen
transition. I do not have enough information about this
fireball to
make any further comment about the light emission.
>Monahans is about 60 miles southwest of Odessa.
...which is of course the location of the first definitely-proven
terrestrial impact crater, named for the town. It became
accepted as an
impact scar in the 1920's due to its association with meteoritic
iron.
Although Meteor (Barringer) Crater had been suggested as being an
impact
crater earlier, it took a long time for this to be accepted by
any but a few
'crazies.'
Duncan
====================
(3) WHAT ARE THE PHYSICS & METEOROLOGY BEHIND 'JOSHUA' EVENT?
From: Jonathan Shanklin <jdsh@mail.nerc-bas.ac.uk>
Perhaps someone (the writer ?) would care to explain the physics
and
meteorology that lies behind this curious paragraph:
> In the end it seems more likely that what happened is that
the
> disintegration of a large meteoroid of the Sikhote Alin
class released a
> large amount of kinetic energy into the atmosphere
("stones") ; this
> heated air came into contact with particles at the super
cold
> temperature of space, producing hail
("hailstones").
A meteorite shower will certainly release energy into the
atmosphere, but the
surface of the stones is warm due to frictional heating.
Most breakups also
occur at high altitude where there is insufficient water vapour
to produce
clouds never mind hail. A major impact could possibly generate
enough
convection in the lower atmosphere to create thunderstorm
activity, but why not
use Occam's razor?
Jon Shanklin
j.shanklin@bas.ac.uk
British Antarctic Survey, Cambridge, England
http://www.nbs.ac.uk/public/icd/jds
*
CAMBRIDGE-CONFERENCE DIGEST, 26 March 1998
------------------------------------------
"But if a true comet should appear in the heaven itself or
an earthquake should ensure, then it would be time for us
astronomers along with the politicians to sharpen our
pens."
(Johannes Kepler, prognostic calendar for 1618)
(1) WHY I BELIEVE NASA WAS WRONG TO JUMP THE QUEUE
Benny J Peiser <b.j.peiser@livjm.ac.uk>
(2) THE TRUTH ABOUTH THE SMOKING ASTEROID
Paolo Farinella <paolof@keplero.dm.unipi.it>
(3) PLANETARY SOCIETY HONORS GENE SHOEMAKER
Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
(4) NEXT TIME YOU SEE AN ASTEROID, WHY NOT TRY IMPROVED SOFTWARE
TO FIND OUT ITS DESTINY?
Andrea Milani Comparetti <milani@copernico.dm.unipi.it>
(5) IMPACT RATE ON MOON: 815 LUNAR IMPACTS IN 3 YEARS INCLUDING
THREE REALLY BIG ONES
Peter Grego <PeterGrego@compuserve.com>
=================================
(1) WHY I BELIEVE NASA WAS WRONG TO JUMP THE QUEUE
Benny J Peiser <b.j.peiser@livjm.ac.uk>
One of the most unfortunate actions taken during the 1997 XF11
events
two weeks ago was the hasty, and may I dare say rather
ill-considered
decision by NASA to jump the queue and not to let the IAU release
Eleanor Helin's 1990 observational data of asteroid 1997 XF11 to
the
press. While this rash move was successful in reassuring a rather
asteroid-shoked public, it inevitably created the impression of
divisions and disagreement - if not incompetence - within the
astronomical community. Obviously, a more considered and
co-ordinated
press release by NASA & the IAU could have prevented this
damaging
imprint.
It was just a question of time that parts of the media would
start
exploiting this apparent mis-management in order to further
cement the
false impression of disunity or even cover-up when in fact there
was
general agreement among all NEO researchers involved. The
following
column by FLORIDA TODAY's Billy Cox demonstrates just how
damaging the
result of this particular mis-handling has been.
There are quite a number of important lessons to learn from these
events and about how to handle a similar situation in the future.
I
hope that this debate and re-assessment will take place sooner
rather
than later.
Benny J Peiser
=========================
(2) THE TRUTH ABOUTH THE SMOKING ASTEROID
From: Paolo Farinella <paolof@keplero.dm.unipi.it>
Dear colleagues, have you seen this? It's amusing but...
------
March 20, 1998
THE TRUTH BEHIND THE SMOKING ASTEROID
By Billy Cox
A FLORIDA TODAY column
CAPE CANAVERAL, Fla. - You can smell it in the air - the special
prosecutor's office is getting close to a done deal.
Investigators are
now awaiting DNA tests from Mary Kay Letourneau's zygote that
could
provide smoking-gun linkage to the Oval Office. Negative results
will
lead to impeachment proceedings on the grounds that a 14-year-old
boy
was corrupted into licentious acts from watching the president
issue
embarrassing sex-scandal denials on TV night after night.
But with the chief executive insulated by his
It's-The-Economy-Stupid
Teflon, investigators are hot to trot on their most productive
lead
yet. It surfaced last week. Here's our Asteroid Recap For Idiots:
Wednesday afternoon, March 11. The prestigious International
Astronomical Union issued a stunning news bulletin. A mile-wide
asteroid called 1997 XF11 was set to streak between here and the
moon
on Oct. 26, 2028. Projected trajectory: 30,000 miles from Earth.
But
the calculations were skewed by a 180,000-mile margin of error.
Murphy's Law, etc., etc.
Jack G. Hills, asteroid expert at Los Alamos National Lab:
"It scares
me. It really does. An object this big hitting the Earth has the
potential of killing many, many people."
It looked like Dinosaurville for Homo sapiens. Ancient squabbling
cultures united in the choking fallout of a common destiny. The
privileged and the powerful eating dirt with peons and winos.
Earthlings hadn't been bonded by this kind of leveling euphoria
since
Apollo 11.
The engines of the entertainment economy were the first to
throttle up.
"Armageddon" producers, anticipating a
summer-blockbuster windfall from
their Hollywood asteroid, began reworking final edits around the
News
Peg From Heaven. "Deep Impact" promoters were caught
flat-footed -
their storyline hinged on a comet strike, not an asteroid. But
screening surveys indicated the distinctions were irrelevant, and
"Deep
Impact's" box-office prospects looked solid.
On Capitol Hill, legislators and defense contractors were
high-fiving
and chicken-dancin' in the bathrooms over space-shield R&D.
They
stripped down to their Speedos and prepared to dunk each other in
a
30-year supply of pork-barrel grease, their ritual mating cries
echoing
like magpies' laughter down the corridors of power - "Jobs!
Jobs!
Jobs!"
Not even during the Reagan heyday did consumers have any
confidence in
SDI's ability to protect the West from incoming fireballs.
Consumers
celebrated 1997 FX11 for different reasons. Liposuction and
high-fiber
diets seemed immaterial; cleaning the environment for future
generations, ridiculous. Within hours, Detroit reported a run on
gas-guzzlers. Big Three execs scheduled summit talks to abolish
catalytic converters.
Switchboards at seminary schools were jammed with queries about
growth
opportunities; publishing houses were jarred by resupply orders
on
religious tracts. FX11 had something for everyone. When the NYSE
closed
that afternoon, liquor futures were percolating at New Year's Eve
levels. Supermarket retailers reported junk-food shortages.
Property
values in Montana and Idaho jumped 7 1/2 percent by sunset.
In short, FX11 was triggering an economic boom that was about to
make
Wall Street's raging bulls of the mid-'90s look like manatees in
the
Sahara. And then, a funny thing happened. On March 12, FX11
changed
course.
Astronomers at NASA's Jet Propulsion Lab reported that - ahem -
the IAU
boys were a little too optimistic. JPL released new data showing
the
asteroid wouldn't hit Earth after all - the thing was going to
miss by
whopping 600,000 miles.
And just like that, the story was over. Or so it seemed.
This week, a source close to the investigation revealed that
grand jury
subpoenas have been issued to high-level IAU officials. The
Whitewater
prosecutor is apparently investigating the political makeup and
funding
sources of the IAU, which made its announcement just days before
Kathleen Willey aired her shocking "60 Minutes"
testimony. If, as the
independent counsel suspects, the IAU knowingly disseminated
false and
diversionary information in order to manipulate the economy and -
by
extension - the president's ratings, criminal indictments are
inevitable. Note: The preceding material may or may not be
accurate.
Either way, this corner welcomes the opportunity to go on
national TV
and chit-chat.
Billy Cox's column runs every Friday. He can be reached at
242-3774, or
FLORIDA TODAY, P.O. Box 419000, Melbourne, FL 32941-9000.
(c) 1998 Forida Today
=====================
(3) PLANETARY SOCIETY HONORS GENE SHOEMAKER
From: Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
Planetary Society Honors Eugene Shoemaker with Comet and Asteroid
Discovery
Grant Program Named for Astronomer Shoemaker Supports Searches
for
Potentially Dangerous Near-Earth Objects
One year ago today, this web site announced that the Planetary
Society
had launched its Near-Earth Object (NEO) Grant Program to help
discover
the comets and asteroids known to be in our planet's celestial
vicinity. Since then, this ongoing program has been dubbed the
Gene
Shoemaker Near-Earth Object Grants -- to honor the late comet and
asteroid discoverer -- and the program has given $35,000 to
researchers
from around the world who search for asteroids and comets with
orbits
close enough to Earth to pose a potential hazard to our planet.
The first four recipients of the grants are now putting their
grants to
work in NEO detection efforts in the United States, Russia, and
Australia.
In the US, Walter Wild in Chicago, Illinois, and Bill Holiday in
Corpus
Christi, Texas lead searches that involve amateur astronomers.
Wild, an
astronomer at the University of Chicago, leads a group of amateur
astronomers who are conducting a NEO search from Yerkes
Observatory in
Wisconsin. Amateur astronomer Holiday is using his grant to
upgrade his
home-built rotating roof observatory.
Kirill Zamarashkin is the project coordinator for a joint
Russian-Ukrainian search program at the Crimean Astrophysical
Observatory. This research team has used its Gene Shoemaker grant
money
to help construct the first element of an automatic complex to
search
for NEOs.
Based in Loomberah, New South Wales in Australia, Gordon Garradd
is
using his Gene Shoemaker NEO Grant to complete a 45-centimeter
(18-inch) Newtonian telescope and to acquire a larger,
higher-grade
imaging sensor (a CCD, or charge coupled device).
A recent report of Earth's impending close encounter with an
asteroid
(featured in an earlier headline article on this web site)
emphasized
the importance of detecting the comets and asteroids whose orbits
might
intersect Earth's. Astronomers estimate that there are several
thousand
NEOs larger than one kilometer and 150,000 to perhaps 100 million
larger than 100 meters in size.
While various astronomical groups and NASA advisory committees
have
made strong recommendations to accelerate discovery of these
asteroids,
government support for NEO search programs remains very modest.
Thus,
the Planetary Society's Gene Shoemaker Near-Earth Object Grants
help
fill this funding gap.
The Planetary Society launched its Near-Earth Object Grant
Program to
increase the rate of discovery and to permit wider participation
by
amateur observers; observers in developing countries; and
professional
astronomers who, with seed funding, could greatly increase the
potential of their programs to contribute significantly to the
search.
The Society accepts applications for these grants continuously.
To apply for a Gene Shoemaker Near-Earth Object Grant, read the
guidelines and fill out the application form, which are provided
on
this web site:
http://planetary.org/NEO/neo-guidelines.html
========================
(4) NEXT TIME YOU SEE AN ASTEROID, WHY NOT TRY IMPROVED SOFTWARE
TO FIND OUT ITS DESTINY?
From: Andrea Milani Comparetti <milani@copernico.dm.unipi.it>
I believe this announcement [attached] could be of interest for
the
people in your mailing list. Next time they could be able to
compute
the closets approach by themselves, rather than believeing what
the
media say.
Andrea Milani
Dipartimento di Matematica
Via Buonarroti 2
56127 PISA ITALY
tel. +39-50-844254 fax +39-50-844224
E-mail: milani@dm.unipi.it
WWW: http://adams.dm.unipi.it/~milani
Dear OrbFitters and dear friends,
This message announces a new and significantly improved
distribution of
the public domain software OrbFit.
The software can be obtained at
ftp://copernico.dm.unipi.it/pub/orbfit
This software system has been developed by a consortium including
the
groups led by A. Milani (Pisa University), M. Carpino
(Astronomical
Observatory Milano/Brera), K. Muinonen (Helsinki Univesrity) and
Z.
Knezevic (Astronomical Observatory Belgrade). The purpose is to
make
available to observers of asteroids (and comets) an easy to use
but
accurate and reliable software to compute preliminary orbits,
ephemerides, improved orbits (by differential corrections),
identifications, and other auxiliary functions, to allow the
processing
of astrometric observations and the planning of observational
campaigns
(typically to recover lost objects).
The main improvements in the current version 1.6.0, with respect
to
the previous 1.5.1, include:
1) capability to input automatically orbital elements in widely
used
formats, such as MPC-Asteroids and Lowell Observatory astorb.dat;
these
formats are auto-detected.
2) increased reliability and portability, due to tests performed
with 6
different compilers, one syntactic checker, and 3 different
versions of
JPL ephemerides. Also to more structured software and safer
programming
practices (e.g. IMPLICIT NONE).
3) DOS version, which can run on low cost PC (the disribution
includes
exectutables, no need for compilers).
4) revised Everhart propagator (support by G. Valsecchi is
acknowledged).
5) unified standards, file formats and control logic between the
two
main programs ORBFIT (batch mode) and FITOBS (menu driven
interactive).
Now also FITOBS includes the Gauss preliminary orbit
determination.
Although the software has been deeply changed, the new version
has gone
back to the 'look and feel' of the original OrbFit1.0 (that is,
the
software written by Karri Muinonen), e.g. in the possibility for
the
user to perform both manual and automated transformations to the
'residuals and weights' files (RUNNAME.orw and RUNNAME.frw for
ORBFIT
and FITOBS respectively). This allows fine tuning of the orbital
fit,
suitable for the professional user, as well as automatic
operations
suitable also for the less experienced users. Thus the orbit
determination and improvement task is quite complete.
The main limitations remaining are:
1) although some progress has been done on the online hypertext
user
manual, still it is only a skeleton, and we have to write much
more to
make it really informative, especially for the novice user.
2) the observation planning task is very incomplete, and new
functions
have to be added.
3) the identification task is incomplete, pending verification of
the
performance of the new algorithms, which will be included in the
distribution only when reliably tested.
For the future releases we shall be working on these three
points, plus
on an online help system, a WINDOWS95 version, and additional
preliminary orbit capability.
Copyright (C) 1997 Andrea Milani, Mario Carpino, Karri Muinonen,
Zoran Knezevic
This program is free software; you can
redistribute it and/or modify
it under the terms of the GNU General Public
License as published by
the Free Software Foundation; either version 2
of the License, or
(at your option) any later version.
This program is distributed in the hope that
it will be useful,
but WITHOUT ANY WARRANTY; without even the
implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU
General Public License
along with this program; if not, write to the
Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA
To contact us:
milani@dm.unipi.it
carpino@brera.mi.astro.it,
karri@gstar.helsinki.fi,
zoran@aob.bg.ac.yu,
========================
(5) IMPACT RATE ON MOON: 815 LUNAR IMPACTS IN 3 YEARS INCLUDING
THREE REALLY BIG ONES
From: Peter Grego, Lunar Section Director, Society for Popular
Astronomy <PeterGrego@compuserve.com>
Dear Dr Peiser
In reply to, and to expand on impact matters lunar....
1. A 12th Century Minor Asteroid Impact on the Moon's far-side?
The supposed AD 1100 lunar impact mentioned by Simon Jeffery and
David
Morrison I think refers to a remarkable event in AD 1178
chronicled by
Gervase, a 12th century monk whose chronicle is preserved in the
library of
Trinity College, Cambridge. On 18 June (old calendar) in the year
1178, a
group of men at Canterbury in England were admiring the beautiful
four-day-old crescent Moon on that warm summer's evening, Gervase
reports
them to have been startled by "a flaming torch" which
suddenly appeared at
the lunar limb, "spewing out, over a considerable distance,
fire, hot coals
and sparks." The Moon is said to have "writhed like a
wounded snake" and
assumed a blackish appearance shortly after this unprecedented
occurrence.
It is now thought by some that the 1178 event was caused by a
sizeable
meteoritic impact upon the lunar surface. As such, it was the
first of only
two major cosmic impacts to have been observed this millennium -
the
other one happened in July 1994 with the impacts of comet
Shoemaker-Levy's fragmented nucleus in the atmosphere of Jupiter.
It
is ironic that both the 1178 and 1994 events were situated just
past the
limb of the impacted object, making it impossible to directly
observe the
site of the impacts at the moment they occurred.
From the rough position of the "flaming torch"
described in the chronicle,
Jack Hartung of New York University in the 1970s worked out that
the impact
site lay at around 45 north and 90 east. Looking at
photographs taken by
spacecraft in lunar orbit, the site became seemingly obvious - a
bright,
fresh-looking 20 km diameter crater called Giordano Bruno,
situated just
past the lunar limb (36 N, 103 E) and surrounded by a prominent
system of
rays. Some of these rays actually extend past the mean limb
around onto the
near-side, so they are theoretically visible through binoculars
and
telescopes. Bruno and its rays may represent the newest major
topographical
features on any body in the solar system which are likely to be
permanent.
I have tried looking for Bruno's rays - binoculars are best
suited to this
task. Indeed, on viewing with a good lunar libration and phase
there is
some limb brightening on the northeast edge of the Moon, and some
faint
streaks on the dark Mare Crisium that may actually represent the
Bruno
ejecta system.
2. Lunar Impacts
High temperatures are formed at the lunar surface when
fast-moving objects
impact with the Moon, converting kinetic energy to heat. Some of
the
short-lived flashes which have been telescopically observed
through the
centuries are likely to have been caused by small meteoroidal
impacts.
Material thrown up by the impact would form into an expanding
shell of dust
and rock which may be visible, especially if the focus of impact
happens to
lie just beyond the terminator and the column of ejecta climbs
high enough
to be illuminated by the sun. However it has not been proven that
any TLP
flash site has ever yielded a new crater which has been detected
from the
Earth.
The most credible telescopic observation of a lunar impact seems
to have
been that of the 501 kg spaceprobe Luna 5 on 12 May 1965 as it
smashed into
Mare Vaporum (31S 8E). According to Keneth Gatland (in Robot
Explorers,
Blandford: 1972) a temporary (10 minute) cloud of "lunar
dust" measuring
225 x 80km was reported by astronomers at the German observatory
at
Rodeswich. The resultant crater is too tiny to be resolved with
Earthbound
instruments.
3. Moon impactors detected by Apollo seismometers
The four Apollo lunar seismometers detected tremors in the Moon's
crust.
Some of the vibrations recorded were due to deep moonquakes, but
many were
likely to have been caused by the impact of meteoroids on the
Moon's
surface. It was possible to estimate roughly where each meteoroid
had
landed and the force of impact. In a 2.5 year period commencing
in 1973,
most of the 815 recorded meteoroid impacts were randomly
distributed. But
on three occasions - November and December 1974 and June 1975 -
the Moon
seems to have ploughed through a dense barrage of large
meteoroids.
Peter Grego
Lunar Section Director, Britain's Society for Popular Astronomy
PeterGrego@compuserve.com
--------------------------------
THE CAMBRIDGE-CONFERENCE NETWORK
--------------------------------
The Cambridge-Conference List is a scholarly electronic network
moderated by Benny J Peiser at Liverpool John Moores University,
United Kingdom. It is the aim of this network to disseminate
information and research findings related to i) geological and
historical neo-catastrophism, ii) NEO research and the hazards to
civilisation due to comets, asteroids and meteor streams, and
iii) the
development of a planetary civilisation capable of protecting
itself
against cosmic disasters. To subscribe, please contact Benny J
Peiser
b.j.peiser@livjm.ac.uk
. Information circulated on this network is
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may
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