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(meteorobs) Excerpts from "CCNet 46/2001 - 23 March 2001"
Dr. Napier has two interesting items in this issue... I could not
avoid putting in these two, rare gloom-and-doom articles from the
gloom-laden CCNet list, as they are both unequivocally related to
meteors. I have one question: what exactly are these four 100+ km
wide comet nuclei that Dr. Napier mentions have been discovered?
I suspect he's refering to the largest Kuiper Belt Objects so far
discovered... ? If that were the case, it seems Dr. Napier would
have to rely on a "Nemesis" or some passing star, to force one of
these huge cometary objects into the inner solar system?
Well, at any rate, the models of time variation in Interplanetary
Dust developed by Napier seem of some real interest. (By the way,
the abstract given doesn't mention what considerations were taken
for either planetary perturbation or cloud self-gravitation... ?)
Clear skies,
Lew Gramer
------- Forwarded Message
From: Peiser Benny <B.J.Peiser@livjm.acdot uk>
To: cambridge-conference <cambridge-conference@livjm.acdot uk>
Subject: CCNet, 23 March 2001
Date: Fri, 23 Mar 2001 10:19:03 -0000
CCNet 46/2001 - 23 March 2001
-----------------------------
(1) STING IN THE TAIL: WITHOUT EVEN HITTING EARTH, A COMET
COULD BE AS LEATHAL [sic] AS AN ASTEROID
New Scientist, 24 March 2001
(2) TEMPORAL VARIATION OF THE ZODIACAL DUST CLOUD
W.M. Napier, Armagh Observatory
[...]
(4) MIR FALLS TO EARTH SAFELY, AS PLANNED
http://news.bbc.codot uk/hi/english/sci/tech/newsid_1236000/1236899.stm
[...]
(9) GIORDANO BRUNO CRATER
Paul Withers <withers@LPL.Arizonadot edu>
[...]
(12) METEOROIDS AND ELECRTOMAGNETIC PULSE
Luigi Foschini <foschini@tesre.bo.cnrdot it>
(13) METEOR FIREBALLS AND ELECTROMAGNETIC PULSE
Colin Keay <phcslk@cc.newcastledot edu.au>
[...]
(16) AND FINALLY: SHOCK, HORROR, AS NASA DECLINES TO
PAY PARKING FEE FOR LANDING ON EROS
Orbital Development <gnemitz@orbdev.com>
==================================================================
(1) STING IN THE TAIL: WITHOUT EVEN HITTING EARTH, A COMET
COULD BE AS LEATHAL AS AN ASTEROID
>From New Scientist, 24 March 2001
http://www.newscientist.com/newsletter/news.jsp?id=ns228351
AS GOVERNMENTS around the world prepare to spend millions studying the
threat of nearby asteroids hitting the Earth, an astronomer in Northern
Ireland is warning that comets might pose a greater danger. "We may be
looking for a swarm of bees while standing on a railway line with the train
coming," says Bill Napier of the Armagh Observatory.
Icy comets with their tails of gas and dust are much rarer than rocky
asteroids, but they don't even have to hit the Earth to do damage. A giant
comet evaporating under the Sun's glare would release billions of tonnes of
dust into the path of the Earth, Napier has shown in a new study. If this
dust rains down on Earth, it could blot out the Sun and trigger a new ice
age.
Astronomers already know of four objects they believe are giant comets
hundreds of kilometres across. And there may be as many as 2000 more lurking
in the Oort Cloud far beyond Pluto. Such comets visit the inner Solar System
so rarely that the risk of an impact is negligible. But Napier calculates
that they could release millions of tonnes of dust into our atmosphere,
which would linger for as long as 10,000 years, blocking out most of the
Sun's light and heat.
Astronomers had thought that the amount of dust around the inner planets
remains fairly constant because dust from the break-up of comets and
asteroids is balanced by dust falling into the Sun. But this can be upset by
just a single large comet.
Napier and his colleagues believe that the Earth has already suffered at
least once from the effects of comet dust. Data collected in the 1980s shows
an unexpectedly large amount of minute interplanetary dust particles, each
with a mass of about a nanogram. The excess can be explained if a giant
comet broke up in the inner Solar System around 70,000 years ago--the onset
of the last ice age. "I think we should be looking for cometary dust in
polar cores," says Napier.
Napier rates the chance of being swamped by comet dust as 1 in 100,000, the
same as a chance of a collision with a near-Earth object. Others are more
doubtful. "I don't know if we've discovered enough comets to do a
statistical analysis," says Robert McMillan of the University of Arizona's
Spacewatch project, which tracks near-Earth objects.
But David Williams of University College London, who served on the British
government's Near Earth Objects task force last year, agrees with Napier
that work needs to be done on the risks posed by comets. "This area is
perhaps one that's opening up now," he says. "We thought it was too
controversial for the report."
More at: Monthly Notices of the Royal Astronomical Society (vol 321, p 463)
) Copyright New Scientist, RBI Limited 2001
==================================================================
(2) TEMPORAL VARIATION OF THE ZODIACAL DUST CLOUD
W.M. Napier, Armagh Observatory
A Markov chain model has been constructed to investigate fluctuations in the
mass of the zodiacal cloud. The cloud is specified by a three-dimensional
grid, each element of which contains the number of dust particles as a
function of semi-major axis, eccentricity and mass. The evolutionary
pathways of dust particles due to radiation pressure are described by fixed
transition probabilities connecting the grid elements. Other elements are
absorbing states representing infall to the Sun or ejection to infinity:
particles entering these states are removed from the system. Particles are
injected through the breakup of comets entering short-period,
high-eccentricity orbits at random times, and are subject to the
Poynting-Robertson effect and removal through collisional disintegration and
radiation pressure. The main conclusions are that the cometary component of
the zodiacal cloud is highly variable, and that in the wake of giant comet
entry into a short-period, near-Earth orbit, the dust influx to the Earth's
atmosphere may acquire a climatically significant optical depth. Copyright
2001, Blackwell Science Ltd
==================================================================
(4) MIR FALLS TO EARTH SAFELY, AS PLANNED
http://news.bbc.codot uk/hi/english/sci/tech/newsid_1236000/1236899.stm
============================
* LETTERS TO THE MODERATOR *
============================
(9) GIORDANO BRUNO CRATER
>From Paul Withers <withers@LPL.Arizonadot edu>
Hi Benny,
I hear that my work on this interesting crater has been discussed on CCNet
recently. Some of my work is available at
http://www.lpl.arizonadot edu/~withers/papers.html for anyone who's interested
beyond the Sky and Tel story. I intend to put the Meteoritics paper up on
there when I get a nice PDF from the journal. I don't follow this discussion
forum regularly, but I am happy to answer questions about the work if they
appear in my email inbox.
Cheers,
Paul
PS I agree with an early rebuttal paper on this subject - Gervase's text is
much more consistent with a meteor in the Earth's atmosphere than with an
impact on the Moon.
Paul Withers Office +1 520 621 1507
Lunar and Planetary Laboratory, Home +1 520 327 4827
University of Arizona, Tucson, Fax +1 520 621 4933
AZ 85721, USA Email withers@lpl.arizonadot edu
==================================================================
(12) METEOROIDS AND ELECRTOMAGNETIC PULSE
>From Luigi Foschini <foschini@tesre.bo.cnrdot it>
Dear James,
you can look at:
- - M. Beech, L. Foschini: A space charge model for electrophonic bursters.
Astronomy and Astrophysics 345 (1999) L27.
- - M. Beech, L. Foschini: Leonid electrophonic bursters. Astronomy and
Astrophysics 367 (2001) 1056.
for EMP from airburst of small asteroids/comets;
and:
- - L. Foschini: Electromagnetic interference from plasmas generated in
meteoroid impacts.
Europhysics Letters 43 (1998) 226.
for EMP from hypervelocity impacts.
Greetings,
Luigi
Dr. Luigi Foschini
Istituto TeSRE - CNR
Via Gobetti 101, I-40129 Bologna (Italy)
Tel. +39 051.6398706 - Fax +39 051.6398724
Email: foschini@tesre.bo.cnrdot it
Home page: http://tonno.tesre.bo.cnrdot it/~foschini/
==================================================================
(13) METEOR FIREBALLS AND ELECTROMAGNETIC PULSE
>From Colin Keay <phcslk@cc.newcastledot edu.au>
Lightning strokes are a natural source of EMP's as one may easily verify by
having a radio or TV on during a thunderstorm. The EMP from an asteroid
entry would last for a few seconds and be
generated in the same way as the em radiation giving rise to the anomalous
sounds from large meteor fireballs.
See: Colin S L Keay, "Anomalous Sounds from the Entry of Meteor Fireballs"
SCIENCE, Vol 210, pp. 11-15, 1980 October 3.
and
Colin S L Keay, "Progress in Explaining the Mysterious Sounds Produced by
Very Large Meteor Fireballs" Journal of Scientific Exploration, Vol 7, No 4,
pp. 337-354, 1993.
I hope these will be enlightening. In the case of an asteroid entry I would
expect the em radiation strength would be as extreme as from a large nuclear
blast in the atmosphere, with drastic consequences for all but the most
heavily protected electronic equipment.
Cheers ..... Colin Keay
University of Newcastle, NSW.
==================================================================
(16) AND FINALLY: SHOCK, HORROR, AS NASA DECLINES TO PAY PARKING FEE FOR
LANDING ON EROS
>From Orbital Development <gnemitz@orbdev.com>
Mr. Gregory Nemitz
3672-A Bancroft St.
San Diego, CA 92104
USA Tel: 619-528-0520
gnemitz@orbdev.com
http://www.orbdev.com
22 March 2001
SAN DIEGO, CA
FOR IMMEDIATE RELEASE
NASA's General Counsel to Refer Eros Ownership Dispute to Department of
State
In a first ever government acknowledgment of the possibility of a right to
ownership of a property in Space, NASA's General Counsel, Edward Frankle
offers Orbital Development (http://www.orbdev.com) to send the company's
claim of ownership of 433 Eros, to the US Department of State for guidance.
This is the first known instance where a US government official admitted
that Space Property Rights may exist.
NASA's NEAR Shoemaker spacecraft landed on the asteroid 433 Eros on 12
February, 2001. A few days later, the asteroid's owner, Gregory W. Nemitz of
Orbital Development, based in San Diego, California, sent a letter of
invoice (http://www.orbdev.com/010216.html) to Dan Goldin, NASA's Head
Administrator, for parking/storage fees of $20 for the next century's rent.
In reply (http://www.orbdev.com/010309.html) to OrbDev's invoice, and in
acknowledgment that a property right to Eros may exist, Mr. Frankle writes:
"Should you submit facially reasonable material supporting your claim, NASA
will send it, along with your original letter, to the Department of State
for its advice and guidance."
The lengthy letter in response (http://www.orbdev.com/010322.html) by Mr.
Nemitz gives a very detailed rationale on exactly why Mr. Nemitz is indeed
the owner of 433 Eros.
In the letter to Mr. Frankle, Mr. Nemitz writes: "If the claim is in an
uncharted area of law, it is absolutely not immediately dismissable, in
fact, it is quite the opposite situation. If the claim is not in violation
of any laws, if it does not encroach on any previous claim, and especially
if the qualities of the claim can trace a history of reasonable precedents,
it is in fact a very valid claim.
Mr. Nemitz's response also states: "If my claim can be viewed as
unperfected, it cannot be invalid for being imperfect. The claim exists, my
full property rights remain valid, and my claim is absolutely not premature
nor inappropriate."
In addition, the response states: "In principle, the very foundation of a
representative form of government resides in the public contract among those
governed by mutual consent, which allows government to protect their
individual and property rights. If any government or Treaty to which
governments adhere makes private ownership of property in space illegal,
they've lost their only legitimate footing to BE a government of, for, and
by the people who view Space as a frontier."
Orbital Development is a consultancy for Space and Lunar Development.
Founded in 1992, the firm has worked on several space projects and with many
notable "New Space" companies. Mr. Nemitz, the company Founder, is an
Advocate in the Space Frontier Foundation, a former president of the San
Diego L-5 Society, a branch of the National Space Society, and has been a
space development activist since 1988.
Please Direct Inquires to:
Orbital Development
Mr. Gregory Nemitz
3672-A Bancroft St.
San Diego, CA 92104
USA Tel: 619-528-0520
gnemitz@orbdev.com
http://www.orbdev.com
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