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(meteorobs) Excerpts from "CCNet, 2 November 1999"
------- Forwarded Message
From: Benny J Peiser <b.j.peiser@livjm.acdot uk>
To: cambridge-conference@livjm.acdot uk
Subject: CCNet, 2 November 1999
Date: Tue, 2 Nov 1999 12:42:07 -0500 (EST)
CCNet, 2 November 1999
[...]
(4) CREATING THE MODEL COMET
Ron Baalke <baalke@ssd.jpl.nasadot gov>=20
(5) SURVIVAL OF LIFE ON ASTEROIDS, COMETS & OTHER SMALL BODIES
B.C. Clark et al., LOCKHEED MARTIN
[...]
(8) MAGNETIZATION OF ASTEROIDS
R. Bingham and M. Dawson, RUTHERFORD APPLETON LAB
[...]
=======================================================
(4) CREATING THE MODEL COMET
>From Ron Baalke <baalke@ssd.jpl.nasadot gov>=20
=20
Creating the Model Comet
=20
By Andrew Bridges
=20
Nov 01 1999 05:50:27 ET
=20
When they deign to grace the heavens above, comets are among the=20
brightest objects visible in the nighttime sky.
=20
But up close, peering within the bright coma and tail that distinguish=20
it, a comet's nucleus can be unexpectedly dark, often blacker than=20
coal.
=20
Scientists are interested in comets because they are thought to=20
contain, preserved by the deep freeze of space, the original =20
ingredients that made up our solar system, including organic material=20
that may have helped spark life here on Earth.
=20
But comets' nuclei are obscured by abundant clouds of gas and dust.=20
This makes them difficult to study from Earth. And rendezvousing with=20
them -- or any small body, like an asteroid -- in space is an even=20
trickier proposition.
=20
Due to the fact comets are so fast moving, and small -- often just=20
miles or kilometers across -- spacecraft are increasingly being given=20
broad autonomy in navigating the final steps to close encounters.
=20
Full story here:
=20
http://www.space.com/news/planetarymissions/comet_model_991101.html
=======================================================
(5) SURVIVAL OF LIFE ON ASTEROIDS, COMETS & OTHER SMALL BODIES
B.C. Clark*), A.L. Baker, A.F. Cheng, S.J. Clemett, D. McKay, H.Y.=20
McSween, C.M. Pieters, P. Thomas, M. Zolensky: Survival of life on=20
asteroids, comets and other small bodies. ORIGINS OF LIFE AND EVOLUTION =
OF THE BIOSPHERE, 1999, Vol.29, No.5, pp.521-545
*) LOCKHEED MARTIN ASTRONAUT,ADV PLANETARY STUDIES GRP,DENVER,CO
The ability of living organisms to survive on the smaller bodies in our =
solar system is examined. The three most significant sterilizing=20
effects include ionizing radiation, prolonged extreme vacuum, and=20
relentless thermal inactivation. Each could be effectively lethal, and=20
even more so in combination, if organisms at some time resided in the=20
surfaces of airless small bodies located near or in the inner solar=20
system. Deep within volatile-rich bodies, certain environments=20
theoretically might provide protection of dormant organisms against=20
these sterilizing factors. Sterility of surface materials to tens or=20
hundreds of centimeters of depth appears inevitable, and to greater=20
depths for bodies which have resided for long periods sunward of about=20
2 A.U. Copyright 1999, Institute for Scientific Information Inc.
=======================================================
(8) MAGNETIZATION OF ASTEROIDS
R. Bingham*), and M. Dawson: Magnetization of asteroids. PHYSICA=20
SCRIPTA, 1999, Vol.T82, p.137
*) RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND
It is shown that non-parallel density and temperature gradients can=20
produce magnetic fields which can account for the asteroid Gaspra=20
surface magnetic field of about one Gauss.
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
(9) DAMAGE FROM COMET-ASTEROID IMPACTS WITH EARTH
J.G. Hills*) & M.P. Goda: Damage from comet-asteroid impacts with=20
earth. PHYSICA D, 1999, Vol.133, No.1-4, pp.189-198
*) LOS ALAMOS NATL LAB,DIV THEORET,THEORET ASTROPHYS GRP,T-6,MS=20
B288,LOS ALAMOS,NM,87545
Only a small fraction of the Earth-crossing asteroids, ECAs, have been=20
found and cataloged. Uncataloged ECAs can hit the atmosphere of Earth=20
without warning. Long-period comets may give as little as two months=20
warning before impact. The damage ranges from fires and blastwaves from =
energy dissipation in the atmosphere to craters, earthquakes, and=20
tsunami from ground impact. Tsunami damage is particularly severe. An=20
asteroid 5-6km in diameter impacting in the mid Atlantic would cause=20
substantial tsunami damage to both Europe and North America: the=20
tsunami would run all the way to the Appalachians in the upper=20
two-thirds of the United States and to the mountains of the Iberian=20
Peninsula in Europe. Tsunami heights along the Iberian Peninsula can=20
reach several hundred meters. The tsunami heights would be less in=20
Northern Europe due to the shallow continental shelf in this region.=20
(C) 1999 Elsevier Science B.V. All rights reserved.
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
10) PEER REVIEWED SCIENCE FICTION
=20
>From Benny J Peiser <b.j.peiser@livjm.acdot uk>
=20
As Kelly Beatty and Andrew Glikson have pointed out, one of the main=20
consequences of the WWW is the fact that we are increasingly inundated =
by a flood of scientific (and pseudo-scientific) information which=20
assails them from all directions, most of it 'unrefereed' and in the=20
form of press releases and self-promotion etc.=20
=20
Part of my job as the moderator of the CCNet is to sift through this =20
information an re-distribut a *selected* portion, selected on the basis =
of subject material and (to some extent) the 'quality' of the material. =
Given that this selection process is done by a single person, and=20
often on an the basis of ad hoc decisions, I try to be as liberal as=20
possible in order not to restrict the information flow too much.=20
=20
The problems involved in this selection process, however, are not=20
always related to unrefereed material circulating on the WWW. A recent=20
abstract search has come up with rather weired paper by the Russian=20
scientists E.M. Drobyshevskii on the =93Danger of the explosion of=20
Callisto and the priority of space missions=94 which was published in =
an=20
peer reviewed journal under the auspice of the American Institute=20
of Physics.
=20
I am told that Count Edouard Drobyshevskii is a proponent of exploding=20
planets, through a variety of schemes, including a curious hypothesis=20
for "runaway" impacts in which a crater forms, then its ejecta creates=20
even more craters, and so on until the entire planet is resurfaced or=20
destroyed. In the 1980s, Drobyshevkskii published a paper in=20
which he claimed that Phobos was a planet that had just barely survived =
explosion, as evidenced by its layered fracture pattern, which supports =
his piezoelectric energy storage hypothesis. These explosions, of=20
course, create the asteroids and the comets, and all of the albedo=20
markings on the Earth, Moon and other planets.
=20
Now Drobyshevskii's paper provides us with a good example that problems =
of science communication are often totally unrelated to the internet:=20
after all, his paper has been refereed and is written by someone with=20
apparently-solid academic credentials. How, then, should such=20
peer-reviewed information be handled on the CCNet (and in general)?=20
Does the fact that this unsubstantiated and rather apocalyptic paper=20
was published in a reputable, peer-reviewed journal make it more=20
acceptable and 'better' than unrefereed press releases as a source of=20
information? Clearly, what is relevant here is not the form of its=20
presentation but the way in which it is received. Instead of being=20
worried about the circulation of flawed and misleading scientific=20
information (which, as this example impressively shows is a logical=20
byproduct of open scientific debates), it is the task of skeptical=20
researchers to attempt a falsification of such claims and predictions.=20
While this unthankful task is time-consuming, it certainly is, I would=20
argue, a major part scientific research. In fact, such critical=20
response is required for *all* scientific (or pseudo-scientific) claims =
- - no matter how rediculous they are or appear to be. Only by proving=20
such nonsense wrong a more realistic picture of our cosmic environment=20
can be established.
=20
But what is a reputable journal? As far as I am aware, the Proceedings=20
of the National Academy of Sciences (USA) is NOT refereed, as such.=20
Members/Fellows can publish more-or-less what they want there. The=20
early papers by the Alvarez team (which, due to its controversial=20
theory, may had been rejected by reviewers of other journals), and the=20
first major paper by Raup & Sepkoski on periodicities in mass=20
extinctions were published in this way. Should papers, I ask, published =
there not be admissable to CCNet too?
=20
I leave you with Count Edouard Drobyshevskii=92s paper that raises even =
more such philosophical questions. Rather than being outraged or=20
embarrassed about its contents, Drobyshevskii=92s claims should be=20
answered and rejected in a sober and matter-of-fact manner. As long as=20
his apocalyptic theory remains unchallenged by his critics, it will be=20
perceived as a scientific hypothesis just as valid as others. Only=20
extreme masochists, I guess, would be happy with the prospect of a=20
"nuclear winter every 60 years".....:-)=20
=20
Benny J Peiser
=20
-------------
=20
E.M. Drobyshevskii: Danger of the explosion of Callisto and the=20
priority of space missions. TECHNICAL PHYSICS, 1999, Vol.44, No.9,=20
pp.1009-1013
=20
RUSSIAN ACADEMY OF SCIENCE,AF IOFFE PHYSICOTECH INST,
ST PETERSBURG 194021,RUSSIA
=20
Ice is a protonic conductor, as has been demonstrated many times by=20
electrolysis experiments. The dirty ices which comprise the thick=20
(similar to 10(3) km) crusts of several distant moonlike bodies are=20
subjected to bulk electrolysis by currents excited by the motion of=20
such bodies in cosmic magnetic fields (for example, Voyager-1 measured=20
a current amounting to similar to 10(7) A flowing through the Jovian=20
satellite Io and its surroundings). The accumulation of electrolysis=20
products in ice in amount equal to 10-15 wt. % renders such a solid=20
solution capable of detonation. Global explosions of the crusts of=20
moonlike bodies account for the origin and the known properties of many =
asteroids, short-period comets, planetary rings and small satellites,=20
the formation of Titan's atmosphere, the differences between Jupiter's=20
Galilean satellites, etc. Many predictions made on this basis have=20
already been confirmed, and others are awaiting testing. According to=20
all the signs, only the ices of the fourth Galilean satellite Callisto=20
have not yet exploded. If they explode, the Earth will be subjected to=20
concentrated bombardment by cometary nuclei, which will create a=20
'nuclear winter' once every 60 years on the average. Therefore, a very=20
high priority should be assigned to in situ investigations of Callisto=20
for the purpose of determining the degree of saturation of its ices=20
with electrolysis products. (C) 1999 American Institute of Physics.=20
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