PLEASE NOTE:
*
CCNet 130/2002 - 14 November 2002
--------------------------------
"In October 2000, the Near-Shoemaker spacecraft lightly
touched down
on the 13-by-13-by-33- km (8 by 8 by 20 miles) Eros asteroid. It
was the
first time a probe had landed on an asteroid. Its close scrutiny
of Eros
revealed many strange features - such as flat-bottomed craters
filled with
a peculiar bluish dust, and a puzzling lack of small craters.
Unexplained
by conventional understanding, Dr Foot believes that mirror
matter provides
an answer.... Sounds far-fetched - some believe so. However,
experiments are underway to confirm or deny the existence of this
strange, potentially significant but as yet undetected component
of the
cosmos."
--David Whitehouse, BBC News Online, 13 November 2002
(1) MIRROR MATTER MYSTERY
BBC News Online, 13 November 2002
(2) MIRROR MATTER IN THE SOLAR SYSTEM: NEW EVIDENCE FOR MIRROR
MATTER FROM
EROS
Astrophysics, abstract
(3) CATCH A SHOOTING STAR! NASA SCAN FOR LEONID METEOR SHOWER
Andrew Yee <ayee@nova.astro.utoronto.ca>
(4) DEFLECTING NEOS IN ROUTE OF COLLISION WITH THE EARTH
A. Carusi et al.
(5) QUANTIFYING THE RISK POSED BY POTENTIAL EARTH IMPACTS
S.R. Chesley et al.
(6) RENE THOM (1923 - 2002): INVENTOR OF CATASTROPHE THEORY
The Daily Telegraph, 13 November 2002
(7) BIBLICAL PLAGUES
Teemu Mäkinen <tmakinen@engin.umich.edu>
(8) NEO DEFLECTION
Andy Hollis <andrewhollis@supanet.com>
(9) AND FINALLY: THE MCNAUGHT/ASHER PREDICTIONS FOR 2002 (I would
put money
on this!)
Rob H McNaught and David J Asher
===========
(1) MIRROR MATTER MYSTERY
>From BBC News Online, 13 November 2002
http://news.bbc.co.uk/1/hi/sci/tech/2463143.stm
By Dr David Whitehouse
BBC News Online science editor
Two Australian scientists believe they have found evidence of a
parallel
universe of strange matter within our own Solar System.
Dr Robert Foot and Dr Saibal Mitra, of the University of
Melbourne, report
that close-up observations of the asteroid Eros by the
Near-Shoemaker probe
indicate it has been splattered by so-called "mirror
matter".
Mirror matter is not anti-matter, it is altogether weirder. It is
somehow a
"reflection" of normal matter, a sort of parallel
series of particles
required to restore the balance of the Universe.
Sounds far-fetched - some believe so. However, experiments are
underway to
confirm or deny the existence of this strange, potentially
significant but
as yet undetected component of the cosmos.
Cosmic balance
Mirror matter is a hypothetical form of matter that restores
nature's flawed
left-right symmetry.
Laws of nature, such as the rules that govern the interactions of
fundamental particles, show a high degree of symmetry except that
some laws
are not the same when reflected in a hypothetical mirror.
This means that elementary particles display a preference for
left over
right. In a way, the Universe is left-handed. Why? Nobody knows.
Many physicists are happy with this idea believing that in the
first
instants of the Big Bang everything was perfectly symmetrical.
Only when the
cosmos cooled did it become asymmetric, with a difference
emerging between
left and right.
But some scientists do not accept this. They maintain that the
Universe has
a left-right balance because there exists "mirror
matter" - for every known
particle there is a mirror particle that restores the cosmic
balance.
Dark matter
Mirror matter would produce its own light but we would not be
able to see it
because mirror matter only interacts with our matter via gravity.
Dr Robert Foot believes that mirror matter would have been made
in abundance
in the Big Bang and that it is all around us but we can't see it.
"There could be mirror matter stars, planets and galaxies
out there," he
told BBC News Online.
"In fact, some think that the unseen so-called "dark
matter" of the Universe
could actually be mirror matter," he adds.
"Mirror matter is perfect to explain dark matter. It's dark
and can only be
detected through its gravity."
Dr Foot believes he has found evidence that it is here, closer
than we
believed, and that it had had a measurable effect on our
spaceprobes.
Mysterious force
In October 2000, the Near-Shoemaker spacecraft lightly touched
down on the
13-by-13-by-33-km (8 by 8 by 20 miles) Eros asteroid. It was the
first time
a probe had landed on an asteroid.
Its close scrutiny of Eros revealed many strange features - such
as
flat-bottomed craters filled with a peculiar bluish dust, and a
puzzling
lack of small craters.
Unexplained by conventional understanding, Dr Foot believes that
mirror
matter provides an answer.
He calculates that small objects containing mirror matter could
have struck
the asteroid and left behind precisely the same scars that are
seen. Indeed,
he says there is no other credible explanation.
He also calculates that mirror matter may explain the mysterious
force that
acts on both the Pioneer 10 and 11 deep spaceprobes.
Distant probes
Launched in 1972, the Pioneers are leaving the Solar System in
opposite
directions. Detailed analysis of their trajectory indicates that
they are
both subject to a tiny, unexplained force that is slowing them
down.
Dr Foot believes that mirror matter exerting a drag on the
Pioneers could be
to blame.
Mysterious force: Pioneer 10
"How else can you explain that both Pioneers, on opposite
ends of the Solar
System, experience the same force pushing in the same
direction?" Dr Foot
asks.
In a research paper to be published shortly, Drs Foot and Mitra
suggest that
mirror matter may even have struck the Earth.
He singles out three possible events: the 1908 Tunguska impact in
Siberia
and low-altitude, low-velocity fireballs seen in Spain in 1994
and in Jordan
in 2001.
"Mirror matter could also explain these events," he
told BBC News Online.
Future experiments
Many scientists dismiss mirror matter as wild speculation but
even the
sceptics will have cause for thought if the latest experiments
from the
European Centre for Nuclear Research (Cern) are to be believed.
Experiments involving so-called ortho-positronium - an
arrangement in which
an electron orbits a positron (its antimatter equivalent) - show
that it
decays slightly faster than can be explained.
This could be due, says Dr Foot, to the electrons changing
fleetingly into
mirror matter and then back again.
Experiments at Cern and in Moscow hope to determine in the next
year or so
if mirror matter really does exist.
Copyright 2002, BBC
==========
(2) MIRROR MATTER IN THE SOLAR SYSTEM: NEW EVIDENCE FOR MIRROR
MATTER FROM
EROS
>From Astrophysics, abstract
http://www.arXiv.org/abs/astro-ph/0211067
astro-ph/0211067
From: Robert Foot <foot@physics.unimelb.edu.au>
Date (v1): Mon, 4 Nov 2002 21:18:15 GMT (42kb)
Date (revised v2): Tue, 12 Nov 2002 23:01:42 GMT
(43kb)
Mirror matter in the solar system: New evidence for mirror matter
from Eros
Author: R. Foot, S. Mitra
Comments: Some adjustments to pond discussion, about 20 pages
long
Subj-class: Astrophysics; Space Physics
Mirror matter is an entirely new form of matter predicted to
exist if mirror
symmetry is a fundamental symmetry of nature. Mirror matter has
the right
broad properties to explain the inferred dark matter of the
Universe and
might also be responsible for a variety of other puzzles in
particle
physics, astrophysics, meteoritics and planetary science. It is
known that
mirror matter can interact with ordinary matter
non-gravitationally via
photon-mirror photon kinetic mixing. The strength of this
possibly
fundamental interaction depends on the (theoretically) free
parameter
$\epsilon$. We consider various proposed manifestations of mirror
matter in
our solar system examining in particular how the physics changes
for
different possible values of $\epsilon$. We find new evidence for
mirror
matter in the solar system coming from the observed sharp
reduction in
crater rates (for craters less than about 100 meters in diameter)
on the
asteroid 433 Eros. We also re-examine various existing ideas
including the
mirror matter explanation for the anomalous meteorite events,
anomalous
slow-down of Pioneer spacecraft etc.
FULL ARTICLE AT http://www.arXiv.org/abs/astro-ph/0211067
=============
(3) CATCH A SHOOTING STAR! NASA SCAN FOR LEONID METEOR SHOWER
>From Andrew Yee <ayee@nova.astro.utoronto.ca>
Steve Roy
Media Relations Dept.
Marshall Space Flight Center, Huntsville, AL
steve.roy@msfc.nasa.gov
(256) 544-0034
For release: 11/12/02
Release No.: 02-286
'Catch a shooting star!'
NASA engineers to scan for Leonid meteor shower Nov. 18-19
>From five key points on the globe and from the International
Space Station,
NASA researchers will use special cameras to scan the skies and
report
activity around the clock during the annual Leonid meteor shower
Nov. 18-19.
Sky-gazers in North America and Europe should be able to
"catch" as many as
one meteor every 6 to 10 seconds -- even with a full moon shining
-- during
the peak of the Leonid meteor shower, which occurs when Earth
passes close
to the orbit of the Comet Tempel-Tuttle and debris left in the
comet's path.
Led by the Engineering Directorate at NASA's Marshall Space
Flight Center in
Huntsville, Ala., the research is part of a long-term goal to
protect
spacecraft such as NASA's Chandra X-ray Observatory from
potentially
damaging meteoroids.
"Stargazers should see a great show, even though the full
moon will cut
visibility about 75 percent," said Dr. Rob Suggs, the Space
Environments
Team Lead. "For the past three years, we've had some
astounding Leonid
showers. However, this may be the last opportunity in our
lifetimes
to see a 'storm' of Leonids. Predictions lead us to believe this
could be
the 'grand finale' until 2133."
Using "night-vision" image intensifier video systems
and sky-watchers
outfitted with Palm computer software developed to record visual
counts,
NASA engineers and astronomers will record their observations for
later
analysis.
Despite what their name suggests, "shooting stars" are
not stars at all;
they are meteors. Meteors are produced when bits of cometary or
asteroidal
debris in space, usually between the size of a sand grain and a
pebble,
enter the Earth's atmosphere and burn up, creating a brief --
usually white
-- streak of light.
The Leonids were named such because they appear to radiate out of
the
constellation Leo. The material crossing Earth's path this year
was ejected
from the Comet Tempel-Tuttle at least 100 years ago. Meteor
viewers in the
United States, for example, will see material ejected from the
comet in
1866.
NASA engineers have provided meteor shower rates for many cities
around the
world through the NASA Web site: www.SpaceWeather.com
sponsored by
Science@NASA (http://science.nasa.gov)
Astronomer Mitzi Adams of the Marshall Center also will provide
updates Nov.
18 on the progress of the Leonids to SpaceWeather.com .
NASA's concern, however, isn't the view. Even though today's
satellites are
engineered to withstand a smattering of meteoroid strikes, by
determining
where, when and how the meteors will strike, NASA can take
protective
measures to prevent or minimize damage to spacecraft.
Because the stream from Tempel-Tuttle hits the Earth almost
head-on, the
Leonids are among the fastest meteors known -- entering the
Earth's
atmosphere at 44 miles per second.
Since the Chandra Observatory must travel through the Leonid
debris field,
controllers at its Operations Control Center in Cambridge, Mass.,
will make
sure the satellite is pointed in the exact opposite direction as
the
incoming meteors. They will angle the solar arrays to protect the
sensitive
back of the arrays and minimize the surface area presented to the
meteor
direction.
Protective measures can range from turning a satellite so it
faces the
direction of minimal exposed surface area, to shutting down a
spacecraft's
electronic operations until the storm has passed.
"When a meteoroid hits a satellite, it can heat the impact
site to thousands
of degrees Kelvin -- rivaling the surface temperature of the
Sun," Suggs
said. "Usually the entire meteoroid is vaporized along with
a tiny bit of
the spacecraft."
Considering that meteors are so small, their potential for damage
can be
surprising when their speed is considered.
"They're small, but they move very fast -- about 45 miles
per second (71
kilometers per second)," said Dr. Bill Cooke, an astronomer
at the Marshall
Center.
Cooke says the research data from the Leonid shower will be
analyzed to help
NASA engineers refine their engineering forecasts for spacecraft.
According to Cooke, sky-gazers could see up to 600 meteors per
hour if they
are away from city lights and the sky is clear. In the Eastern
United
States, the shower is predicted to peak near dawn, while in the
Western
United States, it is expected to peak around 2:30 a.m. PST.
However, the
"show" will start Nov. 18 about 10:53 EST with the
Leonid "grazers" --
meteors not dropping into the Earth's atmosphere, but instead
grazing the
atmosphere. Grazers appear as reddish meteors that advance east
to west
across a large part of the sky.
The NASA researchers will monitor the storm from five locations,
each
selected based on meteor forecasts and the area's climate. Sites
include
Huntsville, Ala.; Calar Alto Observatory in southern Spain; Teide
Observatory in the Canary Islands; Apache Point Observatory in
southern
New Mexico; and Kitt Peak National Observatory in southern
Arizona.
Another tool at Marshall's disposal is "forward-scatter
radar" -- an early
warning system built by Suggs, Cooke and Dr. Jeff Anderson, also
of
Marshall's Engineering Directorate.
"Our system is pretty simple," said Suggs. "We use
an antenna and
computer-controlled short-wave receiver to listen for 67 MHz
signals from
distant TV stations."
The transmitters are over the horizon and normally out of range.
When a
meteor streaks overhead, the system records a brief ping -- the
echo of a TV
signal bouncing off the meteor's trail. Like the
image-intensified cameras,
this system is capable of detecting meteors too dim to see with
the unaided
eye.
The Marshall Center has also provided Leonid forecast information
to
operators of spacecraft such as Chandra to help prepare for a
meteor shower.
"By comparing the meteor shower predictions to the actual
meteor counts, we
are laying the groundwork to improve forecasts in the
future," said Suggs.
How to view Leonids:
The golden rule to watching the Leonids -- or any meteor shower
-- is to be
comfortable, according to Cooke and Suggs. Be sure to wrap up
warmly -- a
sleeping bag placed atop a lawn chair facing east is a good way
to enjoy the
show. Put your chair in a clear, dark place with a view of as
much of the
sky as possible. Don't stare at any one place -- keep your eyes
moving
across the sky. Watch for fireballs and streaks -- some will
remain visible
for several minutes or more. The meteors will be radiating from
the Sickle of Leo that will
be rising out of the east-northeast sky. Don't look directly at
the constellation, but at the
area above and around it. And, though you don't need them to see
the
Leonids, a pair of binoculars could come in handy.
For more information:
http://www.SpaceWeather.com/
http://science.nasa.gov/
http://chandra.harvard.edu/
http://www.nsstc.org/
IMAGE CAPTION:
[ http://www1.msfc.nasa.gov/NEWSROOM/news/photos/2002/2002images/Hall1_m.jpg
]
2001 Leonids shower. (Photo credit: Sam Cook of Chattanooga,
Tenn.,
copyrighted)
=============
(4) DEFLECTING NEOS IN ROUTE OF COLLISION WITH THE EARTH
Carusi A, Valsecchi GB, D'Abramo G, Boattini A: Deflecting NEOs
in route of
collision with the Earth ICARUS 159 (2): 417-422 OCT 2002
We consider a small sample of known near Earth objects (NEOs),
both
asteroids and comets, with low minimum orbital intersection
distance (MOID).
Through a simple numerical procedure we generate slightly
different orbits
from this sample in such a way that these bodies will collide
with the Earth
at a specific epoch. Then we study the required change in orbital
velocity
(along track Deltav) in order to deflect these NEOs at different
epochs
before the impact event. The orbital evolution of these NEOs is
performed
through a full N-body numerical integrator. A comparison with
analytical
estimates is also performed in selected cases. Interesting
features in the
Deltav/time before impact plots are found; as a prominent result,
we find
that close approaches to the Earth before the epoch of the impact
can make
the overall deflection easier. (C) 2002 Elsevier Science (USA).
Addresses:
Carusi A, CNR, IASF, Area Ric Tor Vergata, Via del Fosso del
Cavaliere 100,
I-00133 Rome, Italy
CNR, IASF, Area Ric Tor Vergata, I-00133 Rome, Italy
Copyright © 2002 Institute for Scientific Information
===========
(5) QUANTIFYING THE RISK POSED BY POTENTIAL EARTH IMPACTS
Chesley SR, Chodas PW, Milani A, Valsecchi GB, Yeomans DK:
Quantifying the
risk posed by potential Earth impacts ICARUS 159 (2):
423-432 OCT 2002
Predictions of future potential Earth impacts by near-Earth
objects (NEOs)
have become commonplace in recent years, and the rate of these
detections is
likely to accelerate as asteroid survey efforts continue to
mature. In order
to conveniently compare and categorize the numerous potential
impact
solutions being discovered we propose a new hazard scale that
will describe
the risk posed by a particular potential impact in both absolute
and
relative terms. To this end, we measure each event in two ways,
first
without any consideration of the event's time proximity or its
significance
relative to the so-called background threat, and then in the
context of the
expected risk from other objects over the intervening years until
the
impact. This approach is designed principally to facilitate
communication
among astronomers, and it is not intended for public
communication of impact
risks. The scale characterizes impacts across all impact
energies,
probabilities and dates, and it is useful, in particular, when
dealing with
those cases which fall below the threshold of public interest.
The scale
also reflects the urgency of the situation in a natural way and
thus can
guide specialists in assessing the computational and
observational effort
appropriate for a given situation. In this paper we describe the
metrics
introduced, and we give numerous examples of their application.
This enables
us to establish in rough terms the levels at which events become
interesting
to various parties. (C) 2002 Elsevier Science (USA).
Addresses:
Chesley SR, CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena,
CA 91125 USA
CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA
Univ Pisa, Dipartimento Matemat, I-56100 Pisa, Italy
CNR, IASF, Rome, Italy
Copyright © 2002 Institute for Scientific Information
===========
(6) RENE THOM (1923 - 2002): INVENTOR OF CATASTROPHE THEORY
>From The Daily Telegraph, 13 November 2002
http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2002/11/13/db1301.xml&sSheet=/opinion/2002/11/13/ixopright.html
René Thom, the French mathematician who died on October 25 aged
79, was best
known as the inventor of catastrophe theory, which seeks to
describe, in a
way that is impossible using differential calculus, those
situations in
which gradually changing forces lead to so-called catastrophes,
or abrupt
changes.
Catastrophe theory has been applied with mixed results to a
number of
different phenomena in the real world, such as the stability of
ships at sea
and their capsizing, earthquakes, cliff falls, the development of
clouds and
bridge collapse.
It has been applied even less successfully to "social"
phenomena such as the
"fight-or-flight" behaviour of animals, prison riots,
the outbreak of war
and stock market crashes.
More fruitfully, perhaps, the theory inspired the later works of
Salvador
Dalí, whose Topological Abduction of Europe: Homage to René
Thom (1983),
showed an aerial view of a fractured landscape juxtaposed with
Thom's
equation that attempts to explain it.
Thom's expertise was in a mathematical field known as topology,
which
studies the shapes and symmetries of abstract multi-dimensional
geometric
objects; catastrophe theory developed as a by-product of this
discipline.
Thom argued that there is only a limited number of ways in which
sudden and
catastrophic events take place, and suggested a methodology by
which these
processes could be described with their own abstract mathematical
forms.
Thom's work involved the visualisation or computer simulation of
some very
complex higher-dimensional shapes, including such things as
"periodic
folds", "pinching bifurcations", and "saddle
connection catastrophes" - or,
more poetically, the "cusp", the
"swallowtail" and the "butterfly".
He believed that this methodology could be developed in order to
predict
sudden shifts in behaviour which might arise from relatively
small changes
in circumstances.
Thom's theory, set out in a paper published in 1968, then
elaborated in
Structural Stability and Morphogenesis (1972), caused a sensation
in the
mathematical world and analysts were soon trying to apply it in
fields such
as biology, sociology and finance, but with no consistent
results.
Catastrophe theory became an established area of mathematical
research and
had a notable impact on the development of new ideas, in
particular chaos
theory. However, its wider relevance remains dubious and many
scientists and
mathematicians are unconvinced of its value.
When Thom won the Fields Medal (which is the mathematical
equivalent of the
Nobel Prize) in 1958, it was not for his work on catastrophe
theory, but for
his work on "cobordism" theory, an even more obscure
branch of pure
mathematics which has been defined as "a way of organising
and classifying
manifolds whose stable tangent bundles admit additional
structure".
René Frédéric Thom was born at Montbéliard, near the border
with
Switzerland, on September 2 1923. His parents were shopkeepers.
A gifted child, by the age of 10 he was said to have been able to
visualise
shapes in four dimensions. He won a scholarship to Collége
Cuvier at
Montbéliard and received his baccalaureat in elementary
mathematics from
Besançon in 1940.
After the German invasion, Thom's parents sent him and his
brother south to
avoid unpleasantness, although they themselves remained in
Montbéliard.
Thom and his brother eventually reached Switzerland but soon
afterwards
returned to France. Thom then moved to Lyon to continue his
education,
receiving a baccalauréat in philosophy in 1941.
The same year he entered the Lycée Saint-Louis in Paris and
applied to enter
the Ecole Normale Superiéure, getting in at the second attempt
in 1943.
He became strongly influenced by the pure mathematician Henri
Cartan and the
so-called "Bourbaki" school of mathematics and, in
1946, moved to Strasbourg
to study under Cartan. In 1951 he earned a doctorate in
mathematics for a
thesis supervised by Cartan, entitled Fibre Spaces in Spheres and
Steenrod
Squares.
The same year Thom was awarded a travel scholarship to visit
America, where
he met Einstein and the mathematicians Hermann Weyl and Norman
Steenrod, and
attended seminars given by Kunihiko Kodaira.
After returning to France in 1953, Thom taught at Grenoble
University for a
year before moving to Strasbourg University, where he was
appointed
professor in 1957.
In 1964 he moved to the Institut des Hautes Etudes Scientifique
at
Bures-sur-Yvette, near Paris. The mathematics faculty at that
time was
dominated by Thom's colleague Alexander Grothendieck, whose
seminars
attracted the best students.
Rather put out by his colleague's technical superiority, Thom
left the
strictly mathematical world to tackle more general and
philosophical notions
such as the theory of catastrophe.
He also wrote papers on linguistics, philosophy and theoretical
biology. He
retired in 1988.
Thom regarded his mathematics as more closely related to poetry
and
philosophy than empirical, experiment-based science, on which he
tended to
look down: "Proving," he once argued, "is not a
natural activity for
mathematicians."
On another occasion he declared that: "If one must choose
between rigour and
meaning, I shall unhesitatingly choose the latter."
In his memoirs, What Mad Pursuit, the British scientist Francis
Crick
recalled meeting Thom in the early 1960s at a scientific meeting
held in
Italy to discuss progress on cracking the chemical code of DNA.
Almost immediately, Crick recalled, Thom informed him that some
of his
[Crick's] recent research was wrong because, though it had been
verified
experimentally, it did not conform with mathematical theory.
Thom, Crick observed with wry amusement, referred disparagingly
to
laboratory-based science as "Anglo-Saxon".
Thom is survived by his wife, Suzanne, and by a son and two
daughters.
Copyright 2002, The Daily Telegraph
==========================
* LETTERS TO THE MODERATOR
==========================
(7) BIBLICAL PLAGUES
>From Teemu Mäkinen <tmakinen@engin.umich.edu>
Dear Benny,
concerning the BBC Biblical plague documentary, I remember seeing
one with
an exactly identical line of reasoning a month ago on the
Discovery channel.
What I failed to grasp back then (and still do) is the patently
absurd
assumption (at least evident in the document that I saw) that the
cataclysm
would somehow lend credence to a literal interpretation of that
part of the
Bible (i.e., that the passage is a more or less objective
narration of
actual historical events). The problem is, of course, that the
Hebrews would
have been some nimble-footed people indeed, had they first
witnessed the
effects of the eruption (the plagues), then been given the
permission to
leave by the pharaoh, then managed to pass the Reed Sea some 3
hours after
the eruption, just in time before the tsunami arrived. If
anything, this
study should indicate that the original storytellers of the Bible
used their
creative license not unlike a present-day action movie director,
throwing in
known special effects to divert the attention of the audience
from
shortcomings of the plot.
Maybe the BBC documentary has a more rational agenda?
Sincerely yours,
Teemu Makinen
tmakinen@engin.umich.edu
============
(8) NEO DEFLECTION
>From Andy Hollis <andrewhollis@supanet.com>
Dear Benny,
I am pleased to see that the Hollywood idea of blasting Earth
Impacting
bodies to pieces seems no longer to be considered realistic. To
my
simplistic view blasting a projectile into grapeshot seemed no
solution and
would only make the disaster more widespread.
Nudging the body to miss does seem a more satisfactory solution
to the
problem. However one nagging thought still worries me about this
solution.
Fine to deflect the body away by whatever is the chosen method,
however this
will still leave a modified orbit that will intersect that of the
Earth. To
me the solution is not a permanent one but merely one of
postponing the
eventuality.
A two stage solution seems needed to my mind. Yes the initial
deflection is
necessary but also a second deflection when the body is near
aphelion to
modify the orbit so that it will not intersect that of the Earth
at some
future date.
Have I missed something?
Andy Hollis
===========
(9) AND FINALLY: THE MCNAUGHT/ASHER PREDICTIONS FOR 2002 (I would
put money
on this!)
By Rob H McNaught and David J Asher
http://www.arm.ac.uk/preprints/386.pdf
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