PLEASE NOTE:
*
CCNet 86/2001 - 12 July 2001
---------------------------
"We think we're seeing orbits cluster, that is, orbits of
several
moons fall in the same general plane, just as asteroids cluster.
And with
asteroids that cluster, the belief is they are pieces of what
once was a
big asteroid that got hit by something. It's possible that we're
seeing
the same thing with the satellites."
--Carl W. Hergenrother, Lunar and Planetary Laboratory
(LPL), 11 July 2001
"Stargazers here on Earth get excited whenever a comet comes
close
to the Sun. Comets -- icy visitors from the outer solar system --
are
easily vaporized. Even a little sunlight will cause one to bubble
and
froth, dispensing a tail that stretches millions of kilometers
through
space and far across the night sky. Bright comets are
unforgettable sights.
Now imagine a solar system in which not one but billions of
comets are
vaporizing -- all at the same time! That's what astronomers may
have
found around an aging star called IRC+10216."
--NASA News, 11 July 2001
"Comets and asteroids have been blamed for a lot of things
before.
Shaping Earth. Jumpstarting life. Wiping out dinosaurs. Even
possibly
altering human evolution. But never sex. [...] Now a new study
out of
Caltech and NASA's Jet Propulsion Laboratory has used digital
organisms to
simulate life before sex and yielded a possible mechanism for
instigating
Earth's first courtship."
--Rob Britt, Space.com, 10 July 2001
(1) SATURNALIA: EVIDENCE FOR EXPLODED MOON THEORY?
Andrew Yee <ayee@nova.astro.utoronto.ca>
(2) SATURN'S DIRTY DOZEN
Nature Science Update, 12 July 2001
(3) SIZZLING COMETS CIRCLE A DYING STAR
NASA Science News, 11 July 2001
(4) THE ORIGIN OF SEX: COSMIC SOLUTION TO ANCIENT MYSTERY
Space.com, 10 July 2001
(5) A PIECE OF HEAVENS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(6) THE MOON AND PLATE TECTONICS: WHY WE ARE ALONE
SpaceDaily, 11 July 2001
(7) BEATLES, WILSON & SPRINGSTEEN ARE STARS IN THE SKY, TOO
Yahoo! News, 10 July 2001
(8) UK UPDATE ON NEO ACTIVITIES
Duncan Steel <D.I.Steel@salford.ac.uk>
(9) MORE PUZZLES ABOUT MARTIAN METEORITES
John Michael Williams <jwill@AstraGate.net>
(10) ROCKS FROM MARS: SHALLOW IMPACTS CAN DO THE TRICK
James Marple <jesl@carolina.net>
(11) L'ENIGME VOLCANIQUE
Hermann Burchard <burchar@mail.math.okstate.edu>
(12) MOON HOAX
Phil Plait <badastro@badastronomy.com>
(13) SHOCK, HORROR: ACC DOESN'T BELIEVE MOON HOAX EITHER
Sir Arthur C Clarke
(14) RE: QUESTIONS ABOUT CELESTIAL OBJECTS COLLIDING WITH THE
EARTH
Bob Kobres <bkobres@uga.edu>
(15) AND FINALLY, THE FULL MONICA: SOCIAL SCIENCE AT ITS BEST....
Yahoo! News, 8 July 2001
==========
(1) SATURNALIA: EVIDENCE FOR EXPLODED MOON THEORY?
From Andrew Yee <ayee@nova.astro.utoronto.ca>
News Services
University of Arizona
Tucson, Arizona
Contact Information:
Carl Hergenrother, 520-621-4655, chergen@lpl.arizona.edu
Jul 11, 2001
Twelve New-Found Moons of Saturn Are Collisional Remnants of
Larger Moons
By Lori Stiles
Astronomers have discovered 12 more moons around Saturn. And they
have
evidence these once were just 3 or 4 moons, minding their
business, orbiting
the planet like all regular saturnian moons do today.
The 12 new-found moons are in irregular orbits that suggest they
are the
collisional remnants of larger parent moons, once securely
captured in, but
later blasted from, their saturnian orbits.
Using several medium-to-large sized telescopes, large-format CCD
arrays that
photograph big areas of sky, and computers that process multiple
gigabytes
of data each night, teams of astronomers collaborated last fall
in a search
for so-called "irregular" moons around the gas giant.
Saturn was known to have six relatively large moons and 12 minor
moons. All
except one minor moon, Phoebe, discovered in 1898, are classified
as regular
satellites because they move along nearly circular orbits in the
planet's
orbital plane, revolving in the same direction as the planet
spins.
The 12 new-found satellites are irregular -- meaning they orbit
outside the
plane of Saturn's equator -- and it appears that their orbits
cluster in
three, possibly four, distinct groups, said Carl W. Hergenrother
of the UA
Lunar and Planetary Laboratory (LPL).
"We think we're seeing orbits cluster, that is, orbits of
several moons fall
in the same general plane, just as asteroids cluster,"
Hergenrother said.
"And with asteroids that cluster, the belief is they are
pieces of what once
was a big asteroid that got hit by something. It's possible that
we're
seeing the same thing with the satellites."
Brett Gladman of the Observatoire de la Cote d'Azur in France,
J.J.
Kavelaars of McMaster University in Canada, and Matthew Holman of
the
Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.,
discovered
the irregular saturnian moons in August, September and November,
2000, using
the 2.2-meter (87-inch) European Southern Observatory in Chile,
the
3.6-meter (142-inch) Canada-France-Hawaii Telescope in Hawaii,
and the
1.2-meter (48-inch) Mount Hopkins telescope in Arizona.
Hergenrother, Stephen M. Larson and Rob Whiteley -- all of the
LPL -- and
Dennis Means of the UA Steward Observatory used the Steward
Observatory's
1.5-meter telescope (61-inch) in the Santa Catalina Mountains
north of
Tucson and the 2.3-meter (90-inch) Bok Telescope on Kitt Peak to
observe the
moons for more precise information on their orbits.
Others doing this "recovery" work to help define the
satellite orbits used
the 4-meter Kitt Peak telescope, the 5-meter Palomar telescope
and
2-to-3-meter class European telescopes.
The research is reported in the article, "Discovery of 12
satellites of
Saturn exhibiting orbital clustering," in the July 12
Nature.
Astronomers in 1997 and 1999 discovered five irregular satellites
around
Uranus, and in 1999 - 2000 discovered another 12 irregular
satellites around
Jupiter, previously known to have eight. The UA Spacewatch on
Kitt Peak
discovered one of the new-found jovian moons.
Almost all of the irregulars discovered since 1997 cluster in
easily
discernible groupings, the astronomers note in their article.
"The difficult question is whether the disruptions occurred
during the
capture process itself when the planets formed long ago, or
whether intact
moons were captured at that time into orbits near the present
grouping and
these single moons were subsequently shattered and scattered by
intruding
comets or asteroids during the subsequent (more than
4-billion-year solar
system history)," they wrote.
The most probable theory is that each cluster is the remains of a
once-intact moon smashed by a collision sometime after the
planets were
formed, according to their analysis.
Saturn must have captured the original parent moons during
planetary
formation, as the objects passed through Saturn's surrounding
proto-planetary gas cloud, Hergenrother said.
An alternative theory is that the moons were captured when Saturn
suddenly
increased in mass -- in which case the moons would all be
prograde, moving
around the planet in the same direction as the planet moves
around the sun.
"But we are sseing just as many retrograde as prograde
irregular moons at
Saturn," Hergenrother said. Objects captured as moons would
move in either
prograde or retograde orbits depending on their direction as they
passed
through and were slowed by proto-Saturn's gas cloud.
Satellites in orbital clusters could range in size from one to
100
kilometers in diameter, he added.
"Right now, we see irregular satellites as small as 3
kilometers around
Saturn, but there may be many smaller than that. These may go on
a continuum
in size all the way down to the size of dust. "
[NOTE: Images supporting this release are available at
http://uanews.opi.arizona.edu/cgi-bin/WebObjects/UANews.woa/wa/SRStoryDetails?ArticleID=3904
]
==========
(2) SATURN'S DIRTY DOZEN
From Nature Science Update, 12 July 2001
http://www.nature.com/nsu/010712/010712-12.html
The new moons discovered orbiting Saturn are the remnants of
larger
ancestors.
JOHN WHITFIELD
Astronomers have discovered 12 more moons orbiting Saturn. This
brings the
planet's total to 30 - the highest in the Solar System.
Observations suggest
that 11 of the newcomers began life as three large moons, which
were
shattered by collisions1.
Four of the newcomers were unveiled last autumn; now, as well as
increasing
the tally, "we've tracked them and established their
orbits", says Brett
Gladman, of the Observatoire de la Côte d'Azur in Nice, France.
The moons -
most of which are only a few kilometres across - are moving in
loopy, tilted
orbits between 15 and 23 million kilometres from the planet.
Gladman and his colleagues used a network of telescopes in Chile,
Hawaii and
Arizona to scan the area around Saturn where the planet's
gravitational pull
exceeds that of the Sun : "We wallpapered the sky", he
says. Electronic
detectors mounted on the telescopes alerted the observers to the
moons.
The moons' irregular orbits suggest they were originally
wandering bodies
that were captured by Saturn's gravity, say the researchers. How
this came
about is a puzzle, says Carl Murray, an astronomer at Queen Mary
and
Westfield College, London, because "it's very difficult to
capture an
object".
For a wandering celestial object to be overcome by gravitational
attraction
and fall into step with another, it must first slow down.
Gladman's best
explanation is that Saturn's soon-to-be-moons were slowed by
passing through
the cloud of gas that surrounded the young planet about 4.5
billion years
ago, although other possibilities - that they bumped into
something else,
for example - cannot yet be ruled out.
Eleven of the satellites fall into three clusters with similar
orbits. The
researchers suspect that these are the remnants of three larger
moons that
were shattered into fragments by collisions with one of the many
comets that
pass through Saturn's neighbourhood.
One cluster includes Phoebe, Saturn's only previously known moon
with an
irregular orbit. Phoebe is the largest in the cluster; its
companions were
probably chipped off it by a glancing blow. If this is the case,
the probe
Cassini, which passes within an astronomical whisker of Phoebe in
the summer
of 2004, should see a crater bearing testimony to the impact.
Many small, irregular moons have been found orbiting the outer
planets in
the past few years and they could lead to a better understanding
of the
entire Solar System, including how the giant planets formed, says
Murray.
"It's like trying to find out your family history,"
says Murray. "If you
only look at the colourful characters, you miss a large part of
the
picture."
Saturn is unlikely to head the Solar System's lunar league table
for long.
The moon-hunters will turn their attention to Jupiter later in
the year,
where, Gladman predicts, "there are another dozen to three
dozen irregular
satellites waiting to be discovered".
References
Gladman, B. et al. Discovery of 12 satellites of Saturn
exhibiting orbital
clustering. Nature, 412, 163 - 166, (2001).
© Nature News Service / Macmillan Magazines Ltd 2001
==========
(3) SIZZLING COMETS CIRCLE A DYING STAR
From NASA Science News, 11 July 2001
http://science.nasa.gov/headlines/y2001/ast11jul_1.htm?list20392
Astronomers have detected a massive cloud of water vapor around
an aging
star. It could be the telltale sign of innumerable dying comets
and a
glimpse of things to come in our own solar system.
July 11, 2001 -- Stargazers here on Earth get excited whenever a
comet comes
close to the Sun. Comets -- icy visitors from the outer solar
system -- are
easily vaporized. Even a little sunlight will cause one to bubble
and froth,
dispensing a tail that stretches millions of kilometers through
space and
far across the night sky. Bright comets are unforgettable sights.
Now imagine a solar system in which not one but billions of
comets are
vaporizing -- all at the same time!
That's what astronomers may have found around an aging star
called
IRC+10216. "We see substantial concentrations of water vapor
around this
star," says Harvard's Gary Melnick, Principal Investigator
for the
Submillimeter Wave Astronomy Satellite (SWAS), the orbiting
observatory that
made the discovery. "The most plausible explanation for this
water vapor is
that it is being vaporized from the surfaces of orbiting comets
-- 'dirty
snowballs' that are composed primarily of water ice."
IRC+10216, also known as CW Leonis, was once a well-behaved
main-sequence
star as our own Sun is now. But the aging giant is substantially
heavier
than the Sun --as a young star it contained 1.5 to 4 solar
masses-- so it
evolved more quickly. About one billion years ago, say
astronomers,
IRC+10216 ran out of hydrogen fuel in its core. Since then hotter
fusion
reactions involving helium and carbon have replaced simple
hydrogen burning
-- swelling the star enormously. If IRC+10216 was located at the
center of
our solar system, it would engulf Mercury, Venus, Earth, Mars and
Jupiter.
"We think we are witnessing the type of apocalypse that will
ultimately
befall our own planetary system," says SWAS team member
David Neufeld,
professor of physics and astronomy at Johns Hopkins.
"Several billion years
from now, the Sun will become a giant star and its power output
will
increase five thousand fold. As the luminosity of the Sun
increases, a wave
of water vaporization will spread outwards through the solar
system,
starting with Earth's oceans and extending well beyond the orbit
of Neptune.
Icy bodies as large as Pluto will be mostly vaporized, leaving a
cinder of
hot rock."
From its vantage point in orbit above the absorbing haze of water
in Earth's
atmosphere, SWAS can detect distinctive radiation at
sub-millimeter
wavelengths emitted by water vapor in deep space. When
astronomers turned
the satellite toward IRC+10216 they discovered a substantial
cloud of water
vapor about 100 AU across. ("AU" --short for
Astronomical Unit-- is a unit
of length used by astronomers. One AU equals the mean distance
between Earth
and the Sun.)
"There must be about four Earth-masses of frozen water
around IRC+10216 to
produce the vapor cloud we see," says Melnick. The water
vapor probably does
not come from the vaporization of oceans on an Earth-like planet,
because
there wouldn't be enough water on such a planet to supply the
cloud.
Instead, the researchers speculate, the vapor cloud might come
from a swarm
of several hundred billion comets orbiting 75 AU to 300 AU from
the star.
That might sound like a lot of comets, but we know that such
swarms can
exist. For example, there is a great reservoir of dormant comets
right here
in our own solar system -- a doughnut-shaped cloud called the
Kuiper Belt.
The Kuiper Belt extends far beyond the orbit of Neptune and
harbors a vast
population of small icy bodies. Scientists think they are
primitive remnants
from the earliest days of our solar system, leftover bits and
pieces that
were never consumed by growing planets.
"In our own solar system, these [Kuiper Belt] comets orbit
the Sun quietly
for the most part," says Saavik Ford, a Johns Hopkins
graduate student who
contributed to the SWAS discovery. "Occasionally a comet
comes in close to
the Sun, starts to vaporize, and displays the characteristic coma
and tail
that we are familiar with. But IRC+10216 is so much more luminous
than the
Sun that comets start to vaporize even at the distance of the
Kuiper Belt.
So one has several hundred billion comets all vaporizing at
once."
In recent years planet-hunters have found more than 50 stars with
planets.
Most of those systems, which harbor very large planets close to
the central
star, don't seem to be much like our own solar system. However,
the
observations of water vapor around IRC+10216 suggest that some
stars might
indeed have planetary systems similar to our own, with an alien
Kuiper Belt
and abundant water. Water, of course, is a key ingredient for
life as we
know it -- and that's the most tantalizing prospect of all!
"This just goes to show that a star doesn't have to be
bright to be
interesting," says Neufeld. IRC+10216 is a dim 18th
magnitude star located
500 light years from Earth in the constellation Leo. "The
star seems so
faint because it is shrouded in its own cocoon of obscuring dust
and gas,"
he explains. "But at infrared and submillimeter wavelengths
it's one of the
brightest objects in the sky."
Indeed, if humans could see infrared light, IRC+10216 would be an
eye-catching beacon in the night sky. But in real life it's
practically
invisible. By piercing the star's veil of mystery, SWAS has
revealed what
astronomers long-suspected: there's much more to IRC+10216 than
meets the
eye.
=========
(4) THE ORIGIN OF SEX: COSMIC SOLUTION TO ANCIENT MYSTERY
From Space.com, 10 July 2001
http://space.com/scienceastronomy/solarsystem/origin_sex_010710.html
By Robert Roy Britt
Senior Science Writer
Comets and asteroids have been blamed for a lot of things before.
Shaping
Earth. Jumpstarting life. Wiping out dinosaurs. Even possibly
altering human
evolution.
But never sex.
Roughly 1 billion years after the first organisms romped in the
hay, the
origin of sex remains one of biology's greatest mysteries.
Scientists can't
say exactly why we do it, or what triggered those initial
terrestrial
flirtations. Before sex, life seemed to manage fine by employing
asexual
reproduction -- the cloning of offspring without the help of a
partner.
Now a new study out of Caltech and NASA's Jet Propulsion
Laboratory has used
digital organisms to simulate life before sex and yielded a
possible
mechanism for instigating Earth's first courtship.
Intimacy never sounded so stressful.
Comet or asteroid impacts could have stressed asexual organisms
enough to
send them down the path of sexual reproduction after forcing a
flurry of
genetic mutations, the study shows. Heavy doses of radiation
might also have
done the trick.
While these potential catalysts for mutations are highly
speculative,
researchers Claus Wilke and Chris Adami announced Monday night
that they
have determined with certainty one possible way that organisms
could have
managed such a chaotic environment to their advantage in opening
the
original door to sexual liberation.
The key to this mutation management, Adami told SPACE.com, is the
discovery
that when things get rough, a population of organisms adapts to
handling a
few mutations, while also ensuring that many mutations will be
self-destructive.
"Mutations can and do still occur," he said, "but
they lead to dead
organisms and therefore do not affect the future."
Before sex
Sex never should have happened, biologists often say.
Though the ultimate act of affection has been around longer than
anyone can
remember, it wasn't always so. On the early Earth, all organisms
reproduced
asexually.
Any gardener is familiar with how asexual production works.
Underground
runners can create multiple clones (not to mention destroy a good
lawn).
Potatoes give up an eye to create another potato. Bulbs divide.
Cacti,
exhibiting no creativity in this area but managing to foster
progeny
nonetheless, simply let pieces of themselves fall to the ground
and hope for
the best.
Some animals get in on the asexual act, too. Sponges and sea
anemones
produce little ones via buds. Flatworms, if cut in two, grow a
new head on
one of their severed ends and a new tail on the other.
These are handy and powerful ways to leave a legacy.
For one thing, there's no need for a partner -- no butting of
horns, no
beating of the chest, no late nights at the bar. Reproduction is
virtually
guaranteed. Also, when desirable traits evolve, they are not
quickly diluted
by evolution. Your offspring are just like you. Exact clones.
Sex, on the other hand, combines myriad mutations with each
pairing of
genes, and the process "can wash out the good and accumulate
the bad," Adami
says. Just ask any failed child of successful parents.
The age of sex
Despite all these advantages for asexual reproduction, somewhere
along the
evolutionary line sex became all the rage.
Thankfully so, for we humans owe our existence to that first
melding of the
genes. Asexual reproduction provides for a plodding style of
evolution,
relying solely on accidental mutations to effect change. It's an
evolutionary slow train that might never have gotten around to
delivering
humans. It can also limit a population's ability to survive
severe
environmental change.
Sex, on the other hand, allows plants and animals to evolve
quickly, because
the gene pool mixes and the fitter survive.
Yet as any parent knows, sex is a rather inefficient way to make
babies.
Biologically speaking, the man spends nine months doing
absolutely nothing
productive while the woman does all the work (in some households,
this
problem is known to persist far longer).
So in an evolutionary sense, why would sex ever have become so
popular? More
to the point, why would any asexual organism have bothered to try
out sex in
the first place?
We're all mutants
Researchers have long known that mutations rewrite portions of an
organism's
genetic code. Some mutations can be good, in fact helping a
species to
thrive at the expense of others. But the effect can sometimes be
deadly.
Since sex involves two parents, there is twice the number of
mutations to
muck up the genetic scripts.
Wilke and Adami created two different simple, computerized life
forms that
"share many characteristics with bacteria," then placed
them in a stressful
environment where the rate of mutations was high. By studying
digital
creatures, they were able to zip through many generations in a
short time.
The scientists found a natural throttle to the number of
mutations a
population of asexual bacteria can handle. The throttle can be
thought of as
a conservation law. The law dictates that a population capable of
adapting
to the harmful effects of a few mutations cannot possibly handle
a bunch of
mutations. Past a critical limit, the accumulated mutations make
gibberish
out of the genetic code and the organisms die.
Conversely, the new law also shows that a population which can
handle many
mutations would be highly vulnerable to the first few. "In
fact there are
such organisms [today]," Adami said. "Sex could,
however, never evolve" in
such a population. The offspring would be too vulnerable to the
initial
flurry of mutations that would be written into its code, combined
from two
organisms.
The birth of sex
Now imagine simple organisms long ago that just happened to share
genetic
information in a loose and uncoordinated fashion. Such sharing
goes on today
without leading to reproduction.
If such a population of organisms were suddenly faced with the
stress of
high mutation rates, it would over the course of many generations
develop a
capacity to handle a few mutations. But by the new law, numerous
mutations
would be intolerable.
The effect of all this, Adami says, is that bad mutations would
be weeded
out of the population.
When multiple mutations are intolerable, bad mutations cannot
accumulate,
because each successive bad mutation has an increasingly deadly
effect on an
already weakened organism. Useful mutations, however, do not harm
a
population in these conditions, Adami said.
Put another way: "When multiple mutations are intolerable,
bad mutations
cannot accumulate, while the good ones still can."
This could pave the way for the benefits of sex to be enjoyed.
A theoretical door would be open to sexual freedom, and if a pair
of
organisms mutated enough to go behind that door, then their
newfound ability
to share beneficial mutations, via sex, would give them a
Darwinian
advantage over their asexual cousins in the highly stressful
environment.
"You can imagine a path that leads from the uncorrelated
exchange of genetic
material to the completely orchestrated recombination
process," he says,
referring to the birth of sex.
Any number of catastrophes might have fueled a changed
environment and a
rate of high mutations, Adami explains. A cosmic impact could
have altered
Earth's atmosphere for millions of years, exposing the planet to
high doses
of radiation. Increased volcanic activity is another possible
source.
But Adami stressed that these possibilities, while useful to
consider, were
not a part of the study and so remain highly speculative.
Not actually living organisms
Clifford W. Zeyl, who studies evolutionary genetics at Wake
Forest
University, called the work surprising and interesting, but added
a further
caution:
"Since the idea came from a study of digital organisms and
not from any
historical evidence that such stresses actually acted on living
organisms,
or that they would have had the effect of selecting for sex, I
think it's
highly speculative," Zeyl said.
Adami is confident that the computer experiment renders an
accurate picture,
and he suspects that if such a test could be carried out on real
organisms
(it can't, because it would take too long) similar results might
be found.
"The digital organisms actually live in the memory of the
computer, so all
we do is set up the experiment and then observe," he said.
He added that
some biologists are skeptical of any research carried out using
digital
organisms, but says there is "no reason whatsoever" to
think that the
findings would not apply in real-life situations.
The study results are published in the July 22 issue of the Royal
Society
journal Proceedings: Biological Sciences B.
Copyright 2001, Space.com
==========
(5) A PIECE OF HEAVENS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
From The Hamilton Spectator, 3 July 2001
http://www.hamiltonspectator.com/news/435248.html
A piece of the heavens: Couple sky-high after finding meteorite
By Kate Barlow, The Hamilton Spectator
kbarlow@hamiltonspectator,
905-526-3408
Joseph Mahe was busy clearing his fields of stones forced to the
surface
during the spring thaw when he came upon a large, rust-coloured
rock.
His first thought, that morning in 1999, was of the damage it
could do to
his farm machinery.
"But when I got hold of it, it was much heavier than an
ordinary rock," the
farmer recalls. "I thought this is something
different."
Joseph and his wife Marcelle often came across interesting rocks,
enough
that Joseph has earned the nickname Fred -- as in Flintstone. In
the 34
years on their Hagersville farm, they have uncovered arrowheads
and fossils
by the score. But never anything like this.
Joseph tossed the strangely heavy rock onto his tractor, finished
his stone
clearing and returned to the barn where he called a neighbour.
They took a hammer to the rock. It bounced off. The rock made a
dull
metallic sound.
The two hit it again, and again. Eventually, metal showed through
the
surface. Perhaps it was a piece of farm machinery from years
past. The
neighbour joked that Christopher Columbus must have dropped it
when he
passed by.
But Marcelle, on her return from grocery shopping, declared,
"That's a
meteorite!"
The previous winter, Marcelle had read a book on the minerals of
her home
region of Brittany, France. One of the illustrations of a
meteorite looked
just like the rock her husband and neighbour were puzzling over.
"Let's just
say they were skeptical," says Marcelle tactfully of the
men's reaction.
But they couldn't come up with a better theory, so they sought
advice from a
relative who had been a mineral collector since boyhood. He felt
the chances
that it was some kind of meteorite were high enough to consult an
expert.
The family arranged to take the 30-kilogram specimen to the 1999
Rockhound
Gemboree, Canada's largest mineral and gem show, held every
August in
Bancroft. They will never forget the excited expression on
Richard Herd's
face, as the curator of Canada's National Meteorite Collection
bent to
examine the Mahes' rock.
He didn't give them a definitive answer, but said he felt it
could be a
meteorite and that he would make arrangements to have it tested.
"We were
all pretty excited," says daughter Michelle Holmes.
"You can go to a
(mineral) show and buy them, but how often can you say I found a
meteorite?"
Before Herd actually saw the Mahes' find, he was skeptical. Many
people
approach him with a rock they believe is a meteorite. "Nine
hundred and
ninety-nine times out of 1,000, it's not," he says.
"But when I tried to
lift (the Mahes' find), I thought, it's entirely possible it is
one. It
looked good, the colour looked good and it was magnetic."
He got permission from the Mahes to take the rock back to Ottawa
where it
was photographed and a small piece removed before it was returned
to them
the following year. Steve Kissin, a geology professor at Thunder
Bay's
Lakehead University, learned of the Hagersville meteorite in the
fall of
1999 at a meeting of the Canadian Space Agency's Meteorites and
Impacts
Advisory Committee and
was later sent two small slices cut from the rock.
Kissin's first task was to wash the pieces with an acid solution
so that,
when viewed under a specially designed microscope, he could
detect kamacite
and taenite, two forms of iron present in meteorites but rare on
earth. The
acid test of authenticity was spotting tiny crystals known as
Schreibersite. Their distinctive structure and pattern proved
beyond doubt
that the slices of metal were from outer space. Kissin also
observed bands
called Neumann lines, indicative of the cosmic shock following a
collision
by the meteorite's parent body.
"That's not something found in terrestrial rocks, but which
is quite common
in meteorites," said Kissen.
The professor's final test, before the samples were dispatched
south to
Activation Laboratories of Ancaster for detailed analysis, was to
measure
the hardness of the metal to determine the degree of cosmic shock
and
prepare two "standards" to measure the Hagersville
samples against, one of
steel and another from a well-known meteorite.
Activation Laboratories has laboratories in the United States and
South
America and customers in 60 countries. It has a worldwide
reputation for
chemical, physical and metallurgical analysis of everything from
meteorites
and mining exploration samples to fire debris and failure
analysis for the
aircraft and automobile industries.
The company's client list reads like a Who's Who of the global
mining
community. It has helped discover copper in Chile, diamonds in
the Northwest
Territories and gold in Mexico. Its labs can take a leaf from a
tree and
tell you what's in the ground below. Its patented technology can
analyse a
soil sample and detect what lies 400 metres below the surface.
"We're leaders in the world in fine analysis," says
company founder and
owner Eric Hoffman.
A meteorite sample is placed first in a plastic capsule and made
radioactive
in McMaster University's nuclear reactor before returning to the
company's
laboratories for what's called instrumental neutron activation
analysis.
This involves placing the sample in what's called a germanium
detector --
resembling a large barbecue propane tank -- which measures the
presence and
quantity of 13 different minerals. The proportion of those
elements will
determine the kind of meteorite. The sample is then disposed of
at Canada's
nuclear laboratories at Chalk River.
Once the Ancaster analysis was completed, the results were sent
to Kissin.
He decides whether a meteorite is a new find, part of another
meteorite, or
one that has been transported from its original site.
After completing his analysis, Kissin must submit his results and
the
proposed name to that august body, The Meteoritical Society,
formed in 1933
to promote the study of extraterrestrial materials and their
history.
The Mahes haven't decided what they will do with their meteorite
-- sell it,
donate it to the national rock collection or keep it as a
keepsake. The
value of a meteorite depends on how unusual it is, but starts at
$1 a gram.
For now it is kept under lock and key in a safe place, far from
the farm
where it lay, perhaps since the world was young. "This is
out of this
world," says Marcelle.
* The Meteoritical Society
http://www.uark.edu/campus-resources/metsoc/home.htm
IMAGE CAPTION:
Marcelle and Joseph Mahe of Hagersville show off their
30-kilogram meteorite
found on their farm. Photo: Kaz Novak, the Hamilton Spectator
Copyright © 2001 The Hamilton Spectator. All rights reserved.
===========
(6) THE MOON AND PLATE TECTONICS: WHY WE ARE ALONE
From SpaceDaily, 11 July 2001
http://www.spacedaily.com/news/life-01x1.html
Without plate tectonics, new mountain belts could not form. Earth
would be a
Waterworld with occasional shield volcanoes emerging briefly
above the
waves. If regular catastrophic convective overturn occurred, as
on Venus,
life would have a precarious foothold indeed.
by Nick Hoffman
Sydney - July 11, 2001
The existence of a large Moon in orbit around the Earth and its
implications
for the origin and nature of life have been a subject of
considerable
discussion. With the Hartmann/Davis models for the catastrophic
origin of
the Moon by glancing collision, it has become clear that our Moon
is a rare
celestial object and that few Earth-like planets could have
produced such a
chance outcome during their assembly.
If, therefore, aspects of the Moon's existence strongly impact on
the origin
and development of life, then we may be able to explain why life
(as we know
it) might be rare in the Universe.
The bulk of arguments about the Moon relate to its effect on the
orbital
dynamics of the Earth-Moon system (which is stabilised against
spin-axis
inclination variations, unlike Mars), and to the tidal influence
on
ecosystems (developing broad coastal flats with regular currents,
water-depth variations, and monthly cycles).
None of these are compelling arguments for the origin or nature
of life.
Instead, we look here at plate tectonics as an essential engine
for
maintaining the continent/ocean duality on Earth, which enabled
advanced
life to emerge on land and develop to a tool-using
electro-mechanical
civilisation (our definition of "advanced life"?).
Others have speculated that the heat pulse due to the
Lunar-originating
impact was the trigger to start plate tectonics but we show that
this is a
minor effect of timing. Instead, the enabling factor is the
removal of ~70%
of the primordial crust of the Earth to a position in orbit
400,000 km
overhead. If that crust were returned and replaced on Earth it
would fill
the ocean basins with wall-to-wall continent. This would choke
plate
tectonics, as on Venus, and displace the oceans to flood the land
to a depth
of several km.
Without plate tectonics, new mountain belts could not form. Earth
would be a
Waterworld with occasional shield volcanoes emerging briefly
above the
waves. If regular catastrophic convective overturn occurred, as
on Venus,
life would have a precarious foothold indeed. There may be many
habitable
worlds, but they are likely to be Waterworlds where swimming or
flying
creatures might evolve significant intelligence, but would be
unlikely to
progress to discover fire, electricity, computers, radio, and
rockets.
The Origin of the Moon
During the last decade, the science community has rallied
squarely in favour
of a catastrophic origin model for the Moon. Late in the Earth's
accretion a
large body of perhaps Mars size hit the Earth (then about 60%
complete, and
already with a differentiated core, mantle and crust). This in
itself was
not unusual. Most of the planets show signs of large late impacts
in their
eccentric orbits and tilted spin axes, but this one was something
special.
The impact was at just the right angle to almost bounce off, but
to be
captured and swallowed by the Earth. The highly oblique impact
struck a
glancing blow to the Earth's surface and set up giant shock waves
that
spalled material into space. The surface of the Earth was heated
and may
have begun to boil --not just the Oceans, but the rock itself!
The debris that was spalled off, and the boiling clouds of rock
gas formed a
ring around the proto-Earth and then condensed into one or more
glowing
clumps of molten material that finally amalgamated into a giant
Moon. When
the dust settled, the nature of the Earth had been changed
forever some
60-70% of its primordial crust had been blasted off into space. A
giant
glowing ball reared overhead, perhaps ten times closer than the
Moon is
today (and ten times larger, visually). Giant tides would have
been raised
of over one kilometre in height in the oceans that condensed back
onto the
Earth, and of several tens of metres in solid rock!
The heat produced by these tides absorbed energy from the spin of
the Earth,
and some was transmitted by tides (gravity gradients) to the Moon
itself,
pushing it further away from the Earth. Gradually the tides
lessened and the
surface of the Earth stabilised, while the Moon cooled and
settled into a
slower, steadier orbit. Accretion was still continuing, mopping
up the last
debris of the Solar System, and soon the giant scars of the
formation
process were concealed by new impacts.
Of key importance for the Earth, it had gained extra core
material from the
dense centre of the impactor, but it had lost a large amount of
its crust.
That crust is now in orbit nearly 400,000 km over our heads - a
very strange
place for a planet to keep its crust. The consequences for the
Earth, and
life on it, have been profound. It is no exaggeration to say that
without
the Moon, there would be no civilised life on Earth. In fact,
there would
probably be very little land on Earth, as we shall see...
Earth - the divided planet
Our planet seems familiar to us, and we accept as commonplace its
gross
structure and how it works. Although it took until the 1970's for
plate
tectonics to be accepted fully by the scientific community, that
model for
the way that all processes on Earth are geared together, and for
how
mountains are built and rebuilt over time seems totally normal to
us today.
We even accept without comment that we actually have continents
and Oceans
as distinct entities, but no other planet or Moon in our Solar
System is
organised like this. No other planet has plate tectonics.
Some authors suggest that plate tectonics was enabled by the heat
pulse of
the Moon impact, but once the first billion years have passed,
events like
that are irrelevant thermally. What is important is why plate
tectonics
continues, despite the lack of such a thermal pulse. To
understand this we
need to look again at the Moon, the Oceans, and the Continents.
One common misconception about the Moon is that it was somehow
spat out of
the Earth, and the Pacific Ocean marks the scar of its birth. We
know this
is dynamically impossible, and anyway the Pacific Ocean is far
too young
(<180 Ma) to be the birth scar of the 3.8Ga Moon (and that's
just a surface
age, the Moon-forming event probably occurred at ~ 4.45Ga).
However, we can
make use of this concept. Let's take the Moon, which is after,
all, the
primordial crust of the Earth. Let's tear it up into pieces like
a giant
ball of modelling clay, and flatten out those pieces into broad
flat plates
about 40 km thick - In short, let's form the Moon back into
crust, and put
it back on Earth.
Today, the Earth is about 70% ocean and 30% land. If we replace
the missing
70% of crust, then we will entirely fill the ocean basins. The
water will be
displaced and will flood out over the land. If we do this to the
modern
Earth, only a few decent areas of land remain from the 3 km deep
flood. All
of Australia is gone. The Himalayas and the Andes are some of the
few
remaining "continents", and Iceland of course survives
because it is such a
profuse volcanic centre. Everything else is just a tiny pimple of
a mountain
(usually volcanic) adrift in a planetary ocean.
Even this is an overestimate of the land area. Those major
"continents" are
all intimately related to plate tectonics. They are either young
active
mountain belts, or intense volcanic centres built high on the
spine of the
mid-ocean ridge system. How would these fare on the remodelled
Earth?
The secret of plate tectonics is that the Earth has gaps betwwen
the
continents, and so they can move around like a sliding block
puzzle. But if
we replace the missing crust, there are no longer any spaces to
slide into.
Although tectonic forces might tug and squeeze, all they can do
is make a
few wrinkles here an there. That's what happens on Venus, where
the crust is
planetwide and ~30km thick everywhere. On Venus nothing can rift,
or spread,
or subduct, or collide, because there's already something there
blocking the
way.
If we restored the Moon to the Earth, we would block up plate
tectonics. The
planet would have to find other ways of losing heat - like the
profuse
volcanism of Venus, or the massive stacked volcanoes of Mars.
Plate
tectonics would stop. (Or would have never started). The oceans
would flood
the land, and any mountain belts would be worn away in a few
hundred million
years. Soon, there would be nothing left but a ball of water,
with just an
occasional volcanic island poking through the spindrift.
The Earth is not unique because if its oceans. Any planet in the
right part
of the habitable zone will have those. What is unique about the
Earth is
that it has LAND. If the moon had not carried away most of the
crust, there
would be no ocean basins, no land, and no chance for life to
evolve on land.
Venus - What the Earth would have been like
Although Venus is dry, and smothered in a suffocating atmosphere,
this is
merely a consequence of it being too close to the Sun. Were it
further away,
say where our Earth is now, then it would have a mild climate
with oceans
and rain, and probably also have a thin Nitrogen/Oxygen
atmosphere, and life
frolicking in its oceans.
Over 80% of Venus lies within 1 km of the mean radius of 6051.84
km. If
Venus had been further from the Sun and avoided the runaway
greenhouse
outcome, then it would have a hydrosphere like the Earth:- a mean
global
ocean of some 3 km. If we were to take the modern topography of
Venus and
flood it to an average depth of 3km, we would innundate nearly
90% of the
surface.
Perhaps this is what Earth would have been like if the Moon had
not been
formed? Even this is an overestimate of the amount of land.
Venus' surface
is almost uniformly 500 Ma in age and has not experienced
significant
rifting or mountain building in that time. Erosion on Venus is
very slow in
the hot dry atmosphere but on a waterworld erosion would be at
least as
rapid as on Earth. Planet girdling storms would smash on the
exposed shores
of any island, and rainfall would stream from the heavens.
Australia as a continent is a similar age to Venus' surface. We
no longer
have any topography more than 3km above the surface of the
continent, and
almost all of it less than 2 km, so the continents of Venus would
likely
have foundered below the waves long ago, if it were further from
the Sun.
Now perhaps every 500 to 1000 million years, the planet would
undergo an
upheaval and build new continents and new mountains, but anything
that
evolved to crawl onto land would be racing against time before
the land was
swallowed up again
Mars - How to escape a waterworld?
Mars has, in fact, escaped this fate because it is too far from
the Sun and
all its water is perpetually frozen. It hasn't rained on Mars for
at nearly
4 billion Years. The planet is so cold that its surface is
dominated by
processes driven by CO2. We find dry ice at the polecaps, CO2
vapour in the
atmosphere, and in the subsurface there will be both CO2
permafrost and
pockets of liquid CO2 (Hoffman 2001a, b, c). In the past, this
liquid CO2
occasionally burst out from underground and exploded into giant
rockstorms
that rushed down valleys, supported on a boiling cushion of CO2
Gas (Hoffman
1999).
Fascinating as this is, we are interested not in how Mars really
is, but how
it might have been if it were closer to the Sun. Then, the
mythical ocean of
the "Blue Mars" theorists would have become a reality.
How would Mars have
evolved?
We can flood modern Mars, of course, and see what happens. With a
smaller
planet like Mars, there is less water to flood the surface - an
equivalent
depth of half that on Earth seems likely, so we only have to add
1,500
metres of water to the planet. Finally we get a planet that has
significant
areas of land. With the lesser gravity of Mars, much taller
mountains are
possible. Surely they will resist erosion?
However, things aren't as simple - they never are! Mars has no
plate
tectonics, and does not even have the episodic mountain building
processes
that Venus does. Those attractively large looking land areas will
be
swallowed fast. Most of the mountains in the southern hemisphere
of Mars are
over 3.5 billion years old. They would all be gone by now. Even
the
dramatic-looking Tharsis volcanic province is deceptive. The flow
rate from
Mons Olympus is no more than from Hawaii on Earth. Erosion can
keep close
match to that leading to a broad shallow sea of eroded lava sand,
with a
small volcanic island in the middle.
And when we look at Mars' heat flow and the activity of its
volcanoes, we
find that the planet is cooling off and contracting (Hoffman
2001d). For the
last billion years, very little has happened on Mars to build
mountains. If
there were an ocean on Mars, it would have eaten away all the
land by now
and filled in the basins to make a giant flat ball covered in
water -
another waterworld.
Gigantism as an escape route?
We have seen that smaller planets than Earth fail because their
tectonic
engines cool off, and mountain building stops even though they
have less
ocean to flood the land. What about a larger, more active planet?
The trouble here is that with a larger planet, gravity is larger
so
mountains are unable to grow so high. (the strength of the crust
is a
genuine limit to the height that mountains can grow - only where
immense
tectonic forces squeeze entire continents together can we build
mountain
chains like the Himalayas. So on a larger world, mountains are
lower and
streams more erosive because of the stronger gravity.
At the same time, there is proportionally more water to flood the
land. And
proportionally more "continental" crust to float to the
top of the planet
and clog up plate tectonics. So it seems that gigantism leads to
worse
problems, not better.
Conclusion
There really seems to be no way to build a truly Earth-like
planet that
still retains its original inventory of light
"continental" crust. Big
worlds flood too deep and wear away the land. Small worlds cool
off and lose
their tectonic vigour, and then the land gets worn away even
though the seas
are shallower. Perhaps a very small world might have so little
ocean that
some land would survive, but worlds so small are prone to lose
their
atmospheres.
The process that formed the Moon out of Earth's primordial crust
has enabled
a very odd planet to exist - one that has Continents and Oceans,
Land and
Sea. It is only on such a planet that life can emerge onto land,
and evolve
to tool-using fire-burning , mechanical civilisation.
Around countless stars in our galaxy, and innumerable galaxies
through space
there will surely be Terrestrial planets, yet they will not be
Earth-like.
They will not have glistening Silver Moons orbiting silently
through space
around them, but only small dull rocks whizzing in orbit. The
worlds will
be, almost without exception, waterworlds.
Yes, they may have intelligent life in their seas, such as fish,
squid or
crustaceans. There may even be air-breathing creatures akin to
dolphins and
whales. There may be birds in the skies, but these creatures will
never
discover electricity, or computers, or rockets, or radio
telescopes.
The heavens are likely full of glorious ecosystems on delightful
planets,
but not one of them has the potential to launch an enquiry into
space and
ask "Where are They?", still less an actual mission to
another star.
If we humans can solve our problems on Earth and do develop into
a
starfaring civilisation, the Universe may be a lonely place for
the likes of
us, and perhaps we may find it our role to bring fire from the
gods, as
Prometheus was said to have done in our own prehistory.
The philosophy of living in a Universe such as this is an
interesting topic
to contemplate - and all because of our Moon!
Copyright 2001, SpaceDaily
=============
(7) BEATLES, WILSON & SPRINGSTEEN ARE STARS IN THE SKY, TOO
From Yahoo! News, 10 July 2001
http://dailynews.yahoo.com/h/lc/20010710/en/beatles_wilson_springsteen_are_stars_in_the_sky_too_1.html
(7/10/01, 6 p.m. ET) -- The Beatles, Brian Wilson, and Bruce
Springsteen are
among the brightest stars in the music world, and now they're
"stars" in the
sky as well. Last week, the International Astronomical Union--the
recognized
authority for the naming of celestial bodies--assigned the names
of those
legendary musicians, as well as famed record producer Phil
Spector, to a
group of recently discovered asteroids.
The names of asteroids are traditionally reserved for Greek gods,
goddesses,
and other mythological figures, but astronomer Ian Griffin, who
discovered
the Springsteen asteroid from Auckland, New Zealand, said,
"It's a case of
honoring the people who inspired our generation. It's no
different than
earlier astronomers naming one after Bach." Of his name
choice, Griffin
documented, "Bruce Springsteen (b. 1949) is a singer and
songwriter whose
music has provided a social commentary upon
late-twentieth-century America.
On the night this minor planet was discovered, his music
entertained the
observers."
Astronomer J. Broughton of Reedy Creek Observatory in Maryland
discovered
the asteroid now named Beatles, and he wrote in documenting his
name choice:
"The great 1960s British popular rock group from Liverpool
comprised John
Lennon, Paul McCartney, George Harrison, and Ringo Starr. They
are
unequalled in the rock era as prolific songwriters and innovative
recording
artists with George Martin."
Of asteroid Brianwilson, which Broughton also discovered, he
documented:
"Californian songwriter and record producer Brian Wilson (b.
1942)
contributed to 1960s pop culture, with songs like 'Fun, Fun, Fun'
exemplifying the pastimes of modern teenage life through the
Beach Boys' pop
group harmonies, giving out very good vibrations indeed."
Broughton also found the asteroid now called Spector, and the
astronomer
wrote: "New York-born record producer and songwriter Phil
Spector (b. 1940),
who at 18 recorded his first hit song and by 1964 had produced 20
hits like
the superb 'Be My Baby,' performed by the Ronettes. He broke new
ground with
his 'wall-of-sound' techniques."
Several asteroids, or "minor planets," were previously
named for Elvis
Presley, Jerry Garcia, Eric Clapton, and Frank Zappa.
-- Sue Falco, New York
Copyright 2001, Yahoo!
============================
* LETTERS TO THE MODERATOR *
============================
(8) UK UPDATE ON NEO ACTIVITIES
From Duncan Steel <D.I.Steel@salford.ac.uk>
Dear Benny,
In CCNet (CCNet 85/2001 - 10 July 2001) Andy Smith asked:
"We also want to request a CCNet update, from the UK team.
Are there
any encouraging developments?"
I do not know what counts as being "encouraging";
certainly there is nothing
startling to note. There may well be other points that I have
missed, but so
far as I am aware the current and near-term situation regarding
official UK
consideration of the NEO impact hazard and its amelioration is as
follows:
Present: PPARC review underway of the UK telescopes that might be
employed to some extent for NEO work (i.e., the observatories in
which the UK is a partner in the Canary Islands, Australia
and Hawaii, plus other related facilities). This would inform the
next
step:
October: Announcement expected from the UK Government regarding
the
steps to be taken to implement some or all of the
recommendations of the Task Force on Potentially
Hazardous Near Earth Objects.
The latter action, of course, may well be delayed. Following the
planned
chronology, however:
October 3-5: ESA-sponsored meeting on natural disaster mitagation
through
space-related techniques, to be held at Armagh
Observatory.
November: European science ministers' meeting to be held in
Edinburgh,
with the NEO impact hazard likely to be on the agenda.
December 14: Royal Astronomical Society specialist discussion
meeting (in
London) on the topic "Near-Earth Objects: An opportunity
for all UK astronomy and space science", to be organised by
Duncan Steel and Mark Bailey.
Duncan Steel
=========
(9) MORE PUZZLES ABOUT MARTIAN METEORITES
From John Michael Williams <jwill@AstraGate.net>
Hello.
There was a response by Tom Van Flandern <tomvf@metaresearch.org>
among many
others, suggesting a possible common origin of rock on Mars and
in what have
been called "Martian meteorites", caused by an ancient
collision or
explosion of some kind. If we are to accept the isotopic
inferences pointing
to the region of Mars, this has to be the explanation.
First of all, I think the extrapolations from chemistry and
traces of this
and that in the rocks are a bit over-done. The precision of many
of the
opinions, pro and con, drawn from these rocks sometimes exceeds
credibility.
For example, how can water erosion, which is a term describing
stratigraphy
and geological formations be applied to a single fragment of
rock?
Second of all, the Pathfinder robotic expedition landed in what
seemed to be
an ancient flood plain and found NO TRACE of any rock matching
the
minerology of any of the so-called Martian meteorites. The
similarity to
Martian rock therefore seems to hold only for the older data from
the Viking
mission, which had limited minerological capability but could
perform
isotopic analysis on scoops of stuff. In my opinon, Pathfinder
eliminated
most of the chances that the Martian meteorites were from Mars.
Isotopic
ratios can be created by diffusion on a concentration gradient in
any
proportion: Geological context, which is lacking for single
rocks, is
required to interpret isotopic ratios. But, this is just an
opinion.
What I can offer more than an opinion, are some calculations
posted at
http://publish.aps.org/eprint/gateway/eplist/aps1999jun25_002
These are based on fairly elementary, but not necessarily
intuitively
obvious, physics. They
prove that no rock can be ejected intact BY ANY ONE IMPACT at
over 2/3 the
speed of sound
in the rock. The physical characteristics of the context are
irrelevant;
only the speed of
sound in the ejectum matters.
Mars has too strong a gravitational field at its surface to
permit intact
ejection at escape speed of any known rock. This is before
factoring in the
fairly high vacuum called an "atmosphere" on Mars. This
tenuous atmosphere
does have a significant effect at speeds of several km/s.
So, I think it is physically impossible for the "Martian
meteorites" to have
been ejected by impact from Mars; if they are from Mars, some
other
mechanism than impact ejection must have been responsible.
Also, they don't seem to match rocks on Mars, so where else might
they have
been formed?
--
John
jwill@AstraGate.net
John Michael Williams
==============
(10) ROCKS FROM MARS: SHALLOW IMPACTS CAN DO THE TRICK
From James Marple <jesl@carolina.net>
Benny
Re the comment of H. Jay Melosh, UA:
He states the main ingredient for comprehension of how
'unshocked' rock
could be ejected from a planet but doesn't finish up by pointing
out that if
an impacting object penetrates the surface at a very shallow
angle to some
depth before exploding (and I know of such occasions on Earth)
then it could
loft large masses upward with some of the unshocked surface rocks
being
accelerated to ejection speeds.
Re the comment of Marco Langbroek " a surprising number of
them show only
weak evidence for shock." - This would of course reflect
their proximity to
the explosion. Those 'insulated' by 75 meters of rock would show
little if
any effect of shock. While Mr Langbroek feels "that we
probably still
understand very little of impact phenomena" I believe he may
have too little
appreciation of the value of common sense in observing large
impacts without
the tunnel vision that specialized training may instill. Of
course we need
to continue learning about the precise mechanisms but we
certainly
understand that a bullet fired into the ground at a shallow angle
could loft
an ant into low orbit undamaged.
James Marple
===========
(11) L'ENIGME VOLCANIQUE
From Hermann Burchard <burchar@mail.math.okstate.edu>
Dear Benny,
an article, or articles, under the title " L'énigme
volcanique" at
http://www.sciencesetavenir.com/vivre/page98.html
http://www.sciencesetavenir.com/vivre/page99.html
(in French, my apologies) contain many interesting details of
geology and
geological theory of the Azores (as far as my less-than-fluent
French
permits me to grasp).
I stumbled onto this when sampling science goodies frequently
found at:
http://quotidien.sciencesetavenir.com/
The articles seem to harmonize well with recent notes on CCNet
(mine)
concerning the Azores, other hotspots, hotspot tracks, origins of
the
Atlantic, etc. To be sure, no mention of comets or
asteroids is made by the
French geologists who are being quoted. But still, maybe
the timing
is no coincidence and perhaps these articles reflect the fact
that CCNet is
being noticed by geologists, with its offering of timely bits and
pieces
toward a NEW GEOLOGY based on the insights of neocatastrophism,
where the
eons, eras, and ages are marked off by impacts of meteoroids,
comets, and
asteroids.
On a related matter, as CCNet reported recently, work on CO2
emissions from
flood basalts was done independently by Tanner and Wignall (June
29 and July
10, communicated by Andrew Yee). Conflicting conclusions
were reached by
the two geologists. While Tanner found that CO2 emmissions of the
CAMP
basalt eruptions timed to the Tr/J extinction boundary had no
measurable
effect on the atmosphere, according to Wignall:
"The Permian extinction, for example, which happened 250
million
years ago, is marked by floods of volcanic rock in Siberia that
cover an area roughly the size of western Europe. Those volcanoes
are
thought to have pumped out about 10 gigatonnes of carbon as
carbon
dioxide. The global warming that followed wiped out 80 per cent
of all
marine genera at the time, and it took 5 million years for the
planet to
recover." ... "Wignall thinks that older volcanoes had
more killing
power because more recent life forms were better adapted to
dealing
with increased levels of CO2."
These strikingly divergent interpretations by two academic
geologists
suggest that revolutions may be to come yet within the strata of
that
science.
Regards,
Hermann
===========
(12) MOON HOAX
From Phil Plait <badastro@badastronomy.com>
Benny--
Just a note: I read Dr. Genge's article about the Moon Hoax
(CCNet 85/2001 -
10 July 2001) with some amusement. I have been embroiled in this
teapot
tempest since I first heard that Fox television would be airing
an hour long
"documentary" about it. The program was full of bad
reasoning, worse physics
and horrifying accusations. I put together a webpage debunking
the program
at http://www.badastronomy.com/bad/tv/foxapollo.html;
the page might amuse
(or infuriate) CCNet readers. I have also compiled a list of
links to
webpages on both sides of this issue; that list can be found
linked from the
above page. Traffic has died off somewhat since the show aired,
but I have
heard that Fox will rebroadcast it sometime this summer, and it
has already
been aired in the UK. We haven't seen the last of this
ridiculousness.
Thanks,
Phil Plait
* * *
* * The Bad
Astronomer *
* * *
Phil
Plait
badastro@badastronomy.com
The Bad Astronomy Web Page: http://www.badastronomy.com
==============
(13) SHOCK, HORROR: ACC DOESN'T BELIEVE MOON HOAX EITHER
From Sir Arthur C Clarke
As a long-time admirer of the United States, I am appalled to
hear that a
recent poll suggests that 20% of Americans are ignorant fools: I
hope the
figure is grossly exaggerated, as no other term is strong enough
to describe
anyone who believes the Moon landings have been faked. If the
late unlamented Evil Empire was still around, I might have
suspected some
of being communist sympathisers attempting to discredit the one
achievement
for which the U.S.A. may be remembered a thousand years from now.
Remembering how quickly Watergate unravelled, how could any
sane person
imagine that a conspiracy involving *hundreds of thousands
of people over
more than a decade* would not have done the same? Ben Franklin
put it well:
`A secret known to three people can be kept - as long as two of
them are
dead.'
And how do these nitwits account for the fact that, for the last
thirty
years, the laser reflectors and radio sensors on the Moon have
been
transmitting terabytes of data back to Earth? Who do they think
put them
there - E.T.s?
But I can't waste any more time on lunatics: I am too busy
proving that
George Washington never existed, but was invented by the British
Disinformation Service to account for a certain minor
unpleasantness in the
Colonies.
Sincerely,
Arthur Clarke 11 Jul `01.
==============
(14) RE: QUESTIONS ABOUT CELESTIAL OBJECTS COLLIDING WITH THE
EARTH
From Bob Kobres <bkobres@uga.edu>
Re QUESTIONS ABOUT CELESTIAL OBJECTS COLLIDING WITH THE EARTH
(CCNet
07/10/01):
Though there are numerous crater-like features (Carolina Bays)
along the
Atlantic coastal plane of the United States from northern Florida
to
Maryland, the shallow depressions are not typical impact craters
and their
origin is still a matter of some debate. See:
http://abob.libs.uga.edu/bobk/cbaymenu.html
The chances are good, however, that some high-energy event was
involved with
the megafauna extinction at the Pleistocene to Holocene
transition and that
the Carolina Bays obtained their unusually regular shape due to
the event or
its aftermath. Personally, I favor a comet vector:
http://abob.libs.uga.edu/bobk/firewate.html
http://abob.libs.uga.edu/bobk/ccc/cc022598.html
http://abob.libs.uga.edu/bobk/comfever.html
There is though some recently published evidence for a supernova
event at
this time period:
http://abob.libs.uga.edu/bobk/nuclear.html
If this claim of evidence for neutron bombardment holds up to
duplication in
other labs then a comet or highly fragmented asteroid is not a
likely vector
unless there are aspects of impact phenomena that we have yet to
appreciate:
http://abob.libs.uga.edu/bobk/caseof.html
Later.
bobk
Bob Kobres
bkobres@uga.edu
http://abob.libs.uga.edu/bobk
706-542-0583
Main Library
University of Georgia
Athens, GA 30602
===================
(15) AND FINALLY, THE FULL MONICA: SOCIAL SCIENCE AT ITS BEST....
From Yahoo! News, 8 July 2001
http://dailynews.yahoo.com/h/ucmg/20010709/cm/the_full_monica_1.html
By Maggie Gallagher
Now that Madonna is boringly, happily married and middle-aged,
guess who is
emerging as the new darling, the pet subject, of the academic
elite?
Monica Lewinsky, that's who. A new academic volume by New York
University
Press, "Our Monica, Ourselves," features essays by a
variety of
"progressive" scholars and thinkers on such topics as
"Monica Dreyfus," "The
President's Penis" and "The Culture Wars of the 1960s
and the Assault on the
Presidency: The Meaning of the Clinton Impeachment," by Eli
Zaretsky, which
proffers the kind of breathless prose once reserved for Harlequin
romances:
"At the same time, both his need for public life and his
sometimes confused
explanations for his actions drew attention to his vulnerability.
Clinton's
enemies sensed his weakness, and it aroused them."
Now, HBO is running around the country taping interviews between
Monica and
top professors and students. Elaine Showalter, a chi-chi
professor of
English at Princeton, recently brought 23 of her own students to
the
mountaintop to earnestly engage Miss Lewinsky in a cultural
studies
debate.....
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