PLEASE NOTE:
*
CCNet 146/2002 - 18 December 2002
--------------------------------
"If mankind is to explore the solar system and beyond on a
realistic
budget some lateral thinking is urgently needed. The first step
is to
abandon sending people into space. Once astronauts are left out
of
the equation, the cost-effectiveness goes up enormously. Though
unmanned probes lack the glamour associated with space
spectaculars like the
Apollo moon landings, they offer the best hope for studying the
planets
and, perhaps one day, the stars."
--Paul Davies
(1) TECHNOLOGICAL PROGRESS AND THE FUTURE OF SPACE EXPLORATION
Paul Davies <pcwd@ozemail.com.au>
(2) CAN MICROBES RAIN DOWN FROM SPACE? MORE SUPPORT FOR
CONTROVERSIAL THEORY
Space.com, 17 December 2002
(3) HYDROCARBON BUBBLES DISCOVERED IN METEORITE
New Scientist, 17 December 2002
(4) SCARS LEFT BY A SPACE ROCK CRATER: A METEORITE IMPACT IN
ARIZONA ABOUT
50,000 YEARS AGO LEFT A MARK THAT CHANGED THE LANDSCAPE AND
SCIENCE
Baltimore Sun, 16 December 2002
(5) ON THE EXISTENCE OF A PLANET X
Mario D Melita <m.d.melita@qmul.ac.uk>
(6) MIDDLE-EARTH IN THE SKY?
Govert Schilling <mail@govertschilling.nl>
(7) CATASTROPHIC DISRUPTION IN THE SOLAR SYSTEM
Patrick Michel <michel@obs-nice.fr>
(8) AND FINALLY: DARWIN IN THE CLASSROOM. OHIO ENCOURAGES
CRITICAL SCIENCE
EDUCATION
National Review, 17 December 2002
=========
(1) TECHNOLOGICAL PROGRESS AND THE FUTURE OF SPACE EXPLORATION
>From Paul Davies <pcwd@ozemail.com.au>
Dear Benny,
On reading Corole Rutland's article EXPLORING SPACE WILL REQUIRE
NEW ROBOTS
(CCNet, 17 Dec 2002), I wondered whether your readers might be
interested in
an article I wrote in the same vein in 1999 for the anniversary
of the first
moon landing. It was published in The Australian.
With best wishes,
Paul Davies
-------------
The Future of Space Exploration
When Neil Armstrong took that first small step for man in July
1969, it
appeared to many that mankind stood poised on the brink of a
magnificent new
era. The dream that human beings would one day spread beyond
planet Earth,
and venture deep into space, seemed on the point of being
fulfilled. Landing
on the moon demonstrated that manned space flight was possible.
The next
stop would be Mars. Before long even the stars would be within
our reach.
Naturally Hollywood had already prepared the way. Stan Kubrick's
epic movie
2001: A Space Odyssey helped foster the impression that massive
orbiting
space stations and lunar colonies were just around the corner,
while
interplanetary travel was but a few decades away. The
long-running saga Star
Trek cast Captain Kirk and his crew in the role of latter-day
pioneers
opening up the galaxy in the manner of the American West.
Thirty years on the grandiose vision of mankind going boldly to
the final
frontier somewhere beyond the Milky Way seems ludicrously wide of
the mark.
The euphoria that has accompanied NASA's modest success in
sending two small
unmanned craft to Mars illustrates starkly just how limited our
space-faring
achievements have been to date. We aren't going to colonise the
moon by
2001, or even by 2020.
This attenuated progress hasn't discouraged the dreamers,
however. Arthur C.
Clarke was author of the original 2001 story and has been the
acclaimed guru
of space exploration for a generation. Convinced that mankind's
destiny lies
among the stars, Clarke recently described how a planet like Mars
could be
artificially adapted - terraformed, to use the jargon - to permit
human
habitation. Meanwhile, American aerospace engineer Robert Zubrin
has just
published a bold plan, dubbed Mars Direct, to establish a
permanent human
presence on the red planet within a decade.
These musings are fun, but they don't square with reality. The
popular
conception of intrepid astronauts hopping from planet to planet
as routinely
as we now fly from city to city is a pipe-dream.
Over-riding all other obstacles to manned space flight is the
tyranny of
distance. Space is hugely, unimaginably vast. To put the moon
landings in
perspective it is helpful to think in terms of the speed of
light, a dizzy
one billion km per hour. Light takes about a second to traverse
the distance
to the moon, and some minutes to reach Mars. The solar system is
a few light
hours across.
Contrast this with interstellar distances. The nearest star, in
the
constellation of Centaurus, is over four light years away. Our
galaxy, the
Milky Way, is more than 100,000 light years across. Other
galaxies are
millions or even billions of light years away.
Distance as such is no problem if you have unlimited time. Our
existing
rockets could deliver a payload to nearby stars after a journey
of ten
thousand years, but recruiting astronauts would be a problem.
The obvious solution is to go faster. Unfortunately speed costs
money. To
double the speed means expending four times the energy. Actually
this
understates the problem because conventional rockets have to
accelerate the
residual fuel as well the payload. Fuel requirements soon
escalate to the
point of absurdity. The familiar science fiction scenario of a
rocket ship
blasting off from the nearest spaceport and heading for the stars
on a tank
of high-octane gas is totally ridiculous.
Space travel pundits have long acknowledged this fundamental
limitation, and
many alternative ways to traverse the universe have been
suggested.
Proposals vary from enormous nuclear reactors, through antimatter
drives, to
vast sails that harness the tiny pressure of sunlight. Most of
these schemes
are too fanciful to be taken seriously.
Certainly there are ways to improve on simple rocketry, the most
practical
being the so-called gravitational assist method. A craft launched
from Earth
on a carefully chosen trajectory can be boosted by the motion of
the
planets. It is a technique already used by NASA to cut launch
costs. That is
why the Galileo spacecraft was sent to Jupiter via Venus.
Although the gravitational assistance of the big planets like
Jupiter and
Saturn can propel a spacecraft right out of the solar system, the
maximum
speed that is theoretically attainable is 100 km per second. Fast
though
this may seem, it would still take ten thousand years to reach
the nearest
star.
Most enthusiasts pin their hopes of interstellar travel on some
unspecified
"warp drive", yet to be discovered. But even here one
runs up against an
insuperable obstacle. According to Einstein's theory of
relativity, the
speed of light is the fastest speed in the universe. No
spacecraft can break
the light barrier, however powerful its motors may be.
There is a large amount of experimental evidence to support this
prediction.
Physicists routinely accelerate subatomic particles to very near
the speed
of light, and have confirmed that it is indeed a fundamental
limit. If you
try to make particles of matter go faster, they simply get
heavier instead.
The largest accelerator machines can propel protons with such
force that,
had Einstein been wrong, they would easily reach ten times the
speed of
light. But they consistently fail to break through the light
barrier.
Scientists are agreed that this is not just a technological
problem that may
be overcome one day, but a basic law of nature that can never be
violated.
The existence of an absolute speed limit demolishes a cherished
myth of many
science fiction writers - the galactic empire. In the early days
of the
British Empire, it took at most a few months to send back news or
dispatch
soldiers to a far-flung outpost. It would take tens of thousands
of years
simply to signal a colony on the other side of the galaxy.
A crafty method for evading this restriction was proposed by the
late
American astronomer Carl Sagan in his novel Contact, now the
subject of a
major feature film starring Jodie Foster.
Sagan's idea makes full use of the theory of relativity. Besides
imposing a
speed limit, Einstein's theory also predicts that space is curved
or warped
by gravity. Mostly this distortion of space is very slight. The
sun's
spacewarp, for example, bends passing starbeams by less than a
thousandth of
a degree. A black hole, on the other hand, curves space
ferociously. Its
gravitational field is so strong that it traps light completely.
If space can be bent back on itself far enough, it can reconnect
to form
what is known as a wormhole, an old idea among physicists dating
back to the
fifties. A wormhole resembles a black hole, except in one crucial
respect.
Fall into a black hole and you are on a one-way journey to
nowhere. A
wormhole, on the other hand, might form a tunnel connecting two
widely-separated locations, creating a shortcut. Just as drilling
a hole
through the Earth would cut the distance from Sydney to London,
so a
wormhole in space might put us within reach of the galactic
centre. In
Contact, Sagan's hero plunges through just such a wormhole and
crosses the
galaxy in minutes.
Amusingly, this fictional scenario triggered a spate of research
papers by
theoretical physicists, eager to check whether it could really be
done. Kip
Thorne and his co-workers at the California Institute of
Technology have
investigated mathematically whether stable wormholes in space
comply with
the equations of relativity.
Remarkably the basic idea holds up to scrutiny. However, it is
hardly a
practical proposition. In Contact, the wormhole is accessed from
Earth with
a machine that looks like a giant kitchen mixer. But that was
just a
fictional fudge. In reality, one would first need to capture a
body of many
solar masses and then configure its gravitational field
appropriately, using
matter with exotic properties never yet observed. The challenge
of actually
entering and transiting such a wormhole, even if one existed, has
scarcely
been considered.
Back in the real world, the options are much more limited. The
endless
problems afflicting the Mir space station show just how hard it
is for
humans to live and work efficiently in space. Scientifically, the
immense
effort involved in manning and equipping the space station
brings few
benefits. The Mir cosmonauts just go round and round, only a few
hundred
kilometres above our heads, and accomplish little of value. A
project like
Mir may be successful as a political gesture, but it is a very
inefficient
means of exploring the cosmos.
The best hope for manned flight in near space probably comes from
the
attempt to commercialise it. A British company just started
selling seats
for brief 'space lobs' in five years time. Millionaires may even
be prepared
to pay for a few days in an orbiting hotel. And in the unlikely
event that
some money-spinning industrial process could be done only in
space, big
business might foot the bill.
The bulk of the space program, however, will inevitably remain
funded out of
the public purse. NASA and its European counterpart ESA are
desperate to
trim costs. The Shuttle, which soaks up the lion's share of the
US budget,
may be successful as a sky truck, but it is designed for low
Earth orbit,
not deep space missions. If mankind is to explore the solar
system and
beyond on a realistic budget some lateral thinking is urgently
needed.
The first step is to abandon sending people into space. Once
astronauts are
left out of the equation, the cost-effectiveness goes up
enormously. Though
unmanned probes lack the glamour associated with space
spectaculars like the
Apollo moon landings, they offer the best hope for studying the
planets and,
perhaps one day, the stars.
The success of Pathfinder, and its little rover vehicle
Sojourner, proves
that the planets can be explored remotely. NASA must now devote
more effort
to improving the performance and extending the reach of its
unmanned probes.
There is enormous potential for developing smaller, faster and
cheaper
payloads. Sensor technology is progressing by leaps and bounds,
with
emphasis on micro-miniaturisation. Robotics is moving beyond the
entertainment phase into the seriously useful. Electronics and
computer
technology is fast approaching the stage where a small space
probe can
accommodate a supercomputer.
The vast information processing power of supercomputers will open
up a much
wider range of possible extraterrestrial activities. No longer
will a probe
simply be plonked on the surface of a planet, or put into orbit,
and
laboriously instructed on a move-by-move basis from Earth.
Decisions that
must now be referred back to engineers and project scientists at
mission
control will in future be taken on the spot, using artificial
intelligence.
The burgeoning use of neural nets in place of traditional digital
programming techniques promises to revolutionise the development
of
intelligent machines. Neural nets can be trained like humans,
learning from
experience and avoiding future mistakes. They will prove ideal
for smart
rover vehicles, which could be trained on Earth and released on
Mars or the
moon, left largely to their own devices.
The trend towards smaller and smarter space probes looks set to
parallel the
history of computers and similar electronic devices. Thirty years
ago a
modest number-cruncher filled a large room, requiring a huge
power supply
and elaborate cooling procedures to sustain it. Today the same
computing
power is achieved in a pocket-sized pack run by a battery.
In the electronics industry, shrinking size also brought
shrinking costs and
mass-production. The space probes of the future could be turned
out in their
thousands for the price of a car apiece, and be no larger than a
football.
Smaller, lighter probes bring a benefit in terms of speed and
launch
economy. State of the art rockets could launch them to the
planets by the
score. Even if half failed to achieve their objectives, plenty
more would be
available. In space exploration, small is beautiful.
Two scientific developments offer hope of spectacular advances in
miniaturisation. The first is nanotechnology. A few weeks ago,
American
scientists released pictures of a guitar one twentieth the width
of a human
hair. Physicists can now trap and manipulate individual atoms.
IBM engineers
have succeeded in imprinting their company's initials, atom by
atom, on a
crystalline surface less than a millionth of a centimetre across.
At present, creating micro-machines is still largely a gimmick,
but advances
are so rapid that we will soon have sensors and processors too
small to be
seen by the naked eye monitoring our environment and even
inhabiting our
bodies.
With such technology, there is no reason why certain types of
space probe
couldn't become very small indeed. Designers at the Los Alamos
National
Laboratory in the United States are currently working on an
artificial
satellite that is as small as a coin. Modest launch vehicles
could flood the
solar system with devices of this size. Rather than settling for
one or two
large and expensive spacecraft stranded on a couple of planets,
we could
instead have a vast network of micro-probes milling around the
solar system
like fireflies, exchanging information via a celestial internet.
The other field that is forging ahead is genetic engineering.
Already
researchers are creating artificial organisms adapted for harsh
conditions
on Earth. They could soon be making new organisms for use on
other planets
or even in outer space. Bacteria are known that can survive
unprotected in
the hazardous conditions of space.
It may be possible to engineer larger organisms with space
capability too.
Imagine a genetically-engineered spider that could crawl over an
asteroid or
planet and collect selected particles of rock instead of flies.
Or a
butterfly complete with microsensors fluttering in the thin
martian
atmosphere.
Author George Dyson takes a futuristic look at biotechnology in a
provocative new book entitled Darwin Among the Machines. He sees
genetically-engineered insects as the next stage of DNA
technology. "Insects
might be reinvented from the top down by miniaturization of
machines, but we
are more likely to reinvent them from the bottom up, by
recombinant
entomology," he writes.
George Dyson's father, Freeman Dyson, is a physicist at the
Institute for
Advanced Study in Princeton, and a longstanding advocate of the
small-and-smart approach to space probes. At a lecture in
Adelaide in 1986
he announced his concept of the Astrochicken - a one-kilogram
spacecraft
about the same size as a chicken 'and equally smart'. Both father
and son
forsee, within the next two decades, the merging of
nanotechnology and
genetic engineering, to create hybrid entities, part organic,
part machine.
This idea is not as fanciful as it may seem. Last June, Federal
Science
Minister Peter McGauran unveiled a new biosensor designed by
Bruce Cornell
of the Cooperative Research Centre for Molecular Engineering and
Technology
in Sydney. The device is just over a millionth of a metre in size
and is so
sensitive it is reportedly capable of detecting a single sugar
lump
dissolved in Sydney Harbour.
Significantly, the new sensor is fabricated by grafting gold
electrodes onto
an organic cell membrane. But this is just the beginning.
Microbiologists
have discovered that living cells contain pumps, levers, shears,
valves,
pipes and chains, all too small to be seen without a microscope,
and all
capable of being adapted for artificial use.
Twenty years ago I suggested in a flight of fancy that an
advanced alien
civilisation might be able to manufacture hybrid
machine-organisms that
could grow from seeds sent to a suitable host planet. They would
develop
"eyes", "ears" and other sensors, and even
sprout a radio antenna to send
back the data, using local resources and energy supplies. Little
did I
suspect that human science would soon fix its sights on such
technology.
With lilliputian machines and powerful data processing, the way
lies open to
alternative launch technologies. A pea-sized probe could
withstand enormous
acceleration without being pulverised. H.G. Wells, writing before
the age of
rockets, sent his men to the moon using a giant gun. In practice,
the
impulse would prove lethal to astronauts, but micro-probes could
readily be
delivered into space that way.
Proposals have been made for electromagnetic guns and accelerator
machines
to propel objects from the Earth at relatively low cost.
Amazingly, this
idea predates the space age. In 1947, Clarke, then still a
student in
London, wrote the first of many prophetic books. Called Prelude
to Space, it
outlines a method for catapaulting an atomic rocket into orbit by
accelerating it along a rail track to 800 km per hour. Clarke
suggested
constructing the electromagnetic accelerator in the Australian
desert.
Under the impetus of the Star Wars research program, several
variants of
Clarke's imaginative idea have been mooted in recent years. All
of them seek
to avoid the basic shortcoming of rocket technology - the need to
lift most
of the fuel with the payload. But to achieve really high speeds,
the launch
system has to be located in space already, or on the moon, to
avoid air
friction. An orbiting electromagnetic launcher could be a cheap
way of
sending small probes to the planets quickly and in large numbers.
Even with these exciting developments, reaching the stars won't
be easy.
Nevertheless, the possibility that mankind will one day be able
to send tiny
probes zooming across the galaxy at half the speed of light is
not too
far-fetched. Indeed, NASA has just embarked on a feasibility
study for an
interstellar probe.
Given that the thrust of technology is towards the smaller and
lighter, is
there any future at all for manned deep-space missions, with
their demand
for bulky life support-systems and fail-safe back-up? Possibly.
Going to
Mars remains a feasible goal, though the $540 billion US dollar
price tag
that attached to President George Bush's Mars' initiative is
clearly
prohibitive.
If mankind is ever to set foot on the red planet, NASA will need
to adopt
the sort of ingenious strategy advocated by Zubrin, who wants to
send ahead
an unmanned vehicle with an empty tank, and manufacture the fuel
for the
return journey on the martian surface. Mars has both water and
carbon
dioxide, which can be slowly turned in methane, a good rocket
propellant. By
avoiding the need to send the fuel from Earth, launch costs
plummet.
Zubrin has estimated that efficiency savings of this sort could
bring the
total cost of the mission down to around $20 billion - about the
same as
building and operating the planned international space station
for a few
years. It is also, incidentally, less than ten times the sum lost
in one
year by the State Bank of South Australia.
A manned expedition to Mars would undoubtedly bring some
scientific
benefits, but its main purpose would be cultural. As a human
adventure it
would be without equal - an uplifting, unifying project suitable
for the new
millenium. But a stairway to the stars it is not.
Copyright 1999-2002, Paul Davies
===========
(2) CAN MICROBES RAIN DOWN FROM SPACE? MORE SUPPORT FOR
CONTROVERSIAL THEORY
>From Space.com, 17 December 2002
http://www.space.com/scienceastronomy/space_bugs_021217.html
By Robert Roy Britt
A controversial finding last year of microbes high in Earth's
atmosphere and
thought to have come from space gained another scientist's
support this
week.
The organisms, collected by a balloon mission to the stratosphere
in January
2001, were first studied by Chandra Wickramasinghe of Cardiff
University,
co-proponent with the late Sir Fred Hoyle of the modern theory of
panspermia. The theory states that the Earth was seeded in the
past, and is
still being seeded, with microorganisms from comets.
The experiment gathered microbes as high as 25 miles (41
kilometers). The
quantity suggested a ton of them rain down on Earth daily. The
critters
looked a lot like terrestrial microbes, however, and other
scientists have
suggested they probably were from Earth and that the experiment
was
contaminated.
Now Milton Wainwright of Sheffield University's Department of
Molecular
Biology and Biotechnology claims to have isolated a fungus and
two bacteria
from one of the samples. The results are published in this
month's issue of
the microbiology journal FEMS Letters. Once again, the organisms
are very
similar to known terrestrial varieties. There are, however,
"notable
differences in their detailed properties, possibly pointing to a
different
origin," according to a press release.
Other scientists point out that previously unknown strains of
bacteria are
routinely discovered on Earth.
"Contamination is always a possibility in such studies, but
the 'internal
logic' of the findings points strongly to the organisms being
isolated in
space," Wainwright said. "Of course the results would
have been more readily
accepted and lauded by critics had we isolated novel organisms,
or ones with
NASA written on them!"
Indeed.
Panspermia adherents predict the continuing input onto the Earth
of fresh
organisms that would have untold effects on evolution and might
even seed
illness. The theory supposes a certain hardiness inherent in
space-travelling bacteria.
An announcement yesterday of the revival of 2,800-year-old
bacteria found
buried in Antarctic ice certainly attests to the extreme
capabilities of
small things. Yet few mainstream scientists have signed on to
panspermia.
Most leading researchers do acknowledge that life probably could
travel
between planets, however, embedded inside rocks kicked up by
asteroid or
comet collisions.
No proof exists that life has traveled between planets, though.
And no one
has formally ruled out panspermia in its purest form, either.
Copyright 2002, Space.com
============
(3) HYDROCARBON BUBBLES DISCOVERED IN METEORITE
>From New Scientist, 17 December 2002
http://www.newscientist.com/news/news.jsp?id=ns99993189
Hollow hydrocarbon bubbles a few microns in diameter have been
discovered in
a meteorite that crashed into a frozen lake in Canada in 2000.
The simple organic structures could have provided a sheltered
environment
for the development of the first primitive organisms, suggests
Michael
Zolensky, at NASA's Johnson Space Center.
He used an electron microscope to discover the globules, which
are a few
microns in diameter. "These are ready-made homes," he
told New Scientist.
"It shows that structures that could protect early life were
present on
asteroids billions of years ago."
It is the first time that such bubbles have been found on a
meteorite, but
laboratory experiments designed to simulate conditions in space
have
produced similar structures.
"Some ideas for the evolution of life require a kind of
membrane to hold
together all the chemicals that you want a cell to use,"
says Iain Gilmour,
of the UK's Open University. "If you have some sort of
globular structure,
you've got the start of a potential cell structure."
Other researchers have suggested that tiny cavities in minerals
could have
provided the containers from which the first cellular life
emerged.
Quick freeze
The meteorite, a carbonaceous chondrite, was recovered from the
frozen
waters of Tagish Lake in the Yukon Territory in January 2000,
just a week
after it landed. The extreme cold of the lake and the speed at
which it was
recovered prevented the contamination that spoils many meteorites
found on
Earth.
The circumstances under which the cavities could aid the
development of life
remain unclear. But Zolensky notes meteorites of this general
type have been
crashing into Earth throughout its history.
They would have provided the early planet with these hydrocarbon
globules at
the same time as water, carbon and organic molecules were being
bought to
Earth on comets and meteorites, he says, and at the same time the
first
terrestrial life was developing.
Much previous research into potential extraterrestrial triggers
for life on
Earth has focused on meteorites that landed in Murchison,
Southern Australia
in 1969. These contained amino acids, the building blocks of
proteins and
life, and showed for the first time that the molecules could
exist elsewhere
in the Solar System.
Gilmour says: "It means you've got the stuff you need to
make proteins in
one extra-terrestrial sample and the stuff needed to hold them
together in
another." Zolensky's research is published in the
International Journal of
Astrobiology.
Will Knight
Copyright 2002, New Scientist
===========
(4) SCARS LEFT BY A SPACE ROCK CRATER: A METEORITE IMPACT IN
ARIZONA ABOUT
50,000 YEARS AGO LEFT A MARK THAT CHANGED THE LANDSCAPE AND
SCIENCE
>From Baltimore Sun, 16 December 2002
METEOR CRATER, Ariz. -- About 50,000 years ago, a fireball
streaked across
the sky at 11 miles per second and crashed into the desert here,
triggering
a blast 1,000 times more powerful than the atomic bomb that
devastated
Hiroshima.
The meteorite was 150 feet wide and weighed 300,000 tons. In less
than 10
seconds, it sent 175 million tons of material flying miles in all
directions. The blast killed all the animal life -- mastodons,
mammoths,
giant ground sloths and bison -- within several miles. It created
a crater 2
1/2 miles in circumference, 750 feet deep and 4,100 feet wide.
Today, scientists consider this gigantic hole, known as the
Barringer
Meteorite Crater, to be the world's youngest (sic) and
best-preserved impact
crater.
About 300,000 visitors view the crater annually. It's located on
privately
owned land in northern Arizona's high desert, about 35 miles east
of
Flagstaff and 20 miles west of Winslow.
A dark gray meteorite about 3 feet long and weighing a whopping
1,400 pounds
is on display in the crater's museum. This chunk of dense metal
-- 92
percent iron, 7 percent nickel and 1 percent trace metal -- was
found in
Diablo Canyon, about 2 miles from the crater. It is believed to
have broken
off from the larger meteorite before it hit the ground and
exploded.
Clifford Mark, a tour guide, urges visitors to rub the meteorite
for good
luck.
"Lightning never strikes twice in the same place, and if you
touch this
metallic meteorite, your chances of getting hit by one are cut in
half,"
Mark explains in jest.
Actually, the odds of a person getting hit by a chunk of
celestial matter
are about 1 in 10 billion. But it has happened. In 1954, Hewlett
Hodges was
lying on the sofa of her home in Sylacauga, Ala., when a
meteorite crashed
through the roof. The hot rock bounced off a table and grazed her
leg. She
was lucky. In 1650, an Italian monk was killed by a piece of a
meteorite,
according to legend.
Standing on the crater's 150-foot-tall rim, Mark points to a
piece of
wreckage that has been on the crater's floor since the late
1960s. He tells
a story that suggests that the world has more to fear from people
flying
small planes than rocks falling from outer space.
"Two guys in a single-engine Cessna decided to fly into the
crater to get a
closer look," he explains. "But when they got in, they
couldn't get out.
There's a layer of wind spins over the crater like an invisible
force field.
Two and a half hours later, they ran out of gas and tried to
land, but the
plane cartwheeled and crashed. They were lucky, they lived."
Today, earth and rock have settled in the crater and decreased
its depth to
about 570 feet -- deep enough to swallow the Washington Monument
in the
nation's capital. Mark says that if the crater was turned into a
makeshift
stadium, 20 football games could be played on its floor
simultaneously
before an audience of 2 million spectators seated on its sloping
sides.
"We're talking about the world's biggest Super Bowl
party," he says.
The crater is named after Daniel Moreau Barringer, a Philadelphia
lawyer and
mining engineer. Barringer, a member of Princeton University's
Class of 1879
and a graduate of the University of Pennsylvania Law School,
abandoned his
law practice to pursue a career in mining. After attending the
Colorado
School of Mines, he headed to Arizona and struck it rich with a
silver mine.
In 1902, Barringer became fascinated with the crater. Many
scientists
believed it had been formed by a volcanic steam explosion beneath
the earth.
But Barringer was convinced that an extraterrestrial body formed
the hole
and beneath it lay $500 million worth of high-grade nickel-iron.
After discovering that the land belonged to the federal
government,
Barringer obtained a patent that gave him the mining rights. From
1903 until
shortly before his death in 1929, Barringer squandered a small
fortune
mining the site. He gave up after a respected astronomer
concluded that the
meteorite had vaporized on impact. A short while later, Barringer
suffered a
fatal heart attack.
While Barringer's quest for personal wealth was a dismal failure,
his
contribution to science was significant. In 1905, he published a
paper
stating that the crater had been formed by an object from outer
space,
possibly a small asteroid. He based his idea on meteorite
fragments he found
in finely powdered sand. Eventually, geologists came to accept
his idea that
rocks can fall from the sky and create gigantic craters.
In the late 1950s, Gene Shoemaker, a planetary scientist
specializing in
meteor impacts, made a major discovery on the floor of the
Barringer Crater.
He found a mineral called coesite, which is created only by the
high
pressure and heat of impact. Scientists have used his findings to
identify
other craters around the world.
Shoemaker, along with his wife, Carolyn, and another researcher,
David Levy,
identified the comet Shoemaker-Levy 9 that crashed into Jupiter
in 1994.
Shoemaker died in a car crash five years ago while searching for
craters in
Australia.
An estimated 25,000 meteorites hit the Earth annually, and most
cause little
or no damage. The shooting stars that flash across the nighttime
sky are
pin-size dust specks burning in the atmosphere.
Craters are formed by very large objects that are not slowed
downed or
cushioned as they hurtle through the Earth's atmosphere.
Worldwide, there
are at least 170 impact craters, and the Barringer Meteorite
Crater is far
from the largest.
In 1991, a huge crater called Chicxulub was discovered on the
Yucatan
Peninsula. This hole is about 110 miles wide, and it is believed
to be about
65 million years old, hitting about the time when the dinosaurs
died off. It
is believed that the explosion kicked up a dust cloud that
blocked out
sunlight, causing the Earth's temperature to drop.
The theory linking the extinction of the dinosaurs to an
explosion caused by
a body from outer space is about 20 years old. It is the
brainchild of Luis
W. Alvarez and his son, Walter Alvarez. But their theory is being
challenged
by new scientific research suggesting that the Earth might have
been hit by
a swarm of smaller objects instead of a single large one.
Scientists have discovered 1,000 to 1,500 near-Earth asteroids
that are less
than a mile in diameter, as well as many smaller ones. It is
likely that one
day, one will be on a collision course with Earth, but that
potential
catastrophe is likely to happen tens, hundreds or thousands of
years from
now, they say.
But during the summer, an asteroid the size of a football field
missed the
Earth by a mere 75,000 miles and was not detected until three
days after it
passed. In March, a 165-foot- wide chunk of rock passed within
288,000 miles
of Earth.
A collision with either object would have caused a blast equal to
millions
of tons of TNT.
Copyright © 2002 The Baltimore Sun.
============================
* LETTERS TO THE MODERATOR *
============================
(5) ON THE EXISTENCE OF A PLANET X
>From Mario D Melita <m.d.melita@qmul.ac.uk>
Dear Benny:
The problem of the existence of a trans-Plutonian planet has been
taken by
the media lately. I would like to discuss my views about it.
Our work was published in Icarus, 160, 1, 32-43.
http://www-star.qmul.ac.uk/~melita/BMpaper2.ps.
Our goal has been to determine if the apparent 'edge' of the
Kuiper Belt is
actually a gap cleared by an inner-planet-sized object.
A summary of our results follows.
We study the effects of a massive body on a disk of massless
particles,
which are meant to represent the Kuiper Belt. Our results
indicate that:
1. A gap 'consistent' with the observations can be created over
the age of
the Solar System. The mass of the object should be of the order
of that of
Mars. Its semimajor axis about 60 AU and eccentricity of \sim
0.1.
2.The inclination distribution is better reassembled when the
object is in a
moderately inclined orbit (10-20
deg).
3. The Plutino population must be assumed to be more numerous
than at
present. The perturbation on the rather 'fragile' orbits in the
2:3
mean-motion-resonance with Neptune can be considerable, and some
70% should
be assumed to be lost.
In a sense this is a preliminary result. The 'consistency' with
the
observations is not such. We only compare the end-state of our
simulation
with the observed distribution. A re-assessment of this
hypothesis is in
progress, where we estimate selection effects.
In an a-e plot, the end-state of our simulations look like
bell-shaped cloud
about the position of the planetoid. Hence, there is a leftover
of objects
with perihelion beyond 40AU, at large semimajor axes and moderate
eccentricities which are observable but are not seen. We also
describe a
scenario, in which the object is transported from the
Uranus-Neptune region,
which would widen the gap. In any way, the disk should reassume
after a
certain distance if we are observing a gap and not an edge. I
also believe
that from the observed features of the Kuiper Belt some other
constraints
can be drawn about the existence of 'Planet X'.
Regarding detectability. I believe that there is a chance that it
has
escaped the optical surveys if it is in a fairly inclined orbit
and far from
the node. IRAF may have missed it if its albedo is not too high
or it is in
the galactic plane.
Since the discovery of 1992 QB1 the Kuiper Belt has been full of
surprises.
We do not know yet if this is another of
them.
Finally, it should be noticed that we are discussing about an
object which
is quite smaller and more distant than those required by the
'Planet X
theories' about the residual of the ephemerides of Uranus, which,
anyhow,
are not believed to be necessary any longer.
Regards, Mario
Mario D. Melita
Astronomy Unit
Queen Mary
University of London
Mile End Road
London E1 4NS
TEL 0044 (0)20 7882 3181
Fax 0044 (0)20 8983 3522
M.D.Melita@qmul.ac.uk
==============
(6) MIDDLE-EARTH IN THE SKY?
>From Govert Schilling <mail@govertschilling.nl>
The fantasy books of J.R.R. Tolkien are more popular than ever,
thanks to
the impressive movie trilogy by Peter Jackson. 'The Lord of the
Rings' has
also recently been voted the greatest book of the twentieth
century by a
British poll conducted by Channel 4 and the Waterstone's
bookstore chain.
Indeed, some scholars argue that the Tolkien books on the history
of
Middle-Earth (including 'The Silmarillion' and 'The Hobbit') are
comparable
to classical myths in every sense. They may well become an
inseparable part
of human culture.
In my opinion, it would be most fitting that characters from the
Tolkien
books are immortalized in the sky. With names from traditional
myths and
legends almost running out, astronomers may want to turn to the
impressively
large cast of characters of Middle-Earth in search for names for
new solar
system bodies or features. A couple of months ago, I proposed
this idea to
Brian Marsden of the Harvard-Smithsonian Center for Astrophysics,
and he
responded: "Actually, your proposal has a lot of merit,
[...] perhaps for
some of the TNOs. We need in particular a set of names for the
scattered-disk objects, for these were not covered in the
original IAU
scheme of "creation gods" for the cubewanos and
"underworld gods" for the
plutinos." According to Marsden, he has mentioned the
suggestion in the
appropriate IAU Committee on Small Body Nomenclature, but
apparently, it has
not been accepted so far.
If any other readers of this list agree that it would be a great
idea to
name the scattered-disk objects after Tolkien characters, I would
urge them
to send an email expressing support to this proposal to the
committee
chairman (Pam Kilmartin, p.kilmartin@phys.canterbury.ac.nz)
or to the
secretary (Brian Marsden, bmarsden@cfa.harvard.edu).
Govert Schilling, Utrecht, the Netherlands
freelance astronomy writer
mail@govertschilling.nl
http://www.govertschilling.nl
============
(7) CATASTROPHIC DISRUPTION IN THE SOLAR SYSTEM
>From Patrick Michel <michel@obs-nice.fr>
MEETING: Sixth Workshop on Catastophic Disruption in the Solar
System.
PLACE: Cannes, France
DATES: June 9-11, 2003.
DEDICATION: Dr. Paolo Farinella
SCIENTIFIC ORGANIZING COMMITTEE: Dan Durda (Chair), Erik
Asphaug,
Kevin Housen, Patrick Michel, and Akiko Nakamura.
Patrick Michel will take care of local arrangements and gourmet
feasting and
will be the conference administrator.
The workshop will take place in the heart of the legendar French
Riviera in
Cannes with its unequalled bay, traditions, and surrounded by
small typical
villages. The Croisette Beach Hotel in which the meeting will
take place is
located only a short step from the beaches of La Croisette, and a
few
minutes by walk from the old town with its typical architecture,
restaurants
and local people.
A web site devoted to the workshop may be found at:
http://www.boulder.swri.edu/~durda/cd6/meeting.html
In addition to emailed announcements, additional information
(links, PDF
forms, etc.) will be placed on this site and we encourage
participants to
check this site for updates.
The Hotel itself has 50 rooms blocked for us, all with the modern
confort of
a four-star Hotel (maximum number of stars in France):
soundproofed with
air-conditionning, colour cable TV and
filter power outlet for computer equipment (for further
information, visit
the Croisette Beach home page: http://www.croisettebeach.com/).
To make their room reservation, participants are required to fill
the form
at the end of this announcement and fax it DIRECTLY TO the Hotel
(note: the
Hotel is closed until December 27th 2002, so the form should be
faxed
preferentially after this date BUT BEFORE March 17th 2003); the
dealines and
cancellation penalties are well indicated and participants can
also contact
the Hotel by phone if any other details or requirements are still
needed. An
application form including other needed information (title of
potential talk
etc ..) is also situated at the end of this announcement and must
be filled
and sent by email to michel@obs-nice.fr
The format of the meeting, in keeping with the workshop spirit,
will allow
ample time for discussion. The Scientific Program includes
invited reviews
on the main topics and each session will be orgnized starting by
an invited
review and followed by talks on the same topics with as much time
as
necessary for discussions. The main topics and Invited Reviewers
(IR) are:
----
I Confrontation laboratory experiments - observations
- models
I-A Impacts in Strength Regime
I-A-1 Impact Experiments (laboratory and in-the-field) IR:
A. NAKAMURA
I-A-2 Models of Impact Experiments (numerical and analytical
explanations/examinations)
IR: E. ASPHAUG
I-A-3 Scaling IRs: K. HOUSEN/K. HOLSAPPLE
I-B Beyond the Strength Regime
I-B-1 Constraints from observations
I-B-1-a Asteroid Families IR: A. CELLINO
I-B-1-b Asteroid Observations (rotation, satellites, ...)
IR: A.W. HARRIS
I-B-2 Numerical models
I-B-2-a Numerical Models (hydrocodes) and simulation of small
body
collisions IR:
P. MICHEL
I-B-2-b BIG Collisions (Earth-Moon, Pluto/Charon, etc.) IR:
R. CANUP
II Material Properties, Physical Structure
II-1 Porosity/Highly Compressible Materials IRs: K.
HOLSAPPLE/K. HOUSEN
II-2 Meteoritical Evidence/Constraints for
Impacts/Disruption IR:
CONSOLMAGNO
II-3 Geological Properties of Asteroids from Spacecraft
Observations
IR: to be determined
II-4 Rubble Piles and Monoliths IR: D.C. RICHARDSON
III Collisonal Evolution Models
III-1 Collisional Evolution Models/Size Distributions IR: F.
MARZARI
III-2 Catastrophic disruption threshold and internal structure
IR: W. BENZ
III-3 Disruption/Splitting of Comets (tentative IR: P. WEISSMAN)
----
We anticipate the registration fees to be around 150 Euros at
most, but the
final amount depends on how much additional support we can
obtain. The
amount and payment will be asked later. The Workshop will start
by a welcome
buffet on the beach on Sunday June 8th in the evening and
it will include a evening banquet on Tuesday June 10th in Mougins
(one of
the small villages surrounding Cannes). Every Lunch during the
workshop will
also consist in buffets (hot and cold) on the beach, including
vegetarian
plates. These social events are free for the participants.
Finally, the Proceedings of this workshop will be published in
the Journal
Icarus (to be confirmed).
We will let you know other details in the next annoucements.
Given the
limited number of rooms, we encourage people willing to
participate to
reserve their Hotel room as fast as possible by sending the form
below by
fax to the Hotel, and we thank you in advance for sending back
also as soon
as possible the application form placed after the room
reservation form by
email to michel@obs-nice.fr.
Patrick Michel
Dan Durda Donald R. Davis
michel@obs-nice.fr durda@boulder.swri.edu
drd@psi.edu
==============
(8) AND FINALLY: DARWIN IN THE CLASSROOM. OHIO ENCOURAGES
CRITICAL SCIENCE
EDUCATION
>From National Review, 17 December 2002
http://www.nationalreview.com/comment/comment-west121702.asp
By John G. West Jr.
After months of debate, the Ohio State Board of Education
unanimously
adopted science standards on Dec. 10 that require Ohio students
to know "how
scientists continue to investigate and critically analyze aspects
of
evolutionary theory."
Ohio thus becomes the first state to mandate that students learn
not only
scientific evidence that supports Darwin's theory but also
scientific
evidence critical of it. While the new science standards do not
compel
Ohio's school districts to offer a specific curriculum, Ohio
students will
need to know about scientific criticisms of Darwin's theory in
order to pass
graduation tests required for a high-school diploma.
Ohio is not the only place where public officials are broadening
the
curriculum to include scientific criticisms of evolution. In
September the
Cobb County School District in Georgia, one of the largest
suburban school
districts in the nation, adopted a policy encouraging teachers to
discuss
"disputed views" about evolution as part of a
"balanced education." And last
year, Congress in the conference report to the landmark No Child
Left Behind
Act urged schools to inform students of "the full range of
scientific views"
when covering controversial scientific topics "such as
biological
evolution."
After years of being marginalized, critics of Darwin's theory
seem to be
gaining ground. What is going on? And why now?
Two developments have been paramount.
First, there has been growing public recognition of the shoddy
way evolution
is actually taught in many schools. Thanks to the book Icons of
Evolution by
biologist Jonathan Wells, more people know about how biology
textbooks
perpetuate discredited "icons" of evolution that many
biologists no longer
accept as good science. Embryo drawings purporting to prove
Darwin's theory
of common ancestry continue to appear in many textbooks despite
the
embarrassing fact that they have been exposed as fakes originally
concocted
by 19th-century German Darwinist Ernst Haeckel. Textbooks
likewise continue
to showcase microevolution in peppered moths as evidence for
Darwin's
mechanism of natural selection even though the underlying
research is now
questioned by many biologists.
When not offering students bogus science, the textbooks ignore
real and
often heated scientific disagreements over evolutionary theory.
Few students
ever learn, for example, about vigorous debates generated by the
Cambrian
Explosion, a huge burst in the complexity of living things more
than 500
million years ago that seems to outstrip the known capacity of
natural
selection to produce biological change.
Teachers who do inform students about some of Darwinism's
unresolved
problems often face persecution by what can only be termed the
Darwinian
thought police. In Washington state, a well-respected biology
teacher who
wanted to tell students about scientific debates over things like
Haeckel's
embryos and the peppered moth was ultimately driven from his
school district
by local Darwinists.
Science is supposed to prize open minds and critical thinking.
Yet the
theory of evolution is typically presented today completely
uncritically, as
a dogma to be accepted rather than as a theory to be explored and
questioned. Is it any wonder that policymakers and the public are
growing
skeptical of such a one-sided approach?
A second development fueling recent gains by Darwin's critics has
been the
demise of an old stereotype.
For years, Darwinists successfully shut down any public
discussion of
Darwinian evolution by stigmatizing every critic of Darwin as a
Biblical
literalist intent on injecting Genesis into biology class. While
Darwinists
still try that tactic, their charge is becoming increasingly
implausible,
even ludicrous. Far from being uneducated Bible-thumpers, the new
critics of
evolution hold doctorates in biology, biochemistry, mathematics
and related
disciplines from secular universities, and many of them teach or
do research
at American universities. They are scientists like Lehigh
University
biochemist Michael Behe, University of Idaho microbiologist Scott
Minnich,
and Baylor University philosopher and mathematician William
Dembski.
The ranks of these academic critics of Darwin are growing. During
the past
year, more than 150 scientists - including faculty and
researchers at such
institutions as Yale, Princeton, MIT, and the Smithsonian -
adopted a
statement expressing skepticism of neo-Darwinism's central claim
that
"random mutation and natural selection account for the
complexity of life."
Deprived of the stock response that all critics of Darwin must be
stupid
fundamentalists, some of Darwin's public defenders have taken a
page from
the playbook of power politics: If you can't dismiss your
opponents,
demonize them.
In Ohio critics of Darwinism were compared to the Taliban, and
Ohioans were
warned that the effort to allow students to learn about
scientific
criticisms of Darwin was part of a vast conspiracy to impose
nothing less
than a theocracy. Happily for good science education (and free
inquiry), the
Ohio Board of Education saw through such overheated rhetoric. So
did 52 Ohio
scientists (many on the faculties of Ohio universities) who
publicly urged
the Ohio Board to require students to learn about scientific
criticisms of
Darwin's theory.
The renewed debate over how to teach evolution is not likely to
stop with
Ohio.
Under the No Child Left Behind Act, every state must enact
statewide science
assessments within five years. As other states prepare to fulfill
this new
federal mandate, one of the looming questions will be what
students should
learn about evolution. Will they learn only the scientific
evidence that
favors the theory, or will they be exposed to its scientific
criticisms as
well?
Ohio has set a standard other states would do well to follow.
- John West is a senior fellow of the Seattle-based Discovery
Institute and
chair of the department of political science at Seattle Pacific
University.
Copyright 2002, National Review
--------------------------------------------------------------------
CCNet is a scholarly electronic network. To
subscribe/unsubscribe, please
contact the moderator Benny J Peiser < b.j.peiser@livjm.ac.uk
>. Information
circulated on this network is for scholarly and educational use
only. The
attached information may not be copied or reproduced for any
other purposes
without prior permission of the copyright holders. The fully
indexed archive
of the CCNet, from February 1997 on, can be found at
http://abob.libs.uga.edu/bobk/cccmenu.html.
DISCLAIMER: The opinions,
beliefs and viewpoints expressed in the articles and texts and in
other
CCNet contributions do not necessarily reflect the opinions,
beliefs and
viewpoints of the moderator of this network.
----------------------------------------------------------------------------