PLEASE NOTE:
*
CCNet 45/2003 - 15 May 2003
"Scientists studying rocks near an ancient asteroid impact
structure in South Australian have uncovered evidence that
could change current theories explaining how life on Earth
rapidly diversified about 580 million years ago. In the May
edition of the international journal Geology, Dr Grey and her
team put forward an alternative radical idea that 580
million years ago an asteroid impact played a pivotal role in
this evolutionary jump. Up until then, for the first three
billion years of Earth's 4.5 billion year history, bacteria and
simple algae had dominated life on Earth. "Then almost
overnight geologically speaking, the ancestors of modern day
animals and plants appeared in the fossil record about half
a billion years ago," Dr Grey said. "The big question
is what caused the rapid proliferation of life at that
time?"
--The Australian Centre for
Astrobiology, May 2003
"Shame on us if we can't get into space and terraform some
piece of rock with our knowledge and survive indefinitely by
moving when it is necessary."
--Lynda, Cosmic Log, 14 May 2003
"[Michio] Kaku launches into a discussion of wormholes,
superstrings, and other exotica of modern cosmology. After
billions of years, even galactic civilizations are doomed, as the
universe freezes in a Big Chill or collapses in a Big
Crunch. But on the book's last page a new category is introduced:
the Type IV civilization, masters of space and time.
Such beings might be able to build tunnels to parallel universes.
Here, then, is Kaku's ultimate statement of
technological optimism: Intelligent life might survive the end of
our universe."
--Kenneth Silber,
Reason Magazine, May 1998
(1) "ASTEROID IMPACT PLAYED PIVOTAL ROLE IN RAPID
PROLIFERATION OF LIFE"
Ron Baalke <info@jpl.nasa.gov>
(2) METEORITES RAINED ON EARTH AFTER MASSIVE ASTEROID BREAKUP
Rice University, 8 May 2003
(3) CAMERAS CAPTURE A 5-SECOND FIREBALL AND ITS METEORITE'S
SECRET
Andrew Yee <ayee@nova.astro.utoronto.ca>
(4) METEOR'S FAMILY POSES PUZZLE
BBC News Online, 8 May 2003
(5) THE NEUSCHWANSTEIN METEORITE
Nature 423, 151 - 153 (2003);
doi:10.1038/nature01592
(6) TWO-WAY ASTEROID TRIP TAKES OFF
Astrobiology Magazine, 12 May 2003
(7) SCIENTISTS FORESEE THE END OF THE EARTH
Space.com, 12 May 2003
(8) WHAT DO YOU THINK HUMANITY'S FATE ON EARTH WILL BE ?
MSNBC.com, 12 May 2003
(9) REVISITING THE END OF THE WORLD
Alan Boyle's Cosmic Log, 14 May 2003
(10) IMPACT PAPERS IN ASTROBIOLOGY JOURNAL
Michael Paine <mpaine@tpg.com.au>
(11) HOT-HOTSPOTS
Hermann Burchard <burchar@math.okstate.edu>
(12) MULTIPLE IMPACT EVIDENCE AT CHICXULUB
Hermann Burchard <burchar@math.okstate.edu>
(13) AND FINALLY: "MASTERS OF THE UNIVERSE". AN
ANTIDOTE TO CARTER'S DOOMSDAY ARGUMENT & SECULAR
TECHNO-PESSIMISM
Reason Magazine, May 1998
=======
(1) "ASTEROID IMPACT PLAYED PIVOTAL ROLE IN RAPID
PROLIFERATION OF LIFE"
Ron Baalke <info@jpl.nasa.gov>
http://aca.mq.edu.au/acraman.htm
The Australian Centre for Astrobiology
May 2003
Scientists studying rocks near an ancient asteroid impact
structure in South Australian have uncovered evidence that
could change current theories explaining how life on Earth
rapidly
diversified about 580 million years ago.
Dr Kath Grey of the Western Australian Department of Industry and
Resources' Geological survey and an ACA associate
researcher, Prof Malcolm Walter, Director of the ACA and Dr Clive
Calver of the Tasmanian Department of Mineral
Resources challenge the idea that 'Snowball Earth' - an intense
period of glaciation about 600 million years ago,
triggered the evolution of simple life forms into more complex
and familiar species.
In the May edition of the international journal Geology, Dr Grey
and her team put forward an alternative radical idea
that 580 million years ago an asteroid impact played a pivotal
role in this evolutionary jump. The impact, known as the
Acraman event, smashed a hole in South Australia about four times
the size of Sydney.
Up until then, for the first three billion years of Earth's 4.5
billion year history, bacteria and simple algae had
dominated life on Earth. "Then almost overnight geologically
speaking, the ancestors of modern day animals and plants
appeared in the fossil record about half a billion years
ago," Dr Grey said. "The big question is what caused
the rapid
proliferation of life at that time?"
Research by other scientists suggests the evolutionary burst of
life between 600 and 540 million years ago was the
result of an intense period of global glaciation. However, if the
findings of Dr Grey's research prove correct, the
cause could lie beyond our planet.
Dr Grey, who has studied fossil plankton (single-celled green
algae) from drill holes across Australia, has found that,
as predicted by the Snowball Earth theory, bacterial mats and a
few simple spherical species of plankton were the only
organisms that managed to survive the intense ice age.
"As the sea level rose at the end of the ice age, these
spherical forms increased in number," Dr Grey said.
"But there
is no sign of a new species emerging at the end of the intense
ice age to support ideas of the rapid diversification of
life at this time."
Dr Grey believes it wasn't until about 20 million years later
more than 50 new and highly complex species suddenly
replaced the small number of simple species in the fossil record.
"What is really interesting is that the more complex spiny
fossils appear just above a layer of rock in South Australia
associated with the Acraman impact," Dr Grey said.
In a related study, Dr Calver found significant carbon isotope
changes mirrored Dr Grey's observations. Prof Walter has
also noted that patterns associated with the Acraman impact were
similar to those of mass-extinction and recovery events, and that
a large asteroid impact could have produced conditions
ideal for evolutionary change.
"Later impacts, like the 65 million year old Chixulub
collision in Mexico wiped out a diverse range of species,
including the dinosaurs," Dr Grey said. "But with the
Acraman impact, there were only a small number of species around
and the time to cause a mass extinction event.
"Most of the species that did survive were highly resilient,
and had the ability to remain dormant through the cosmic
winter that followed. When conditions improved, these species had
an advantage over their competitors and were able to
proliferate and diversify."
Dr Grey and her team have reasoned that the ensuing plankton
diversification must have played a vital role in the
subsequent development of the animals dependent on plankton as a
food source.
============
(2) METEORITES RAINED ON EARTH AFTER MASSIVE ASTEROID BREAKUP
Rice University, 8 May 2003
http://riceinfo.rice.edu/projects/reno/Newsrel/2003/20030508_meteorite.shtml
Office of News & Media Relations
DATE: May 8, 2003
CONTACT: Jade Boyd
PHONE: (713) 348-6778
EMAIL: jadeboyd@rice.edu
METEORITES RAINED ON EARTH AFTER MASSIVE ASTEROID BREAKUP
Geologists Find Meteorites 100 Times More Common in Wake of
Ancient Asteroid Collision
Using fossil meteorites and ancient limestone unearthed
throughout southern Sweden, marine geologists at Rice University
have discovered that a colossal collision in the asteroid belt
some 500 million years ago led to intense meteorite
strikes over the Earth's surface.
The research, which appears in this week's issue of Science
magazine, is based upon an analysis of fossil meteorites and
limestone samples from five Swedish quarries located as much as
310 miles (500 km.) apart. The limestone formed from sea
bottom sediments during a 2 million-year span about 480 million
years ago, sealing the intact meteorites, as well as
trace minerals from disintegrated meteorites, in a lithographic
time capsule.
"What we are doing is astronomy, but instead of looking up
at the stars, we are looking down into the Earth," said lead
researcher Birger Schmitz, who conducted his analysis during his
tenure as the Wiess Visiting Professor of Earth Science
at Rice. Schmitz is professor of marine geology at Göteborg
University in Sweden.
Meteorite activity on earth is relatively uniform today, with an
average of about one meteorite per year falling every
4,800 square miles (12,500 sq. km). The new study found a
100-fold increase in meteorite activity during the period when
the limestone was forming, a level of activity that was present
over the entire 96,500-square-mile (250,000 sq. km.)
search area.
Some 20 percent of the meteorites landing on Earth today are
remnants of a very large asteroid that planetary scientists
refer to as the "L-chondrite parent body." This
asteroid broke apart around 500 million years ago in what
scientists
believe is the largest collision that occurred in late solar
system history.
Schmitz and his colleagues looked for unique extraterrestrial
forms of the mineral chromite that are found only in
meteorites from the L-chondrite breakup. They found that all the
intact fossil meteorites in the Swedish limestone came
from the breakup. Moreover, they found matching concentrations of
silt and sand-sized grains of extraterrestrial
chromite in limestone from all five quarries, indicating that
meteorite activity following the breakup was occurring at
the same rate over the entire area.
The research helps explain why Schmitz and his colleagues at
Göteborg have been able to collect so many fossilized
meteorites from a single quarry near Kinnekulle, Sweden over the
past decade. Fossil meteorites embedded in stratified
rock are extremely rare. Only 55 have ever been recovered, and
Schmitz's group found 50 of those.
"It is true that we are lucky to be looking in just the
right place - a layer of lithified sediments that was forming on
the sea floor immediately after this massive collision,"
said Schmitz. "But on the other hand, we would never have
started looking there in the first place if the quarry workers
hadn't been finding the meteorites on a regular, yet
still rare, basis."
Until Schmitz's group started working with the quarry crew, the
fossilized meteorites were discarded because they
blemish the finished limestone. Schmitz believes it's possible
that similar concentrations of fossilized meteorites and
extraterrestrial chromite grains are present worldwide in
limestone that formed during the period following the asteroid
breakup. He recently got funding to look for evidence of this in
China, and he said there are South American sites that
are also favorable.
The research was sponsored by the National Geographic Society and
the Swedish Research Council.
============
(3) CAMERAS CAPTURE A 5-SECOND FIREBALL AND ITS METEORITE'S
SECRET
Andrew Yee <ayee@nova.astro.utoronto.ca>
[ http://www.nytimes.com/2003/05/13/science/space/13METE.html
]
Tuesday, May 13, 2003
Cameras Capture a 5-Second Fireball and Its Meteorite's Secrets
By HENRY FOUNTAIN
With meteorites, as with fine art, provenance counts for a lot.
But much more is known about a van Gogh or a Picasso,
say, than about most meteorites.
They come from space, sure, but beyond that little is certain.
Now, however, a meteorite has been found in southern Germany, and
a precise orbit has been determined for it. The
four-pound rock, named the Neuschwanstein for the Bavarian castle
near where it was found in July, is a remnant of a
five-second fireball captured on film three months earlier by a
network of tracking cameras in Central Europe.
This is the fourth time in more than 40 years that a meteorite
has been found after such cameras had photographed its
fireball, said Dr. Pavel Spurny, the coordinator of the European
Fireball Network and an astronomer at the Astronomical
Institute of the Academy of Sciences of the Czech Republic. What
is even more remarkable, Dr. Spurny said, is that the
orbit of this rock matches that of the first meteorite discovered
in this way, in 1959.
"The most unique fact is that two of these have the same
orbit," Dr. Spurny said.
It is not just coincidence, he added. The two are no doubt part
of a stream of rocks, probably fragments of one parent
asteroid in an elliptical orbit around the Sun that extends
nearly to Jupiter.
The Neuschwanstein fireball was photographed by 10 of his
network's 30 stations in Austria, the Czech Republic, Germany
and Slovakia. Each station has a fixed camera with a very
wide-angle lens and a rotating shutter that enables the
velocity of the meteor to be determined at various points as it
streaks across the sky. Taking the seven best images,
Dr. Spurny and others used simple triangulation to calculate the
trajectory.
They determined that the meteor first appeared at an altitude of
275,000 feet northeast of Innsbruck, Austria, entering
the atmosphere at an angle of almost 50 degrees, and traveled 50
miles northwest, disappearing at 52,000 feet. Its
initial speed was 13 miles a second, slowing to 1 1/2 miles a
second. Their findings are reported in the current issue
of Nature.
With this information, the researchers determined that the meteor
had an initial mass of 650 pounds and calculated the
trajectory of the "dark flight" of the estimated 30
pounds of rock that remained after the fireball had burned out.
The
meteorite was found was a few hundred yards
from the predicted impact area, and scientists assume other
fragments are in the general area.
Jack Drummond, a scientist at the Air Force's Starfire Optical
Range at Kirtland Air Force Base in Albuquerque, said the
Neuschwanstein find was a rare high point in observing fireballs.
"For 45 years or so, networks have been trying to do
this," Mr. Drummond said. While they have tracked plenty of
fireballs -- the European network records 40 to 50 a year -- the
goal of finding related meteorites has been elusive,
and two North American networks have been disbanded for lack of
financing.
"It's been very disappointing," he said.
Copyright 2003 The New York Times Company
==============
(4) METEOR'S FAMILY POSES PUZZLE
>From BBC News Online, 8 May 2003
http://news.bbc.co.uk/1/hi/sci/tech/3008063.stm
By Dr David Whitehouse
BBC News Online science editor
Researchers have analysed the path of a fireball that exploded
over central Europe in 2002, and shown the space rock
responsible came from an almost identical orbit to that of a
meteorite which fell to Earth in 1959.
But although the trajectories about the Sun of the two rocks
appear the same, the meteorites themselves are dissimilar
in composition.
This is leading researchers to reassess their understanding of
how meteoroids can group into streams as they circle our
star.
Such streams may contain a more varied collection of rocks than
previously believed.
Brighter than the Moon
The 2002 fall was of an object about 300 kilograms in mass that
had been orbiting the Sun between the Earth and the
asteroid belt for millions of years.
It came down to Earth on 6 April 2002.
As the rock plunged into the atmosphere, it became a very bright
fireball as it passed over western Austria and southern
Bavaria.
Far brighter than the full Moon, the fireball was seen by people
scattered all over central Europe. Residents in towns
and villages reported shaking ground, rattling windows and sounds
coming from the sky.
But in addition to these casual observations, the exploding
meteor's (or bolide's) trajectory was recorded by cameras
and various other sensors, making it unusually well documented
for such an event.
Dark and cooling
The data indicate the fireball's luminous trajectory was about 91
km long, starting at an altitude of 85 km about 10 km
east-northeast of Innsbruck, Austria, terminating at an altitude
of 16 km, about 20 km east of Garmisch-Partenkirchen,
Germany.
It entered the atmosphere at a speed of 21 km per second and
decelerated to 2.4 km per second, by which time the
ablation of its surface by atmospheric friction ceased, and it
fell to Earth dark and cooling.
Researchers, from the Czech Republic and Germany, identified a
"footprint" about 800 metres wide and several km long
as
the most probable location for any fragments from the bolide to
be found.
Remarkably, a piece was recovered in a mountainous area on 14
July.
And then the story became more intriguing.
Non-identical twins
The data on the object's fall enabled its orbit around the Sun to
be determined. It is rare to have a physical specimen
and an accurate orbit; there are but a handful of examples.
Curiously, the meteorite had come out of an almost identical
orbit to that of a space rock which fell to Earth in 1959.
It, too, had extensive data available about it. "This paired
meteorite fall is probably not a coincidence," say the
researchers.
But although the two meteorites might be from the same stream
orbiting the Sun, they are not identical. Their
compositions and the time they had spent wandering space are
different.
The effects of cosmic rays on rocks in space enable astronomers
to determine roughly how long an object has been in
orbit. The 2002 meteorite had been in space for 48 million years
but the 1959 object only 12 million years.
The tentative explanation proposed by the researchers is that
streams of meteoroids may be more varied than was
previously thought, as it seems unlikely that both rocks came
from the same parent body.
The research is published in the journal Nature.
Copyright 2003, BBC
===========
(5) THE NEUSCHWANSTEIN METEORITE
Nature 423, 151 - 153 (2003); doi:10.1038/nature01592
http://info.nature.com/cgi-bin24/DM/y/ehj0BfHpg0Ch0Qf0AQ
Photographic observations of Neuschwanstein, a second meteorite
from the orbit of the Píbram chondrite
PAVEL SPURNÝ, JÜRGEN OBERST & DIETER HEINLEIN
Correspondence and requests for materials should be addressed to
P.S.
(spurny@asu.cas.cz).
Photographic observations of meteoroids passing through the
atmosphere provide information about the population of
interplanetary bodies in the Earth's vicinity in the size range
from 0.1 m to several metres. It is extremely rare that
any of these meteoroids survives atmospheric entry to be
recovered as a meteorite on the ground. Píbram was the first
meteorite (an ordinary chondrite) with a photographically
determined orbit; it fell on 7 April 1959 (ref. 1). Here we
report the fourth meteorite fall to be captured by camera
networks. We determined the atmospheric trajectory and
pre-atmospheric orbit of the object from the photographic
records. One 1.75-kg meteorite - named Neuschwanstein and
classified as an enstatite chondrite - was recovered within the
predicted impact area. The bolide's heliocentric orbit
is exceptional as it is almost identical to the orbit of Píbram,
suggesting that we have discovered a 'stream' of
meteoritic objects in an Earth-crossing orbit. The chemical
classifications and cosmic-ray exposure ages of the two
meteorites are quite different, however, which implies a
heterogeneous stream.
© 2003 Nature Publishing Group
=============
(6) TWO-WAY ASTEROID TRIP TAKES OFF
Astrobiology Magazine, 12 May 2003
http://www.astrobio.net/news/article458.html
A Japanese rocket lifted off Friday on the world's first mission
to collect samples from the surface of an asteroid,
part of a four-year journey covering nearly 400 million miles.
Taking off from Kagoshima in southern Japan on its 22 month
outbound trip, the Muses-C space probe is scheduled to visit
the 1998 SF36 asteroid, 186 million miles from Earth, and bring
back a single gram of rock in four years' time.
'Asteroids are known as the fossils of the solar system,' said
mission leader Junichiro Kawaguchi of Japan's Institute
of Space and Astronautical Science. This body designated
1998SF36, like other small objects in the solar system, is
believed to act as a record of aspects of the state of the early
solar system and this exciting mission will return
fragments of the asteroid's surface to the Earth for detailed
analysis. The MUSES-C spacecraft will approach and stay
near the asteroid for about five months
'By examining them, you can find out what substances made up the
solar system, including Earth, in the distant past.'The
asteroid belt is a doughnut-shaped area that measures some 175
million miles wide and 50 million miles thick. The
material in the belt travels at speeds up to 45,000 mph and
ranges in size from dust particles to rock chunks as big as
Alaska. [Pioneer 10 was the first spacecraft to pass through the
asteroid belt, considered a spectacular achievement,
and then headed on toward Jupiter.]
If successful, the "Muses-C" will be the first probe to
make a two-way trip to an asteroid. A NASA probe collected data
for two weeks from the surface of the Manhattan-sized asteroid
Eros in 2001, but it was not designed to return with
samples.
The unmanned Muses-C was launched Friday atop a $60 million M-5
rocket from the Kagoshima Space Center on the island of
Kyushu in southern Japan.
Iwao Hashizume, an Institute of Space and Astronautical Science
spokesman, said the Muses-C had reached its orbit
heading away from Earth at 6.9 miles per second. Its solar energy
panels had unfolded and its sample-collecting arm had
responded to tests, Hashizume said. Total mission time is about
4.5 years.
Propelling MUSES-C during its four-year space journey are ion
engines, also a key technology for the spacecraft. Instead
of liquefied fuel, the engines use xenon gas and ionize its
atoms. Thrust is generated by expelling these ions at high
speed with the help of a strong electric field. It will be the
first attempt in the world to use ion engines as the main
propellant, although a number of test probes including the Deep
Space probe have pioneered the small, but steady,
microwave push given by charging particles. The propellant Xenon
is first ionized by the microwave, followed by
acceleration with high voltage to generate the thrust. Ion
engines, as well as many other types of electric propulsion,
have a very high efficiency when compared to chemical propulsion
methods.
Shaped like a rugby ball some 500 meters (yards) long, the target
asteroid is twice as far away as the sun, but still
one of the nearest to Earth.It is one of numerous asteroids
between Mars and Jupiter and is on an elliptical orbit that
comes close to Earth and Mars.
Muses-C is set to land on the asteroid's surface and fire a small
projectile into the crust, scooping up the resulting
rock fragments. Even a tiny amount will be sufficient for
research purposes, Kawaguchi said. The procedure requires the
spacecraft to land a "sampler horn" on the asteroid
surface. A metal bullet weighing 5 to 10 grams will be fired from
inside the horn into the surface at a speed of about 300 meters
per second.
The bullet will smash into the surface, sending fragments flying
about. They will be captured by the horn and funneled
into a sample container. Just after samling, the spacecraft will
lift off immediately. The time for each of the contacts
with the asteroid surface is planned to be on the order of 1
second.
Because of the asteroid's small mass and gravity, any gentle push
off would send the space probe back off the surface.
Such low escape velocities (30 cm/s) mean that you don't so much
land on the asteroid surface as "dock" with it - and
any sort of digging tool will need a strong anchor otherwise you
may end up just pushing the spacecraft away without the
spade actually going into the material. So mission planners will
fire a small bullet and vacuum up any fragments into a
horn-shaped collector.
On return to Earth's atmosphere around June 2007, the sample
container is designed to break away from the probe and
parachute back to land in the Australian desert, or Outback.
After being fully decelerated by atmospheric drag, the
capsule deploys a parachute for soft-landing. The capsule with
the asteroid sample is retrieved by localizing its
position from ground stations that track a beacon signal from the
capsule.
Scientists say they hope examinations of particles from the
asteroid's surface will provide clues on how the planetoid
was created.
'Bringing back a sample is an extremely difficult proposition,'
Kawaguchi said, when asked about the mission's chances
of success. If successful, it will be the first sample collected
from an asteroid, and the first of a celestial body
following the moon stone sampling by the U.S. Apollo missions
from 1969 to 1972.
What's Next
In the next 5 or so years, there will be no fewer than five
encounters of spacecraft with comets and asteroids. All the
following missions are fully funded, though only not all have
already been launched (the others will follow in 2003 to
2004):
2001 Sept. 22 Comet Borrelly Deep Space One (simple
flyby)
2003 Nov. 12 Comet Encke CONTOUR (simple flyby)
2004 Jan. 1 Comet Wild 2 Stardust (coma
sample return)
2005 July 3 Comet Tempel 1 Deep Impact
(big mass impact)
2005
Sept.
Asteroid 1998 SF36 Muses-C (sample return)
===========
(7) SCIENTISTS FORESEE THE END OF THE EARTH
Space.com, 12 May 2003
http://www.msnbc.com/news/912674.asp
Authors say our planet's long-term fate is to 'fry and dry'
May 12 - In 2000, paleontologist Peter D. Ward and
astronomer Donald Brownlee argued persuasively in their book
"Rare
Earth" that life in all its complexity found on Earth is
most likely a cosmic aberration, a unique circumstance that -
if their theory is true - dashes the hopes of sci-fi fans and
extraterrestrial hunters everywhere. This year, the
authors returned with an analysis of Earth's far-flung future
that is as bleak as humanity's chances of meeting E.T.s,
intelligent or otherwise.
"THE LIFE and Death of Planet Earth" sees Earth
slipping towards another ice age with dwindling natural
resources,
drastic environmental changes and eventually a suffocating death.
Perfect for summer reading, we say!
Co-author Donald Brownlee took the time to answer a few of
Space.com's questions about his latest book.
Space.com: The bottom line: Will we ultimately freeze, fry or
just dry out?
Brownlee: We may "freeze" again in the future as we
have in the past. This could be as severe as another
"Snowball
Earth" episode, or it could just be a continuation of
glacial-interglacial cycles. On the long term, the fate is
"fry
and dry." The sun continuously gets hotter, and its heat
ultimately melts the earth's surface - and worse.
In the grand scheme, will human activity alter Earth's ultimate
fate?
Humans have great effects on the short term (global warming,
species extinction, etc.) but it is not likely that we can
play an significant role in the main events that will change
Earth on long time scales. These events include the merging
of the continents (again), decline of CO2 below levels required
to support plant life, the loss of the oceans to space
and our planet being swallowed by the sun. Human intervention on
these effects would require engineering on a incredible
scale. The ultimate fate of Earth is determined by the
ever-increasing brightness of the sun - a natural and unstoppable
process.
Is there anything we can do to escape Earth's fate? Maybe move
it, or move us?
In the book we discuss ideas for moving Earth outwards as the sun
gets brighter. As difficult as it seems, this is
perhaps more likely than human migration to other planetary
systems. It is the natural cycle of planets with life that
they are ultimately are done in by their
"life-supporting" star. Habitable planets have to form
close to a star to have
the right conditions to have surface water. Over time, all stars
become brighter and the "habitable zone" moves outward,
leaving the planet too hot for surface water.
Yesterday was pretty tough here on Earth. Tomorrow probably won't
be a picnic. Why worry about what's going to happen in
a few billion years?
We should not "worry" about things that happen millions
of years beyond our lifetimes, but it is important that we know
how nature (and our planet) works. We benefit greatly from
knowledge of nature and natural processes. Even simply
knowing that the earth is not flat and that we are not at the
center of the universe greatly benefits our daily lives
(GPS, weather satellites, etc.) in an enormous number of ways. By
understanding the full cycle of planets, how they are
born, evolve and ultimately die, we can better understand and
appreciated our role in the cosmos.
What are the advantages to being able to predict the earth's end?
For a person with a terminal disease, diagnosis is the first step
to extending life, and improving its quality. The same
is true for our planet. Knowing our problems gives us the ability
to attempt a cure, or at least to put off the various
ends of the earth, and of humanity.
Two variables, above all others, will control the destiny not
only of life on Earth, but also, ultimately, of the planet
itself. The first is the amount of carbon dioxide in the
atmosphere. This greenhouse gas helps regulate our world's
temperature, and our planet is extraordinary in the systems it
has to balance that greenhouse gas with incoming
radiation.
The second system, and ultimately a far more important variable,
is the amount of solar energy hitting our planet. The
sun's output level is changing over time. Mathematical modeling
allows us to predict what these levels will be in the
far future, and what their effects will be - and it doesn't look
good.
What most upsets you about science or scientists?
I love science and think that it is critical to our well being
and future. Perhaps the most upsetting thing is the level
of scientific illiteracy in the United States. My son in college
is required to do four semesters on philosophy but only
one on science. Everyone depends on science and understanding the
natural world, but it is not stressed in schools. Only
a tiny fraction of high school students take physics - the most
fundamental of all of the sciences.
What is the most beautiful aspect to space?
Much of astronomy is beautiful images of planets, moons,
asteroids, comets, sections of meteorites and lunar rocks,
microscope images of extraterrestrial material and fabulous
telescope images of many astronomical objects outside the
solar system.
If you controlled a $1 billion foundation, what research effort
would you fund?
A sample return mission from a comet.
Why should we spend money on space exploration over research into
deadly diseases?
We can and should do both. Advances in science and understanding
of nature are not always made by planned and directed
programs such as the "war on cancer." History has shown
that many great breakthroughs (i.e., X-rays and even the
Internet) come come from unexpected directions. Understanding the
universe was the historical foundation of modern
science, and it is still the leading edge of knowledge of the
fundamental workings of nature. The recently announced
results from the WMAP spacecraft are some of the most fundamental
discoveries of our time.
What is the most vexing question in modern science?
The most vexing question will certainly depend on whom you ask.
Personally, I would like to know how Earthlike planets
form and what fraction are fully Earthlike in the sense that that
could support animal life. My No. 1 near-term question
is whether there is or was life in the solar system other than on
earth. My guess is yes.
"The Life and Death of Planet Earth: How the New Science of
Astrobiology Charts the Ultimate Fate of Our World" by Peter
D. Ward and Donald Brownlee. Published by Times Books, January
2003. $25.00 /$36.95 Canadian; 0-8050-6781-7.
© 2003 Space.com. All rights reserved.
===========
(8) WHAT DO YOU THINK HUMANITY'S FATE ON EARTH WILL BE ?
MSNBC.com, 12 May 2003
http://www.msnbc.com/news/912674.asp
* 29156 responses
Humans will settle beyond Earth and survive even if the planet
becomes uninhabitable.
25%
Humanity will pass away along with the planet.
8%
The planet will outlast our species.
26%
The world will end in a supernatural, transformational event like
the Second Coming.
35%
None of the above.
6%
============
(9) REVISITING THE END OF THE WORLD
Alan Boyle's Cosmic Log, 14 May 2003
http://www.msnbc.com/news/750150.asp?0si=-
How will the world end? In fire or in ice? In the long run, the
authors of "The Life and Death of Planet Earth" are
siding with Robert Frost and putting their money on fire - more
precisely, a "fry and dry" scenario. But it could be
500
million years or more before we find out if they were right or
not.
I referred to the book a couple of months ago, but this week's
Space.com interview with one of the authors, University
of Washington astronomer Don Brownlee, sparked a new wave of
feedback:
Violet: "After reading your article on the 'Life and Death
of Planet Earth' - the questions answered by [paleontologist
Peter] Ward - I think we are all pessimists. Not just him ... all
teachers stress the grim end of the planet. None of my
teachers had anything to say that something good was going to
happen. The only good thing is that we are 'smart,'
confused and curious .. Which basically keeps up some sort of
optimism. Could it be that religion is the only optimism
here?"
William McDill: "... Each cultural cycle ended in ruin and
catastrophe, but the next cultural birth rebuilt and moved
on. Each cycle saw wider expanse of influence, wider powers of
organization. Each cycle showed more power to affect the
physical environment.
"I have to believe that four or so cycles from now - A.D.
9000, figure 1,200 years per civilization, 400 years recovery
and rebirth - a civilization will arise which can a) perform
economical space travel (as an analog to the difference
between Leif Erickson and Vasco da Gama) or have the power to
literally make the earth move.
"Human intelligence is unique and is at least as significant
as the four chambered heart, the hard-shelled egg, lungs or
the spine. Each of the previous physical innovations created
subphyla which lasted hundreds of millions of years. I
would think that a betting man would give us humans a good shot
to reach 100 million."
Roger: "There is no way I can imagine mankind being around 5
million years from now. Or, for that matter, planet Earth
as we know it today. The sad truth is we, as humans, are much too
violent and are on a mission to self-destruct. I think
the end is much closer then we want to admit or even consider. It
scares me to think about the total power some nations
hold at their fingertips. It also saddens me to think about the
destruction we humans have already done to this
wonderful planet, and to merely shrug it off as progress shows we
have no respect for life."
Lynda: "Shame on us if we can't get into space and terraform
some piece of rock with our knowledge and survive
indefinitely by moving when it is necessary."
Harvey: "The planet Venus seems to offer a glimpse into the
eventual fate of our own planet, while at the same time,
Mars would seem to offer a seedbed for prolonging forms of life
as we know it to be. If indeed our sun will expand and
temperatures will increase, causing Earth to become uninhabitable
- which seems to be the presently most accepted theory
by the scientific community today - then I would think that the
equation to solve this problem rests in technology plus
resources vs. time.
"If we are firm in the belief that this is our planet's fate
and we will not become extinct through some other means,
then I should think that some of our more brilliant minds should
be doing studies along this line. ..."
DEEP DOOMSDAY
Today's "Modest Proposal" to send a probe to Earth's
core puts a different spin on the "end of the earth"
debate: After
all, the concept is intertwined with the plot line of "The
Core," a date-with-doomsday movie that came out just a few
weeks ago.
Most of the people who responded to the report's unscientific
Live Vote think such a mission is either totally
unworkable or too dangerous to attempt. What do you think?
A colleague of mine at MSNBC.com, Mark Stevenson, notes that
"The Core" isn't the first film built around a
deep-doom
plot: The 1965 movie "Crack in the Earth," starring
Dana Andrews, is your typical mad-Cold-War-scientist saga about
blowing up the planet from the inside. There's a long plot
description and tongue-in-cheek analysis on a Web site called
"And You Call Yourself a Scientist!" I haven't seen the
flick yet, but I already love the dialogue:
Layperson: What if the crack keeps going - right around the
world? What happens then?
Scientist: Where the land masses split the oceans will be sucked
in, and the colossal pressure generated by the steam
will rip the earth apart - and destroy it.
Layperson: You mean - the world will come to an end!?
Scientist: The world as we know it, yes. As a cloud of astral
dust, it will continue to move within the solar system.
============================
* LETTERS TO THE MODERATOR *
============================
(10) IMPACT PAPERS IN ASTROBIOLOGY JOURNAL
Michael Paine <mpaine@tpg.com.au>
Dear Benny
The following articles are currently free to view.
regards
Michael Paine
Astrobiology, a journal from Mary Ann Liebert, Inc.,
Volume 3, Number 1 is now available online via the Ingenta Select
service, and contains the
following articles:
Rubey Colloquium Paper
Articles
Bombardment of the Hadean Earth: Wholesome or Deleterious?
Graham Ryder
Spherule Beds 3.47-3.24 Billion Years Old in the Barberton
Greenstone Belt, South Africa: A Record of Large Meteorite
Impacts and Their Influence on Early Crustal and Biological
Evolution
Donald R. Lowe; Gary R. Byerly; Frank T. Kyte; Alexander
Shukolyukov; Frank Asaro; Alexandra Krull
Petrographic Criteria for Recognizing Certain Types of Impact
Spherules in Well-Preserved Precambrian Successions
Bruce M. Simonson
Impact at the Permo-Triassic Boundary: A Critical Evaluation
Douglas H. Erwin
Fullerenes and Interplanetary Dust at the Permian-Triassic
Boundary
Robert J. Poreda; Luann Becker
A Search for Soot from Global Wildfires in Central Pacific
Cretaceous-Tertiary Boundary and Other Extinction and Impact
Horizon Sediments Rubey Colloquium Paper
Wendy S. Wolbach; Susanna Widicus; Frank T. Kyte
Chicxulub and Climate: Radiative Perturbations of Impact-Produced
S-Bearing Gases
Elisabetta Pierazzo; Andrea N. Hahmann; Lisa C. Sloan
Cenozoic Bolide Impacts and Biotic Change in North American
Mammals
John Alroy
Environmental Consequences of Impact Cratering Events as a
Function of Ambient Conditions on Earth
David A. Kring
Comparing the Evidence Relevant to Impact and Flood Basalt at
Times of Major Mass Extinctions
Walter Alvarez
Large Aerial Bursts: An Important Class of Terrestrial
Accretionary Events
John T. Wasson
The Impact Crater as a Habitat: Effects of Impact Processing of
Target Materials
Charles S. Cockell; Gordon R. Osinski; Pascal Lee
Impacts and Evolution: Future Prospects
David Morrison
Exchange of Meteorites (and Life?) Between Stellar Systems
H. J. Melosh
To view this issue online, please go to:
http://www.ingentaselect.com/rpsv/cw/mal/15311074/v3n1/contp1-1.htm
===============
(11) HOT-HOTSPOTS
Hermann Burchard <burchar@math.okstate.edu>
Dear Benny,
from SCIENCE Magazine online two articles (Foulger & Natland
vs. DePaolo & Manga, see below) desperately seeking hotspot
origins. Of course, neither mentions that cometary impacts just
MIGHT have something to do with it. Two opposing views
are promoted here, however, one [Foulger &
Natland] correctly asserting
"that `hotspot' volcanism is not very hot and is
..shallow-source"
but going on to incorrectly state it's a "by-product of
plate tectonics."
Indeed, there are no deep mantle or CMB, core-mantle boundary,
phenomena at play. However, the only connection with
plate tectonics is that impacts can break plates and lead to
triple-point faults, as in the case of the N Atlantic
splitting open at the time of the Triassic/Jurassic extinction
boundary and the eruption of CAMP basalts.
The other article [DePaolo and Manga] claims improved seismic
tomography calculations will demonstrate CMB origins:
"Direct evidence for mantle plumes will require
seismic imaging at
resolution sufficiently high to detect narrow
conduit-like structures
in the lower mantle. The present lateral
resolution of 1000 km that is
achieved with standard techniques is too poor
for this task. However,
preliminary results.. suggest that image
resolution can be improved
using alternative data reduction approaches,
and that the deep roots
of mantle plumes can already be resolved with
available data.."
The last death-throws of a doomed theory.
Cheers,
Hermann G. W. Burchard
http://www.sciencemag.org/cgi/content/short/300/5621/921
============
(12) MULTIPLE IMPACT EVIDENCE AT CHICXULUB
Hermann Burchard <burchar@math.okstate.edu>
Dear Benny,
previously, CCNet reported on multiple impact evidence at
Chicxulub. WELT AM SONNTAG quotes Wolfgang Stinnesbeck, of
Karlsruhe University, about this. He is a collaborator of
Gerta Keller of Princeton, who has contributed related items
to CCNet. Drilling results seem to negate
earlier estimates of size and the sequence deposits of impact
ejecta in various localities in Mexico is also
contradictory to the Chicxulub impactor having been the main
Killer.
http://www.wams.de/data/2003/05/04/83608.html
Also see an abstract of one of the relevant papers:
Keller, G., Adatte, T., Stinnesbeck, W., Stueben, D., Kramar, U.
&
Harting, M., "The K/T Transition at Yaxcopoil-1
drillhole." Geophysical
Research Abstracts, Vol. 5, 14415, European Geophysical Society
(2003)
http://www.cosis.net/members/meetings/special_interest/programme_view.php?sp_id=1&pg_id=24
Cheers,
Hermann Burchard
============
(13) AND FINALLY: "MASTERS OF THE UNIVERSE" - AN
ANTIDOTE TO CARTER'S DOOSMDAY ARGUMENT AND SECULAR
TECHNO-PESSIMISM
Reason Magazine, May 1998
http://reason.com/9801/bk.silber.shtml
By Kenneth Silber
Visions: How Science Will Revolutionize the 21st Century, by
Michio Kaku, New York: Anchor Books/Doubleday, 403 pages,
$24.95
Visions begins on a note of arrogance. Unlike previous efforts to
chart the future of technology, Michio Kaku assures
us, his predictions are likely to be correct. As science
approaches a full understanding of the laws of nature, a
scientific consensus is emerging about where technology is headed
and on what timetable. This book, Kaku asserts,
reflects that consensus.
Baloney. What is remarkable about many of the advanced
technologies Kaku discusses--artificial intelligence, genetic
engineering, nuclear fusion, electric cars--is the distinct lack
of scientific unanimity about their potential. For
every physicist who says that fusion is "the energy of the
future," there's another who replies, "Yes--and it
always
will be." Even when the experts are in general agreement--as
they once were about the infeasibility of cloning an adult
sheep--consensus has hardly proven a guarantee of predictive
accuracy.
Nonetheless, Kaku, a theoretical physicist and high-profile
popularizer of science, has written an absorbing book,
filled with thoughtful speculations about the 21st century and
beyond. Visions sketches what might emerge from three
20th-century scientific upheavals: the "computer
revolution," the "bio-molecular revolution," and
the "quantum
revolution." These revolutions are interconnected, as Kaku
notes; discovery of the DNA double helix, for example, relied
on X-ray crystallography, a technique derived from quantum
physics. Such linkages, he expects, will take on growing
importance in the next century, in the form of DNA-based
computers and other hybrid technologies.
Visions provides an intriguing (and explicit) rejoinder to The
End of Science, the 1996 book in which journalist John
Horgan argued that the era of scientific discovery is sputtering
out in disappointment and confusion. Similar to Horgan
(but unlike eminent scientists such as Roger Penrose and Freeman
Dyson), Kaku believes that breakthrough insights into
nature's workings, such as evolution and relativity, are now
mainly things of the past. But where Horgan detected
intellectual drift and technological stagnation, Kaku sees
something very different: The age of discovery is giving way
to the age of mastery. Having learned the universe's rules,
humans are finally ready to become full-fledged players in
the game.
The quantum, biomolecular, and computer revolutions, in other
words, are enabling us to be "choreographers of matter,
life, and intelligence," no longer mere passive observers of
nature's dance. Yet even while taking this expansive view
of technology's potential, Kaku is adept at recognizing
technological hurdles and limits.
Computing power, Kaku expects, will become increasingly cheap and
ubiquitous in the next two decades, manifested in such
products as wearable computers, smart cars, and digital scrap
paper. Helpful (but sometimes annoying) "intelligent
agents" will sort your e-mail, update your schedule, and
remind you to watch your diet. But before long, Kaku notes,
chip making will bump up against the physical limits of silicon,
and further progress will depend on the development of
holographic memory, organic processors, quantum transistors, and
other exotic technologies.
After 2020, Kaku predicts, the first glimmerings of true
artificial intelligence will appear, as computers acquire
common sense and as the Internet evolves into something similar
to the "magic mirror" that imparts wisdom in fairy
tales. After 2050, robots endowed with some degree of
consciousness and self-awareness may roam the earth. Might
humanity eventually be enslaved or slaughtered by its robotic
creations? Kaku closes his discussion of artificial
intelligence with an overview of the built-in safeguards that
should be devised to prevent such an outcome.
Biotechnology also will make vast strides in the early 21st
century, according to Kaku. By 2020, the genetic
underpinnings of many hereditary diseases will be understood, and
entire classes of cancer will be curable. People will
own CD-ROMs containing their own personal DNA codes. Between 2020
and 2050, genetic research will see slower progress,
as scientists grapple with the intricacies of gene function and
protein folding. During this period, however, it will
become possible to grow new vital organs in the lab, perhaps
extending the human life span by decades.
After the century's midpoint, Kaku writes, "we may be able
to manipulate life itself." Yet he is impenetra-bly vague
about what this means. More interesting is Kaku's discussion of
feats that probably lie beyond biotech's reach.
Performing major design changes on human beings--say, growing
wings on a person's back, in Kaku's whimsical example--is
unlikely to be feasible even in the late 21st century. Consider
the obstacles involved: The genes that initiate wing
formation in a bird or insect may do nothing in a human (or may
activate homologous organs, such as arms); these genes
would have to be altered to allow a wingspan of some 20 feet; and
the human's entire genome would have to be transformed
to create the lighter bones and stronger muscles required for
flight.
Surveying the "quantum future," Kaku assesses a broad
range of possibilities for manipulating matter and developing new
sources of energy. Electric cars and magnetic-levitation trains
are emerging as viable forms of transportation, he
argues, and solar power is poised to become a leading energy
source. Room-temperature superconductors and microscopic
lasers may find numerous industrial applications.
Nanotechnology's molecule-sized machines are of uncertain
feasibility,
Kaku notes, but dust-sized sensors and motors will be used widely
in the coming decades. Some other staples of science
fiction, such as force fields and portable ray guns, appear to be
incompatible with known laws of physics, he adds.
Space technology will make steady, if unspectacular, progress in
the next few decades, according to Visions. Kaku is
dismissive of the notion of a manned mission to Mars in the early
21st century, basing his argument on exorbitant cost
estimates now widely regarded as erroneous. Yet after 2020, he
emphasizes, astronomical instruments may be sensitive
enough to detect Earth-like planets in other solar systems. The
century's latter half may see ambitious efforts to
develop fusion-powered interstellar rocket ships. Antimatter
engines loom as an intriguing prospect sometime beyond
2100.
Kaku's social and political asides are less imaginative than his
technological speculations. He argues, plausibly but
predictably, that the economic strength of nations in the 21st
century will depend on their technological prowess. In
chapters devoted to "second thoughts," he presents grim
scenarios of "information ghettos" and bioengineered
germ
weapons; his solutions are unremarkable generalities about
education and international cooperation. Some of Kaku's
political pronouncements are mere clichés. Discussing the
nation-state's future, he writes, "As John Lennon said in
his
song `Imagine,' perhaps it's not hard to imagine a world without
nations."
Might a public backlash against technology derail much of the
progress forecast in this book? The history of advanced
technologies in the 20th century--nuclear energy comes to
mind--indicates that not everything that is technically
feasible will end up receiving political and social acceptance.
Certainly, the 21st century's "choreographers of matter,
life, and intelligence" will face their share of protest
movements and hostile regulators. Visions, however, has little
to say about such matters.
That is unfortunate, since Kaku's own experience might have
provided an interesting perspective. A longtime antinuclear
activist, he was a leading figure in the 1997 protest campaign
against the Cassini space probe, a plutonium-using
scientific mission to Saturn. Critics of the anti-Cassini
movement, including me, argued that the campaign relied on
gross exaggerations of the mission's risks and that the broad
opposition to "nukes in space" threatened to cripple
space
exploration. In addressing the uncertainties of technological
change, Kaku the author might have taken some tips from
Kaku the activist.
Yet even if technology follows a more unpredictable--and
politically volatile--path than the one glimpsed in Visions,
the book's strengths readily outweigh its weaknesses. Kaku's
predictions are intelligent and thought-provoking, and his
technological optimism never veers into an unconvincing
techno-utopianism. Moreover, no one can accuse him of thinking
small. Looking beyond the 21st century, Kaku sketches out a bold
future of galactic colonization and more.
Drawing upon categories devised by Russian astronomer Nikolai
Kardashev, Kaku sees technological civilizations advancing
through several phases: Types I, II, and III. Type I refers to a
global civilization, the masters of a single planet. A
Type II civilization utilizes the resources of an entire solar
system; such a society might even build a vast shell or
"Dyson sphere" around its star. A Type III civilization
operates on a galactic scale, occupying numerous solar systems.
In this scheme of things, humanity is currently a backward
society, or Type 0, but is on the verge of attaining Type I
status.
Becoming a Type II civilization will take many centuries,
according to Kaku, and achieving galactic Type III status
requires many millennia. But it's worth the effort: Civilizations
of Types II and III are invulnerable to asteroid
impacts, supernova explosions, and other natural disasters.
Toward the book's end, Kaku launches into a discussion of
wormholes, superstrings, and other exotica of modern
cosmology. After billions of years, even galactic civilizations
are doomed, as the universe freezes in a Big Chill or
collapses in a Big Crunch. But on the book's last page a new
category is introduced: the Type IV civilization, masters
of space and time. Such beings might be able to build tunnels to
parallel universes. Here, then, is Kaku's ultimate
statement of technological optimism: Intelligent life might
survive the end of our universe.
Kenneth Silber writes about science, technology, and economics.
Copyright 2003, Reason Magazine
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