CCNet 125/2000 - 1 December 2000

"Hudson is more interested in the positive potential of these
asteroids than doomsday predictions. 'Scientifically, these are very
exciting because they are treasure troves of raw materials. As we work on
the space station and move towards the colonization of space, they could
provide us with many resources. I like to think of them in a positive light
because of their potential to us.'"
   -- Scott Hudson, Daily Evergreen, 27 November 2000

"The Earth is a much bigger target than the moon. Earth would have
been bombarded by at least 10 times as many impact events as the moon,
and these impact cratering processes are immense. The Chixculub
crater that we identified, which is related to the mass extinction of
dinosaurs and other life 65 million years ago, is puny by comparison to the
scheme we are talking about. Here we are talking about impacts that
are 10 times larger, impacts that blasted craters rim-to-rim the size
of continents on Earth today."
-- David A. Kring, University of Arizona, 30 November 2000

    Andrew Yee <>

    BBC New Online, 30 November 2000

    Exite News, 27 November 2000

    Andrew Yee <>

    Michael Paine <>

    Scientific American, December 2000

    Ron Baalke <>

    Andrew Yee <>

    Andrew Yee <>


From Andrew Yee <>

News Services
University of Arizona
Tucson, Arizona
Contact Information:
Barbara Cohen (UT), 865-974-6024,
Timothy D. Swindle (UA), 520-626-5741,
David A. Kring (UA), 520-621-2024,
Nov 30, 2000
Lunar Meteorite Ages Strongly Support 'Lunar Cataclysm'
By Lori Stiles
Lunar meteorite ages present new, strong evidence for the "lunar cataclysm,"
a 20-to-200 million-year episode of intense bombardment of the moon and the
Earth at 3.9 billion years ago -- when the first evidence of life appeared
on Earth, planetary scientists report in the Dec. 1 issue of Science.
Whether or not there was life on Earth at the beginning of the bombardment,
such cataclysmic pounding would have enormous consequences for life on this
planet, whether by destroying existing life or organic fragments or by
delivering molecules and creating conditions suitable for life, the
researchers add.
Barbara Cohen of the University of Tennessee -- Knoxville analyzed the lunar
meteorite ages for her dissertation research at the University of Arizona in
Tucson. Timothy D. Swindle and David A. Kring of the UA collaborated on the
study and are co-authors on the Science article. Swindle supervised Cohen's
research. Kring is an expert in impact cratering and one of the discoverers
of the K/T boundary Chicxulub impact site.
Moon rocks returned by the Apollo and Luna missions in the 1970s suggested
that Earth's moon was blasted in a maelstrom of solar system debris at 3.9
billion years ago. A great swarm of asteroids or comets pounded the lunar
surface during a brief pulse in geologic time, melting rocks, excavating
vast craters and resurfacing Earth's natural satellite.
But for safety and communications reasons, both manned and robotic
spacecraft were landed near the moon's equator, on the side facing Earth. No
one could say if just this part of the moon or the entire moon had been
Cohen, Swindle and Kring bring the most significant data in nearly 30 years
to bear on this question. They used an argon-argon dating technique in
analyzing impact melt ages of four lunar meteorites -- rocks ejected at
random from the moon's surface and that landed on Earth after a million or
so years in space. They find from the ages of the "clasts," or melted rock
in the breccia meteorites that all of the moon was bombarded 3.9 billion
years ago, a true global lunar cataclysm.
Further, although the moon may have been bombarded before 3.9 billion years
ago, the scientists find no evidence for it. If there were no earlier
bombardment, scientists must jettison theoretical models that assume a
steady falloff in the lunar and inner solar system cratering rate through
"Given the model of what was going on in the solar system, there is no
obvious reason why you should suddenly have a bunch of things banging on the
moon 4 billion years ago and not 4.2 billion years ago," Swindle said.
But the most dramatic implication is what happened during this event on
"The Earth is a much bigger target than the moon, " said Kring, associate
professor at the UA Lunar and Planetary Lab. "Earth would have been
bombarded by at least 10 times as many impact events as the moon, and these
impact cratering processes are immense. The Chixculub crater that
we identified, which is related to the mass extinction of dinosaurs and
other life 65 million years ago, is puny by comparison to the scheme we are
talking about. Here we are talking about impacts that are 10 times larger,
impacts that blasted craters rim-to-rim the size of continents on Earth
"The bombardment would have charged the atmosphere with silicate vapor and
vaporized the oceans, so if there was life on Earth before the bombardment,
the question is what, if anything, survived," Swindle said. Perhaps some
genetically primitive "extremeophiles" survived, he added. This kind of life
is found on Earth today deep in rocks or living at the ocean vents.
What did the bombarding? More likely asteroids than comets, based on some
evidence from meteoritic trace constituents involved in the impacts and on
other studies on what was happening at the time in the asteroid belt, Kring
"When we first started this research, the goal was to find something older
than 3.9 billion years," Cohen said. "We were very surprised at the evidence
presented by seven different impacts, which pointed to 3.9 billion years." 
Swindle said, "Going into this study, I would have bet that we wouldn't have
found these results. I would have bet that we would have seen impacts
earlier than 3.9 billion years ago."
Kring said, "I've quit being surprised at what impact cratering processes
can do."
Kring, director of the Lunar and Planetary Lab's Space Imagery Center, has
just added new web pages on impact cratering, the lunar cataclysm and origin
of life, the moon and lunar meteorites at the Space Imagery Center web
(Bill Dockery, UT News Services, 865-974-2225,, is also a
media contact on this story.)
Related Links
[ ]
[Image 1]
The moon's crater, Tycho, taken with NASA's Lunar Orbiter 5 spacecraft
medium-resolution camera (1966-67).
[Image 2]
Barbara Cohen holds chips of meteorites DaG262 and DaG400 used in the
[Image 3]
David A. Kring.
[Image 4]
Timothy D. Swindle.

From the BBC New Online, 30 November 2000

By BBC News Online science editor Dr David Whitehouse

A new study of Moon meteorites provides fresh evidence that the Earth and
its satellite underwent an intense period of cosmic bombardment just under
four billion years ago.

An analysis of four of the 20 or so known lunar meteorites suggests that the
Moon's surface was melted by a torrent of impacts.

It is estimated that this lunar catastrophe would have lasted only about
200,000 years but, in that time, nearly 2,000 large craters would have been
formed as well as many of the Moon's giant impact basins.

Scientists say that the Earth would have been bombarded to a far greater
extent and that the frequent impacts could have delayed the emergence of
life on the primitive world.



From Exite News, 27 November 2000

Washington State U. prof keeps eye on asteroid

By Jake Smulkowski
Daily Evergreen
Washington State U.

(U-WIRE) PULLMAN, Wash. -- Washington State University associate professor
Scott Hudson is helping to keep the world informed about potentially
hazardous asteroids.

Hudson, an astronomer with the School of Electrical Engineering and Computer
Science, has been monitoring the asteroid Toutatis in its path around the

Toutatis, one of the largest potentially hazardous asteroids at about five
miles across, comes into relatively close quarters with Earth every four

Hudson studies the asteroid with NASA's Goldstone planetary radar in
California and another facility in Puerto Rico. Hudson said the radar
systems are fairly simple.

"It's a lot like the radar at an airport that tracks airplanes," he said.
"It bounces signals off of the object, and we analyze the readings. We can
predict orbits very accurately, and we can predict them for hundreds of
years in the future."

The people of Earth should not prepare for Armageddon just yet, though.

Next time the asteroid passes near Earth, in late November of 2004, it still
will be twice the distance from Earth as the moon.

"This is one of the largest of the Earth-crossing asteroids (asteroids that
cross the Earth's orbit), and it's the one that comes closest to the Earth's
orbit," Hudson said. "Still, we are not worried about this asteroid. We
study a large number of potentially hazardous asteroids. In fact, we study
hundreds of objects."

The asteroid will come close enough that it might be visible by the naked
eye in very dark sky areas, Hudson said.

Toutatis is an unusual asteroid - its orbit is nearly circular.

"Most (asteroids) have fairly elliptical orbits," Hudson said. "They are
often pulled off from the main asteroid belt past Mars by the gravitational
pulls of the planets, especially Jupiter.

"I've been working on radar astronomy for about 15 years. I am mainly
interested in the asteroids that cross the Earth's orbit."

Hudson said the public is interested in Earth-crossing asteroids because of
disaster scenarios.

Perhaps rightly so.

"The amount of energy released in an impact is roughly equivalent to 100,000
megatons of TNT per kilometer of asteroid diameter," he said.

The nuclear bomb dropped at Hiroshima released the equivalent of
one-fiftieth of a megaton.

Hudson is more interested in the positive potential of these asteroids than
doomsday predictions.

"Scientifically, these are very exciting because they are treasure troves of
raw materials," Hudson said. "As we work on the space station and move
towards the colonization of space, they could provide us with many

"I like to think of them in a positive light because of their potential to

(C) 2000 Daily Evergreen via U-WIRE


From Andrew Yee <>


Liquid Mirror Telescope Observations of the 1999 Leonid Meteors
By J. Pawlowski

The November 1999 Leonid Meteor Shower was observed and videotaped using a
Liquid Mirror Telescope (LMT) located at the Johnson Space Center (JSC)
Observatory near Cloudcroft New Mexico. This is the largest aperture optical
instrument ever used for meteor studies. The sensitivity of the LMT along
with its automated meteor detection software enabled detection of Leonid
meteors in the 5 to 12 magnitude range. Leonids of such faint magnitudes
were unable to be seen using our low light level video camera which was
operating concurrently at the same location. Our purpose was to use the data
from both sources to validate the Leonid Mass Distribution Model derived at
JSC by Dr. Mark Matney. This model along with other meteor and orbital
debris models is used for meteoroid and orbital debris risk assessment
performed prior to every Space Shuttle Mission.

A total of 151 Leonids were detected by the LMT over three nights of
observations (November 17, 18, & 19). Their masses were estimated to be
between 10**-4 and 10**-8 grams using meteor analysis software also
developed at JSC. A mass distribution of these lightweight Leonids was
calculated, and the slope of their mass distribution was compared to the
slope of mass distribution of the Leonid Meteor Mass Distribution Model.
There was excellent agreement over the 0.002 to 0.02 milligram range. This
agreement along with the agreement in the 0.02 to 0.2 gram range based on
data from our low light level cameras reported in the April issue of this
publication supports our continued use of the model.


From Michael Paine <>

Dear Benny,

Further to comments from Paul Davies and I about "lifeboats in space", the
idea is also raised in a recent paper published in Planetary and Space
Science. The PDF can be downloaded from (until 1 Dec 2000)

Details and a relevant extract are below.

Michael Paine

Planetary and Space Science
Volume 48, Issue 11, 01-September-2000
Curt Mileikowsky, Francis A. Cucinotta, John W. Wilson, Brett Gladman, Gerda
Horneck, Lennart Lindegren, Jay Melosh, Hans Rickman, Mauri Valtonen, J.Q.
Risks threatening viable transfer of microbes between bodies in our solar
Planetary And Space Science (48)11 (2000) pp. 1107-1115

With relatively long viable flight times in space of about 100,000 years,
the following conclusions can also be drawn:

* Even if life originated only once, either on Earth or on Mars, it
would still have had a very high probability of avoiding catastrophic
extinction by the largest impactors during the heavy bombardment period
by orbiting around its planet (or the Sun) inside ejecta and returning to
its planet tens of thousands of years later once conditions there had again
become habitable. (This life-saving orbiting could be caused by the same
impact that caused the extinction or by earlier impacts.)

* And if longer times of absence from a planet were necessary for
survival, then desendants of microbes that had originated on say
Earth, been transported to Mars and proliferated there, could be
moved back to Earth again and again for periods of up to tens or hundreds
of millions of years, thus preserving the original life.

* In the biological evolutionary literature a lot is written about
extinctions that were possibly caused by impacts.They are always presented
as partial extinctions, for special groups of species, special
environments, etc., never of course as complete extinction of all life on
Earth... with one exception: a very early collision with a Mars-sized
planet, assumed to have created the Moon, would certainly have
extinguished all life on Earth had any been there.

*  The early, very few giant impacts on Earth and Mars which caused
large-scale boiling off of oceans might have extinguished either most
life on the planet except microbes dwelling in rock deep under the surface,
near the temperature wall, or all of life. The first of these
two alternatives may seem more probable, but the second cannot be

* If all early life was extinguished by impact on the Earth or Mars,
it is very improbable that it happened at the same time on both of them.
If it happened on one of them, life could probably have returned from
the other via ejecta carrying viable microbes.

One consequence of this: hypotheses as to whether the origin of life was
relatively easy and frequent or not need not be in influenced by the idea of
early life being often extinguished.


From Scientific American, December 2000

David H. Levy's Shoemaker by Levy: The Man Who Made an Impact
Princeton University Press, Princeton, N.J., 2000 ($24.95).

Their names are memorably linked to Comet Shoemaker-Levy 9, which they
discovered in 1993 and which captured worldwide attention when 21 fragments
of it crashed into Jupiter in July of 1994. Eugene M. Shoemaker, who died in
an automobile accident in 1997, was a geologist who spent much of his career
studying impact craters on the moon and Earth. (He "practically invented the
field of astrogeology," according to Paul W. Chodas of the Jet Propulsion
Laboratory.) Levy is a writer on astronomy and the discoverer of 21 comets.
He skillfully describes Shoemaker's work and sharply delineates his strong
personality. Shoemaker got his lifelong wish to see an impact when that
comet struck Jupiter. And his wish to go to the moon, thwarted by his
health, was fulfilled when the spacecraft Lunar Prospector, carrying one
ounce of his ashes, crashed onto the lunar surface five years to the week
after the last traces of Comet Shoemaker-Levy 9 disappeared.


From Ron Baalke <>

PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011

Contact: Carolina Martinez (818) 354-9382

FOR IMMEDIATE RELEASE                              November 28, 2000


A small hopping robot with froglike abilities that moves by a combination of
rolls and hops to its desired destination may someday hop a ride to an
asteroid and leap its way to other planets in the search for water.

The frogbot, featured as the "robot of the month" in the Robot Watch news
section of Discover magazine's December issue, weighs in at 1.3 kilograms (3
pounds) and is powered by a single motor. It is equipped with a camera,
solar panels, sensors and onboard computer that executes commands
autonomously, making the robot ideally suitable for exploration of distant
planets, comets and asteroids.

Under development jointly by NASA's Jet Propulsion Laboratory and the
California Institute of Technology, both in Pasadena, Calif., the frogbot
can steer and right itself.

"Hopping is a more efficient form of transportation in low-gravity
environments," said Dr. Paolo Fiorini, an engineer in the robotics group at
JPL. "Our hopping robot performs much like a frog, except that it only has
one leg and no tongue. It has a spring between its knees that makes it bend
its legs and hop. When the spring releases, the frogbot takes a 1.8-meter
(6-foot) hop on Earth, which could become a 6- meter (20-foot) leap under
low-gravity conditions on planets like Mars, depending on terrain."

Engineers believe that in low-gravity environments, such as small planets,
and in micro-gravity environments, such as asteroids, wheels successfully
used on rovers may not be the most efficient form of locomotion. In
laboratory experiments, slithering, rolling and hopping have been shown to
be alternative methods of propulsion.

In the future, NASA envisions missions involving dozens of small robotic
vehicles. "To be effective, a small exploratory robot vehicle must
frequently go over obstacles that are many times its body size," said Joel
Burdick, the Caltech co-inventor of the robot. "Hopping or leaping motions
are some of the few effective ways for small vehicles to overcome such
relatively large obstacles."

"Our goal was to come up with a locomotion method and design that would use
a minimal number of instruments and that would be small, compact,
lightweight and still be able to perform useful scientific study," said Dr.
Neville Marzwell, head of the Advanced Projects Office at JPL. Researchers
at Sandia National Laboratories in Albuquerque, N.M., have also developed a
hopping device, with more limited maneuverability.

The frogbot has shown better mobility than rovers on certain terrain. It can
be developed to reach canyon walls and other remote areas, be manufactured
at a lower cost and multiple numbers of the device can be released onto a
planet's surface to cover large distances and communicate with each other.
One frogbot could be lost without hindering the whole network.

The hopping robot technology will be ready in about three to five years and
could help scientists capture images and collect ground samples. One of the
major challenges facing engineers is precision navigation necessary to
control the hopping robot. Engineers are also developing a
hopper that adheres and climbs vertical walls and are testing prototypes on
different ground terrains.

   Pictures are available at

The Advanced Projects Office of Space Flight at NASA Headquarters is the
primary source of funds for this work, which was also sponsored by a
National Science Foundation grant through the Center for Neuromorphic
Systems Engineering at Caltech. Managed for NASA by Caltech, JPL is the lead
U.S. center for robotic exploration of the solar system.


From Andrew Yee <>


Reentry Survivability Analysis of Extreme Ultraviolet Explorer (EUVE)
By R. O'Hara

A reentry analysis of the Extreme Ultraviolet Explorer (EUVE) spacecraft was
performed using the Object Reentry Survival Analysis Tool (ORSAT) - Version
5.0. The analysis was done in response to a request by NASA Headquarters and
Goddard Space Flight Center (GSFC) after a preliminary assessment had shown
that the EUVE reentry may produce a debris area greater than the limit set
within the NASA Safety Standard 1740.14 guidelines.

NASA's 3243 kilogram EUVE spacecraft was launched on June 7, 1992 from Cape
Canaveral Air Station on board a Delta II launch vehicle into a 528
kilometer, 28.5 degree inclined orbit. With the spacecraft nearing its end
of mission and a possible reentry into the Earth's atmosphere expected as
early as October 2001, personnel at Goddard Space Flight Center performed a
reentry analysis using the NASA Johnson Space Center Debris Assessment
Software (DAS) - Version 1.0, in accordance with NASA Policy Directive
8710.3. In the GSFC analysis, there were 18 individual objects predicted to
survive. The total casualty area calculated for these surviving objects was
12.41 m**2, which exceeds the 8 m**2 limit set in the NASA safety standard.
The large debris area implies a potential human casualty risk of
approximately 1 in 5,300. The EUVE spacecraft was not designed with a
propulsion system and therefore cannot perform a controlled reentry. In
order to mitigate the potential risk to human safety from an uncontrolled
reentry of the EUVE spacecraft, a retrieval of the spacecraft using the
Space Shuttle was considered. However, since DAS is a lower fidelity model
and tends to produce a more conservative result, the Orbital Debris Program
Office at JSC was asked to perform a more detailed reentry study using the
higher fidelity NASA-Lockheed Martin ORSAT model to determine if taking such
a measure would be necessary.

Several sophisticated material and thermal properties are included in ORSAT
but do not exist in the DAS code. These enhancements tend to result in fewer
objects surviving reentry when using ORSAT as opposed to DAS for a reentry
analysis. For example, the emissivity is set to 1.0 for all materials
available in DAS, implying blackbody radiation for each component analyzed.
Thus, objects in DAS tend to lose heat faster and are more likely to
survive. In ORSAT, however, the emissivity can be adjusted based upon what
type of material the object is composed of. ORSAT also considers heat of
oxidation during reentry, which means that the object gains heat faster and
will demise more readily. Heat of oxidation is not considered in DAS. ORSAT
also allows for thermal conductivity. With this enhancement and using a
layered approach to modeling the fragments, ORSAT can reduce the overall
debris area by allowing for objects to partially ablate. In contrast to this
method, DAS will allow the entire fragment to survive. And finally, ORSAT
enables the user to supply a wall thickness for an object, making it easier
to model hollow objects. DAS treats all objects as solid and therefore
requires a workaround to approximate the reentry heating to a hollow object.
This workaround has been validated using comparisons with ORSAT runs, though
the more direct approach used by ORSAT is more reliable.

In the ORSAT analysis, only the objects shown to survive with the DAS model
were evaluated, and the high fidelity features of ORSAT were applied to the
reentry analysis. Reentry of the EUVE spacecraft was considered to occur at
an altitude of 122 kilometers with breakup occurring at 78 kilometers. All
of the objects were considered exposed to reentry heating at this breakup
altitude. Objects were also analyzed for possible shielding affects by other
components. Any object shown to demise at the breakup altitude, but was
considered shielded by other spacecraft components, was reanalyzed starting
at the demise altitude for the object shielding it. This allowed for some
conservatism since in reality these objects would have experienced some
heating and possible ablation prior to the demise of the object shielding
it. The final debris area calculated from the more sophisticated ORSAT
analysis of the surviving fragments came to a total of approximately 5.95
m**2, which is well under the 8 m**2 NASA constraint.

The more detailed reentry study of the EUVE spacecraft done using ORSAT has
shown the future uncontrolled reentry of EUVE to be of an acceptably low
risk to human safety and therefore mitigation measures are unnecessary.


From Andrew Yee <>

University of California-Berkeley

Kathleen Maclay, Media Relations
(510) 643-5651

18 Oct 2000

UC Berkeley professors measure exploding world production of new information

Berkeley -- Two University of California, Berkeley, professors have just
finished analyzing all new data produced worldwide last year -- on the
Internet, in scholarly journals, even in junk mail -- and report not just
staggering totals, but a "revolution" in information production and

In their report, "How Much Information?" professors Hal Varian and Peter
Lyman of the UC Berkeley School of Information Management & Systems (SIMS)
report new information production in terms of paper, film, optical and
magnetic data. They analyzed industry and government reports for production
of information that also includes e-mail, digital production, videos, DVDs,
CDs, broadcast outlets, photographs, books and newspapers.

The study has, for the first time, used "terabytes" as a common standard of
measurement to compare the size of information in all media, linking and
interpreting research reports from industry and academia. One terabyte
equals a million megabytes or the text content of a million books. This
standard makes it possible to compare growth trends for different media
using one universal standard.

The numbers in the UC Berkeley report are mindboggling

* The directly accessible "surface" Web consists of about 2.5 billion
documents and is growing at a rate of 7.3 million pages per day.

* Counting the "surface" Web with the "deep" Web of connected
databases, intranet sites and dynamic pages, there are about 550 billion
documents, and 95 percent is publicly accessible.

* Fifty percent of all Internet users are native English speakers,
while English language Web sites account for about 78 percent of all
Web sites, and 96 percent of E-commerce Web sites.

* A white-collar worker receives about 40 e-mail messages daily at the

* Ninety percent of the world's e-mailboxes were found in the United
States in 1984, but that dropped to 59 percent by the end of 1999.
E-mail production accounts for about 500 times as much information as
Web page production each year.

* Worldwide production of books increased by 2 percent in the last

* Production of newspapers in the last year decreased by 2 percent.

* The United States produces 35 percent of all print material, 40
percent of the images and more than half of the digitally stored material.

SIMS professors Lyman and Varian and their research assistants James Dunn,
Aleksey Strygin and Kirsten Swearingen translated original content volume
into bytes, using the terabyte as the project's smallest practical measure.
Then they calculated how much storage each type of media takes when
subjected to different compression techniques, and factored in anticipated

The professors said they were struck by three emerging trends.

One is "the 'democratization of data," the vast amount of unique information
stored and also created by individuals. Original documents created by office
workers represent nearly 90 percent of all original paper documents, while
56 percent of magnetic storage is in single-user desktop computers.

"A century ago, the average person could only create and access a small
amount of information," wrote Varian and Lyman in their report. "Now,
ordinary people not only have access to huge amounts of data, but are also
able to create gigabytes of data themselves and, potentially, publish it to
the world via the Internet."

The second surprise for the professors was the finding that print accounts
for such a miniscule amount of the total information storage. But they said
it doesn't mean print is dead, rather it is a very efficient and
concentrated form for the communication of information.

The third striking finding for them was the dominance of digital information
and its phenomenal growth. This further feeds the democratization of data,
they said, because digital information is potentially accessible anywhere on
the Internet and is a "universal" medium because it can copy from any other

But just because storing vast amounts of information no longer requires an
investment in real estate, the researchers said the ease of production and
access to information may lead people to turn over personal data management
to specialized businesses with giant data storage systems.

"After all," they wrote, "would you rather keep all your family photos on
your PC hard drive, and risk losing everything if it crashes, or on a secure
site managed by Kodak? On the other hand, individuals may prefer to keep
information about themselves in smaller systems that only they control."

The researchers also forecast that businesses will be tremendously affected
by this increase in individuals' instant access to real-time company data,
something that a few years ago was restricted to the upper management.

"The difficulty will be in managing this information effectively making sure
that your suppliers, your employees, and your customers not only have access
to the data they need to make informed decisions, but also can locate,
manipulate and understand it," the report said.

Lyman and Varian caution that our ability to store and communicate
information has far outpaced the ability to search, retrieve and present it.
That's one reason for a place like SIMS, where people can learn the
techniques and technologies for sorting the valuable information from the
superfluous, they said.

"Information management -- at the individual, organizational, and even
societal level -- may turn out to be one of the key challenges we face," the
report said.

"It's the next stage of literacy," Lyman said.

The latest report is not in printed form, because its authors see it as a
"living" document. It can be found at and will be updated
periodically in response to comments from readers.

"It's a good way to kick off a discussion of what information is. We don't
have a very good way of talking about information because it's changing so
fast," said Varian, also co-author of "Information Rules A Strategic Guide
to the Network Economy" (Harvard Business School Press, 1998).

"In the past, we've talked about information in terms of the size of a
physical inventory, such as counting books or films," Lyman said. "But in
the future, the size and format of information will be dynamically reshaped
to the needs of the reader."

EMC Corp., the world's largest data storage systems company, financed the


NOTE: Hal Varian is available at (510) 642-9980 and Peter Lyman at (510)


* "How Much Information?" report
* EMC Corp.

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CCNet ESSAY, 1 December 2000

"In this essay I suggest that, whereas (1) there can be little doubt
that life abounds throughout the universe and is not confined to
Earth, and (2) under special circumstances interplanetary transport of
microbes in impact ejecta may be possible, in view of the evidence to
date the panspermia hypothesis constitutes a philosophical notion rather
than a scientific theory."
   -- Andrew Glikson, 30 November 2000  


By Andrew Glikson <>
Australian National University.
Canberra, ACT 0200

Suggestions of cometary origin and/or transport of microbes and of universal
seeding of life from cometary dust, colloquially known as panspermia (eg.
Hoyle and Wichramasinghe, 1980), constitute an extraordinary claim.
According to Carl Sagan, "Extraordinary claims require extraordinary
evidence". In this essay I suggest that, whereas (1) there can be little
doubt that life abounds throughout the universe and is not confined to
Earth, and (2) under special circumstances interplanetary transport of
microbes in impact ejecta may be possible, in view of the evidence to date
the panspermia hypothesis constitutes a philosophical notion rather than a
scientific theory.  


CCCMENU CCC for 2000