PLEASE NOTE:
*
CCNet 129/2000 - 8 December 2000
--------------------------------
"Some time ago, I reflected wryly that it was about time
that the
universal infection brigade seized on BSE as an illustration of
interstellar infection, and sure enough, up it popped."
-- Jon Richfield, 7 December 2000
"We have no idea whether the origin of life was a gigantic
chemical
fluke, unique in the universe, or an expected result of
inherently
bio-friendly laws. Given this uncertainty on the likelihood of
life
emerging, it is clearly more plausible in the current state of
our
knowledge to conjecture that life may have survived multiple
impacts by a
lifeboat mechanism, or other refuge, rather than re-emerging from
scratch in each window of opportunity."
--
Paul Davies, 7 December 2000
"We're learning all the time that life, in some form or
other, is
incredibly resilient, albeit fluid -- episodically morphing into
new and
better adapted forms rather than succumbing fragilely to the
slightest little stress."
-- Paul Renne, UC Berkeley, 7 December
2000
(1) CATASTROPHE, MOTHER OF EVOLUTION: HOW LIFE SURVIVED EARLY
BOMBARDMENT
Spcae.com, 7 December 2000
(2) CITY CAMPAIGN GATHERS SPACE: SUPPORT FOR ASTEROID EARLY
WARNING SYSTEM
Liverpool Echo, 7 December 2000
(3) THE REALLY, REALLY BIG DIG: IS MINING ASTEROIDS THE FUTURE OF
ISS?
Larry Klaes <lklaes@bbn.com>
(4) BRITAIN'S £30m PROBE WILL BEAT NASA TO MARS
The Daily Telegraph, 7 December 2000
(5) STARDUST AND CARBON IN THE UNIVERSE
ScienceWeek, 1 December 2000
(6) FIRE FROM THE SKY
Bad Astronomer <badastro@badastronomy.com>
(7) SOUNDS OF THE TIMES
Jon Richfield <jonr@iafrica.com>
===============
(1) CATASTROPHE, MOTHER OF EVOLUTION: HOW LIFE SURVIVED EARLY
BOMBARDMENT
From Spcae.com, 7 December 2000
http://www.space.com/searchforlife/life_on_earth_001205_MB.html
By Robert Roy Britt
Mounting evidence from seafloor critters to ancient soil and even
Moon rocks
suggests that life on early Earth survived heavy bombardment from
space
rocks, pointing to an earlier origin for terrestrial life and
opening wider
the window of possibilities for where life might exist in the
cosmos.
The Moon preserves a record of the pummeling it took 4.1 to 3.8
billion
years ago. Earth got nailed by even more space rocks back then,
but the
planet swallowed the evidence by recycling it into the interior
over the
eons.
Early Earth was a lousy place to live. The young solar system was
teeming
with comets and asteroids; many ended their travels by slamming
into our
fledgling planet, destroying entire continents and kicking up
deadly clouds
that circled the globe.
The chaos ended about 3.8 billion years ago. And some scientists
have long
held that only after things quieted down did life get going. But
while
others have argued for years of fossilized evidence that life
existed as far
back as 3.5 billion years ago, efforts to pin down an exact date
for the
origin of life on Earth have so far proved elusive.
In one recent study, scientists found signatures of biological
activity in
rock estimated to be 3.85 billion years old. While not a
discovery of life,
or even fossils, the finding is among the oldest evidence that
life was
around back when things were rough.
"We're learning all the time that life, in some form or
other, is incredibly
resilient, albeit fluid -- episodically morphing into new and
better adapted
forms rather than succumbing fragilely to the slightest little
stress," says
UC Berkeley geologist Paul Renne.
The 3.85 billion-year-old rock, from an island in Greenland, was
dated by
researchers from the Australian National University.
Steve Mojzis, of NASA's Astrobiology Institute, studied the rock
and found
higher-than-normal amounts of carbon-12, a form of carbon that is
used by
microorganisms to construct their own organic building blocks.
Finding a
bunch of it crammed between layers of rock is a strong hint that
life may
have been present.
Meanwhile, a paper in the December 1 issue of the journal Science
reports
strong evidence to support the belief that these microorganisms,
if they
existed 3.85 billion years ago, would in fact have found
themselves on a
planet under attack.
Attack from space
Barbara Cohen of the University of Tennessee analyzed four rock
fragments
that had been blasted off the Moon and found on Earth. Cohen and
her
colleagues found evidence of at least seven separate huge lunar
impacts
between 2.76 and 3.92 billion years ago, bolstering the already
strong
belief in the cataclysmic period known as the Late Heavy
Bombardment.
Previous studies of rocks returned by Apollo astronauts had
already
established the time frame, but those rocks all came from the
near side of
the Moon, near the equator. Cohen analyzed rocks that were
randomly ejected
from the Moon, showing that the bombardment was a total lunar
event.
Cohen and others agree that if the Moon was getting pummeled, so
was Earth.
Because Earth is larger, it would have been hit by at least 10
times as many
space rocks.
"And we're talking large impactors that would make craters
the size of
continents," Cohen told SPACE.com. "During the
cataclysm, 17,000 craters
were created in 200 million years [on Earth]. It would not have
been a great
time to be living on the Earth's surface."
So maybe whatever critters that might have been around weren't on
the
surface. Three possibilities have been put forth: Life warmed its
hypothetical hands on deep-sea hydrothermal vents; it burrowed
deep inside
the Earth; or -- in an exotic twist -- microbes took a hiatus in
space.
Biologists have created a tree of life showing that all living
things can be
traced back to heat-loving organisms, called hyperthermophiles.
Studying
genetic material to create the tree, they say that life either
began in hot
water, or it spent some time there before evolving into slugs,
oak trees,
and rocket scientists.
These "original organisms," clustered around deep-sea
hydrothermal vents,
where Earth belches hot water and minerals into the ocean, might
have
endured for long periods without even noticing the dismal surface
conditions.
But physicist Paul Davies, author of The Fifth Miracle: The
Search for the
Origin and Meaning of Life, dismisses hydrothermal vents as
potential
hideouts. He says the largest impact events would have boiled the
oceans
dry. Seafloor microbes would have been naked to the chaos.
In his book, Davies suggests that huge impacts, known to fling
dust and
rocks into space, might have also carried microbes to safe
refuge. Years
later, after the planet became livable again, a few lucky
microbes might
have returned from the heavens to recolonize. Recent studies have
shown that
microorganisms could in fact survive the brunt of an impact and
the rigors
of space travel.
Still, Davies figures there was an easier way for life to endure
catastrophe.
"The most plausible refuge is the deep subsurface, by which
I mean more than
1 kilometer (0.6 miles) down in the crust, either in the basalt
of the
seabed, or on any land that may have existed during the
bombardment," Davies
told SPACE.com. "Merely being on the sea floor [near a
hydrothermal vent]
would not have provided adequate protection from the largest
impactors,
since these would have created a rock-vapor atmosphere that would
have
boiled the oceans dry."
If any of these scenarios is true, then catastrophe could be
called the
mother of evolution. It remains unknown, however, whether the
events of the
Late Heavy Bombardment forced life to evolve, or if it got wiped
out several
times and had to spring forth over and over.
"We have no idea whether the origin of life was a gigantic
chemical fluke,
unique in the universe, or an expected result of inherently
bio-friendly
laws," Davies says. "Given this uncertainty on the
likelihood of life
emerging, it is clearly more plausible in the current state of
our knowledge
to conjecture that life may have survived multiple impacts by a
lifeboat
mechanism, or other refuge, rather than re-emerging from scratch
in each
window of opportunity."
Maybe it wasn't so bad after all
More new research supports the idea that life could have hidden
out long
enough to hang on during the worst of times. Kevin Zahnle of
NASA's Ames
Research Center, working with Mojzis and Ariel Anbar at NASA's
Astrobiology
Institute, used computer models to study the effect of impacts
during the
Late Heavy Bombardment.
In taking measurements of the 3.85 billion-year-old terrestrial
rock from
Greenland, Ph.D. student Gail Arnold, working with Anbar, did not
find any
signs of iridium in the rock, which should have been present if
there had
been any large impact events around that time. (The element
iridium is
prevalent in comets and asteroids.)
Their work, to be published in an upcoming issue of the Journal
of
Geophysical Research, suggests that impacts large enough to cause
worldwide
disaster were few and far between. And even after the worst
events, life
would only have needed to hang on for about 10,000 years before
Earth rolled
out its bio-welcome mat again, according to the computer models.
"As long as life could hold out in niches during episodic
catastrophic times
(every 30 million years or so), it could have inhabited the
surface during
most of the 'heavy bombardment' era," says Anbar, a
University of Rochester
researcher.
The growing view of life's tenacity means life itself may have
grown, and
still be growing, in more places than scientists previously
thought.
"This greatly extends the number of potential habitats in
the solar system
and beyond," says Davies, the author and physicist.
"For example, life may
still exist deep beneath the surface of Mars. Subsurface life on
Europa is
also possible. Even lunar subsurface life is not totally absurd,
if liquid
water can exist."
Copyright 2000, Space.com
==================
(2) CITY CAMPAIGN GATHERS SPACE: SUPPORT FOR ASTEROID EARLY
WARNING SYSTEM
From Liverpool Echo, 7 December 2000
http://www.liverpool.com/news
POLITICIANS have joined the growing band of support for
Liverpool's bid to
build an early warning system against asteroids threatening
earth.
The funding and building of a super telescope was recommended by
a task
force set up by Science Minister Lord Sainsbury.
It wants a three-metre survey telescope designed to spot much
smaller
objects than those now detected by existing instruments.
Spaceguard UK is lobbying the government to commission John
Moores
University's Telescope Technologies Ltd (TTL) for the project.
Science fiction writer Sir Arthur C Clarke, creator of 2001: A
Space
Odyssey, has already pledged his support in an open letter to the
people of
Liverpool.
Dr Benny Peiser, a researcher for JMU and spokesman for
Spaceguard UK, said
he has now received a letter from 11 North West MPs , MEPs Den
Dover and
Brian Simpson, Lord Alton of Liverpool and Lord Wade of Chorlton,
pledging
their full support for the campaign.
He said: "The broad and enthusiastic response by politicians
from all
parties and regions in the North-West shows that there is not
only
widespread support, but real expectation that the recommended
spaceguard
telescope will be built on Merseyside.
"Clearly this is a golden opportunity for TTL and Merseyside
to become one
of the world's top producers of high-technology telescopes and
their
associated equipment."
TTL is a subsidiary of JMU and is the only company in the UK
designing and
producing professional astronomical telescopes.
The Department of Trade and Industry is expected to make an
announcement
early next year.
see also: JMU TO SAVE THE WORLD?
http://cwis.livjm.ac.uk/jmunews/templates/template1.asp?ref=200012061100000549236500000000
===============
(3) THE REALLY, REALLY BIG DIG: MINING ASTEROIDS THE FUTURE OF
ISS?
From Larry Klaes <lklaes@bbn.com>
http://www.feedmag.com/essay/es425_master.html
Harvesting asteroids -- for everything from platinum to oxygen to
water --
has long been the stuff of science fiction. Joël Glenn Brenner
investigates
the efforts to make it a profitable fact.
WHEN THE FIRST OCCUPANTS boarded the International Space Station
on November
2, there was none of the excitement or awe that marked the heady
days of
Gemini or Apollo. The station is being touted as man's first step
toward a
continual presence in space, but who cares? Didn't the Russians
already
accomplish this with the Mir? And what's the point of putting
more humans in
earth-orbit, especially when it's accompanied by a price tag of
more than
sixty billion dollars?
While NASA hails the prospect of scientific breakthroughs flowing
from ISS,
researchers are skeptical. Few believe that the station's
scientific value
will ever justify its astounding cost -- much of which is due to
the need to
haul into orbit every gram of material used to build the station
and keep it
running.
The station will weigh some 900,000 pounds when it is finally
completed in
2006, resulting in launch costs alone of about ten billion
dollars, and that
doesn't even account for astronauts, food, fuel, supplies or
additional
research equipment.
But suppose we didn't have to carry everything up there? What if
we used the
station to learn how to process resources from space itself? It
may sound
far-fetched, but this could be the most profound and significant
payoff to
result from ISS, allowing us to build future stations, research
facilities,
factories and living quarters at a fraction of the cost of space
enterprises
today.
FULL STORY at http://www.feedmag.com/essay/es425_master.html
===============
(4) BRITAIN'S £30m PROBE WILL BEAT NASA TO MARS
From The Daily Telegraph, 7 December 2000
http://www.telegraph.co.uk/et?ac=000579381554028&rtmo=VD8kg6wK&atmo=99999999&pg=/et/00/12/7/nbeag07.html
By David Derbyshire, Science Correspondent
BRITAIN is on course to send a spacecraft to Mars in 2003 to
search for
alien life, beating a rival Nasa mission by weeks.
The team behind Beagle 2, the most ambitious British space
mission in
history, say the probe should bounce on to the surface of the Red
Planet on
Boxing Day, 2003. Prof Colin Pillinger, the Open University
academic
researcher leading the project, said yesterday that he had
backers to
underwrite the £30 million cost.
Beagle 2, named after Charles Darwin's ship, will be stowed on
the European
Space Agency's Mars Express spacecraft, which is due to be
launched from
Baikanour, Kazakhstan, in June 2003. The 130lb craft is really a
small,
stationary laboratory, designed to detect organic matter, water,
minerals
and evidence of long-extinct alien bacteria.
FULL STORY at
http://www.telegraph.co.uk/et?ac=000579381554028&rtmo=VD8kg6wK&atmo=99999999&pg=/et/00/12/7/nbeag07.html
================
(5) STARDUST AND CARBON IN THE UNIVERSE
From ScienceWeek, 1 December 2000
http://scienceweek.com/current.txt
ASTROPHYSICS: ON STARDUST
In astrophysics, the term "dust" refers to various
entities: a)
interplanetary and cometary dust are found in the Solar System;
b)
circumstellar dust is found around stars; c) interstellar dust
is found between stars. Individual dust particles are usually
called "dust
grains" and range in size from approximately 10 nanometers
up to the micron
range (with an average size about the
size of particles in cigarette smoke). Interstellar dust
extinguishes and
reddens starlight, can be detected by its absorption and emission
of
infrared radiation, and can be detected by its polarizing effect
on
starlight. The exact composition of interstellar dust is
uncertain, but
infrared absorption measurements indicate that a significant
fraction of the
material is organic. In general, interstellar dust is believed to
be carbon,
iron, and silicates mixed with or coated
with frozen water.
* J. Mayo Greenberg (University of Leiden, NL) presents a review
of recent
research on interstellar dust and cometary dust, the author
making the
following points:
1) The extinction curve for interstellar dust, which indicates
the reduction
of light intensity at each wavelength, indicates there must be 3
types of
dust grains:
a) The particles that block light in the visible spectrum are
elongated
grains nearly 0.2 microns in diameter and approximately 0.4
microns in
length. These particles account for approximately 80 percent of
interstellar
dust, with each grain containing a rocky core surrounded by a
mantle of
organic materials and ice.
b) A hump in the ultraviolet part of the extinction curve
suggests the
presence of smaller particles of approximately 5 nanometers
diameter, which
comprise approximately 10 percent of the total dust mass. These
grains are
most likely amorphous carbonaceous solids that probably contain
some
hydrogen but little or no nitrogen or oxygen. c) Finally, an even
smaller
type of particle, approximately 2 nanometers in diameter, is
apparently
responsible for blocking light in the far ultraviolet region.
These smallest
particles, which constitute the remaining 10 percent of the dust
mass, are
believed to be large molecules similar to the polycyclic aromatic
hydrocarbons emitted in automobile exhaust.
2) The author postulates a
100-million-year "dust cycle", which dust
grains undergo approximately 50 times before their destruction:
a) In diffuse dust clouds, where gas is sparse, the dust is a
mixture of
core-mantle grains, carbonaceous particles, and polycyclic
aromatic
hydrocarbon-like (PAH-like) molecules.
b) When the dust enters a dense gas cloud, atoms and molecules of
gas adhere
to the core-mantle grains and form an outer mantle of ice. The
carbonaceous
particles and PAH-like
molecules also accrete on the core-mantle grains.
c) Ultraviolet radiation affects the material in the ice mantle,
creating a
layer of complex organic compounds of yellowish color.
d) As the cloud of dust and gas contracts to form a star, some of
the
core-mantle dust grains clump together and become comet nuclei.
But the vast
majority of the dust is dispersed.
e) Returning to a diffuse cloud, the core-mantle grain is exposed
to harsher
radiation that evaporates the ice mantle and further processes
the organic
material. The complex of organic compounds turns from yellowish
to brown.
f) Supernova shock fronts accelerate the dust grains, causing
violent
collisions that shatter the organic mantles. The debris becomes
the
carbonaceous particles and PAH-like molecules.
3) The author points out that as astronomers make new discoveries
about the
chemical composition of both comets and interstellar dust, they
are becoming
convinced that comets originally formed as clumps of dust grains.
In
addition, comet dust may have played a role in seeding life on
Earth. Each
loose cluster of comet dust not only contains organic materials,
but also
has a structure that is ideal for chemical evolution once it is
immersed in
water. Experiments have indicated that small molecules could
easily
penetrate such clumps from the outside, while large molecules
would remain
sequestered in the interior. The author states: "Such a
structure could
stimulate the production of ever larger and more complex
molecules, possibly
serving as a tiny incubator for the first primitive life forms. A
single
comet could have deposited up to 10^(25) of these 'seeds' on the
young
Earth."
-----------
J. Mayo Greenberg: The secrets of stardust. (Scientific American
December
2000)
QY: J. Mayo Greenberg, University of Leiden, NL
-------------------
Summary by SCIENCE-WEEK http://scienceweek.com
1Dec00
For more information: http://scienceweek.com/swfr.htm
-------------------
Related Background:
ON CARBON IN THE UNIVERSE
Carbon is a major factor in the evolutionary scheme of the
Universe because
of its abundance and its ability to form complex chemical
entities. It is
apparently also a key element in the evolution of prebiotic
molecules. The
different forms of cosmic carbon range from carbon atoms and
carbon-bearing
molecules to complex solid-state carbonaceous structures, and
evidence
gathered during the past decade has considerably enhanced our
understanding
of the physical and chemical properties of carbon materials in
space. *Th.
Henning and F. Salama (2 installations, DE US) present a detailed
review of
the subject, the authors making the following points:
1) More than 75 percent of the 118 *interstellar and
circumstellar molecules
identified to date are carbon-bearing molecules, and one
component of
interstellar dust is evidently carbonaceous. The cosmic evolution
of carbon
from the interstellar medium into *protoplanetary disks and
*planetesimals,
and finally into habitable bodies, is intrinsic to the study of
the origin
of life.
2) Carbon plays an important role in the physical evolution of
the
interstellar medium because it is the main supplier of free
electrons in
diffuse interstellar clouds, thus contributing to the heating of
interstellar gas.
3) The observation of unidentified ubiquitous molecular and
solid-state
features in astronomical spectra, and the realization that these
features
are linked to carbonaceous materials, have resulted in major
scientific
progress in the past decade. Laboratory and theoretical studies
stimulated
by these astronomical observations have led to a better
understanding of the
various forms of cosmic carbon such as polycyclic aromatic
hydrocarbons,
carbon-chain molecules, carbon custers, and carbonaceous solids.
These
investigations have also led to the detection of novel forms of
carbon and
laid the foundations for the chemistry of *fullerenes.
4) The authors present the following categorization of carbon in
space:
a) Carbon-rich circumstellar envelopes around *red giant and
*asymptotic
giant branch (AGB) stars: CO, C(sub2)H(sub2), complex
hydrocarbons,
gas-phase polycyclic aromatic hydrocarbons.
b) Diffuse interstellar medium: C+, simple diatomic molecules,
gas-phase
polycyclic aromatic hydrocarbons and carbon chains.
c) Dense interstellar medium: CO, complex hydrocarbons.
d) Interstellar material in primitive meteorites: polycyclic
aromatic
hydrocarbons.
5) The authors suggest that the widespread distribution of
complex organics
in the interstellar medium has profound implications for our
understanding
of
a) the chemical complexity of the interstellar medium,
b) the evolution of prebiotic molecules,
c) the impact of this evolution on the origin and evolution of
life on early
Earth through the exogenous delivery (by cometary encounters and
meteoritic
bombardments) of prebiotic organics.
-----------
Th. Henning and F. Salama: Carbon in the Universe. (Science 18
Dec 98
282:2204)
QY: Th. Henning, Astrophysikalisches Institut und
Universitats-Sternwarte,
Schillergabchen 2-3, D-07745, Jena DE.
-----------
Text Notes:
*interstellar and circumstellar molecules: In this context, an
interstellar
molecule is any molecule that occurs naturally in clouds of gas
and dust in
space. In general, a circumstellar molecule is any molecule that
occurs in gas and
dust surrounding a star.
*protoplanetary disks: These are dust disks surrounding young
stars; it is
from these disks that planets presumably form.
*planetesimals: Planetesimals are bodies with dimensions of
10^(-3) to
10^(3) meters that are believed to form planets by a process of
accretion.
The term "accretion" refers to an
aggregation, an increase in the mass of a body by the addition of
smaller
bodies that collide and adhere to it, provided the relative
velocities are
low enough for coalescence. As the mass
of the agglomerate increases, so does the rate of accretion, and
this
accretion process is believed to generally occur in the form of a
disk. A
stellar accretion disk is a swarm of dust grains that evolve into
planetesimals and then planets.
*fullerenes: Fullerenes are large molecules composed entirely of
carbon,
with the chemical formula C(sub n), where n is any even number
from 32 to
over 100. They apparently have the structure of a hollow
spheroidal cage
with a surface network of carbon atoms connected in hexagonal and
pentagonal
rings.
*red giant: A red giant star is a star in a late stage of
evolution. Having
exhausted the hydrogen fuel in its core, the star is burning
elements heavier than hydrogen. It has
a surface temperature of less than 4700 degrees Kelvin and a
diameter 10 to
100 times that of the Sun.
*asymptotic giant branch (AGB) stars: These are stars that occupy
a strip in
the *Hertzsprung-Russell diagram that is almost parallel to and
just above
what is called the "giant branch" off the
*Main Sequence. Stars evolve from the horizontal H-R branch to
the
asymptotic giant branch when they have exhausted the helium in
their cores
and are instead burning helium in a shell.
*Hertzsprung-Russell diagram: The Hertzsprung-Russell diagram is
a plot of
stellar absolute magnitude against spectral type, and is perhaps
the most
useful diagrammatic aid in astrophysics. It allows the portrayal
of the
evolution of a star as occurring along various paths in the
diagram.
*Main Sequence: The Main Sequence is a region on the
Hertzsprung-Russell
diagram where most stars lie, including our own Sun. The
evolution of a star
can be diagrammed as a movement along the Main Sequence and an
eventual
branching off the Main Sequence to regions associated with
various types of
old stars.
-------------------
Summary & Notes by SCIENCE-WEEK http://scienceweek.com 26Feb99
For more information: http://scienceweek.com/swfr.htm
Copyright 2000, Science Week
============================
* LETTERS TO THE MODERATOR *
============================
(6) FIRE FROM THE SKY
From the Bad Astronomer <badastro@badastronomy.com>
Benny--
The article about a New Hampshire fire possibly sparked by a
meteorite in
the December 6 CCNet caught my attention. As most of your readers
undoubtedly know, meteorites (at least, ones under a hundred
meters in
diameter!) are generally cool when they hit, and will not spark a
fire. The
story had enough merit, however, for me to follow it up. I talked
to
Stephanie Hanes, the Concord Monitor staff reporter who wrote the
original
story, as well as Sandt Michener, who works at the Christa
McAuliffe
Planetarium in Concord. They directed me to some of the
witnesses.
Dick Szopa, a local resident of Salisbury, New Hampshire, was
probably the
first person to see it. I talked with him about what he saw. Some
of his
description was consistent with a meteor, but some was decidedly
not. The
object was falling from the sky when he first saw it, but
he stated several
times that it "arched" across, and went so far as to
compare it to a
basketball thrown at a hoop. That alone would indicate it was not
a meteor,
which would have been falling straight in.
There were two fires, separated by a couple of meters. There is
no
indication of any remaining object that might have started the
fires. If it
had been a meteor, it would either have had to split into two
pieces or
bounce, both of which strike me as highly unlikely given the lack
of a
"remnant".
The owner of the property on which the object hit is David Ayoub.
He said a
pass with a metal detector gave a positive reading the night of
the impact,
but the next day around noon there was no reading at the same
spot. He
admitted he had not used the detector for some time, but did test
it on some
coins and it worked properly (even identifying which coin was
which). There
were a lot of people there (media and the like) between the two
times he
used the detector, so it's possible that someone found an object
and took
it.
Szopa said that there was no noise despite his being only 200
yards away,
and it was moving quickly. Yet there is no crater, and the only
holes in the
ground look to be from burrowing animals, according to people
that were at
the scene.
All the accounts are more consistent with something that was
thrown from a
short distance away. Several of the witnesses said it looked like
a firework
of some kind, but it was falling quickly with no sound. The
location is
fairly rural, with a few houses on 3 acre lots abutting a large
deep forest.
It's possible that some people were in the woods and launched
some sort of
fireball (a Roman candle or some such thing). That would explain
the arcing
trajectory, two fires with no remnant and the lack of noise and
crater.
Eyewitnesses also describe it as being red, more consistent with
fireworks
than a meteor.
There are some unconfirmed accounts of witnesses 40 miles away
spotting
something in the sky at about the same time, but I have not
substantiated
these yet. I will not dismiss them out of hand, but it seems this
is more
likely coincidence given the other accounts.
In my opinion, this is still worth following up, but most likely
will end up
being something more mundane than a meteorite.
Followup articles can be found at
http://www.concordmonitor.com/stories/front0400/salisbury_fireball.shtml
(which mentions CCNet and a few familiar names!) as well as
http://www.msnbc.com/local/mul/m2678.asp
-Phil Plait
=================
(7) SOUNDS OF THE TIMES
From Jon Richfield <jonr@iafrica.com>
Professor Chandra Wickramasinghe and Professor Sir Fred Hoyle are
quoted as
having written to the Times in terms that resurrect suspicions
that they are
indulging in satirical japes. They exploit a dilemma that leaves
them
winners either way: whether their parody of panspermic hypotheses
is
intended seriously or satirically, we find ourselves compelled to
respond
willy-nilly. We cannot let either a challenge or a tease pass,
because either would be an equal
betrayal of other readers. Some time ago, I reflected wryly that
it was
about time that the universal infection brigade seized on BSE as
an
illustration of interstellar infection, and sure enough, up it
popped. It is
a weary theme. Consider a few items from their Times letter.
"Diseases of plants and animals have a long history of
mysterious
appearances without any satisfactory explanation being offered of
where they have come from."
A quantitative argument presented as usual as a real knock-down,
together
with a few qualitative question beggings. How much explanation is
needed to
satisfy the auditors? Suppose that a new strain of microbe
undergoes a minor
series of mutations, whether by corruption or by deletion or
duplication of
genetic material, and this produced a new strain of epidemic
infection; How
rare was the ancestor? Was it known to microbiology? Does it get
discovered
at all? (Some germs never do, you know!) Suppose it does not get
discovered
soon. We isolate and identify the mutant strain. We speculate on
its origin.
We say: "Well, we don't know you, but you might have derived
from such and
such a microbe, which possibly we also do not know."
How satisfactory is that? Not perfectly, surely. But for most
biologists it
would do for most practical purposes.
Cosmologists are less easily satisfied. They demand that instead
of wild
guesses at mutations, we make the simpler assumption instead that
the new
microbe must have come from space. Two centuries ago if we were
assured that
the new disease came from space, we would have said:
"Jeepers and Odzooks!
What they won't discover next!" and only Thomas Jefferson
would have dissented. One
century ago and we would have said: "Pull the other one; we
know all about
space and microbes and that idea is nonsense." In the
last decade or three
we should be saying: "Come off it china! It doesn't seem
impossible in
principle, but really! There is a lot of nonsense that is not
technically
impossible."
If everything for which we can detail no "satisfactory"
explanation must
come from space, it is a constipated, sterile, constrained world
we inhabit
in the midst of a bounteous, teleological and whimsical universe.
"Life on Earth is far too intricate to have evolved here in
isolation from the rest of the Universe."
Once again an absolute assertion of a quantitative proposition.
As for its
merits, I have demonstrated in another essay, without any
sociological
appeals, that not only is there no support for the denial of
Earth's
capacity to produce life, but if we assume instead that all life
or living
novelties stem from exotic sources, we wind up with ludicrous
conclusions
for both the nature of and continuing prospects for our life, its
evolution
and ecology.
All this without invoking any spontaneous common-sense allergies
to the
ideas of alien life, or anal-retentive appeals to Occam.
"Recent studies have shown that much of the material
escaping from
comets is in the form of organic particles that cannot be
distinguished from biomaterial. The input to the Earth is
estimated to
be several tens of tonnes of cometary material per day,
sufficient, if it
was all in the form of bacteria, to give a daily incidence of
several
hundred thousand bacteria per square metre of area."
This is surely a joke? "Cannot be distinguished from
biomaterial" sounds so
ingenuous that one blushes to ask what the accessible diagnostic
criteria
might be. To read the phrase, one would swear that Buck Rogers
and Flash
Gordon had retrieved and tested a few kilos of the material on a
routine
space walk! And yet, it seems we are speaking mainly of
spectroscopic
evidence and a few collisions of microscopic particles with
collecting plates. On
earth we (H&C included) would not accept anything so tenuous
as evidence for the vicar
having farted in church, but in space we proceed directly to go,
without
stopping in Jail, and collecting on the way: "sufficient, if
it was all in
the form of bacteria..."
IF it really is a major proportion, IF it is biological, IF it is
living, IF
it is microbial...
But there is better to come: "For the most part the material
simply washes
away." What on earth does this mean? Washes away from what?
Washes off the
Earth and back into space? Washes off the backs of polluted
cattle? I assume
that the Hoyle and Wickramasinghe mean that the invader germs
land on places
where they get rained off or something.
"But, in rare cases, a connection may occur and if this
escalates a
new disease can be born."
More woolliness. More handwaving or what "rare" means.
Once every many cows?
Once every many years?
"Small particles of bacterial and viral sizes descend
through the
Earth's stratosphere mostly during the winter months, and we
believe that
the nearly unique English and Welsh practice of out-wintering
cattle
explains why BSE hit English and Welsh farms more severely than
elsewhere. English and Welsh farmers move cattle frequently from
field to
field, maximising their chance of picking up any pathogen that
may fall
during the winter months from the air onto the grass."
I wonder where they get that idea from. Are we speaking only
about northern
hemisphere winters? What about summer rainfall regions?
Where I grew up in
a warm temperate area far larger than England, and smaller than
other
similar climatic areas in the southern hemisphere, cattle are
commonly out
during the winter months.
Without subjecting Chandra Wickramasinghe and Fred Hoyle's letter
to The
Times to more detailed painful analysis, I am afraid that their
remarks on
agricultural matters are not only parochial, but largely
nonsensical, even
more so than their biological views in general.
Jon Richfield
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*
CCNet CLIMATE CHANGE & CLIMATE SCARES, 8 December 2000
------------------------------------------------------
"Since the collapse of the Hague conference, media
organisations
which were previously swept along by the warming hype have now
begun to
look more critically at the issue, including `Aunty' herself -
the
BBC."
-- John L. Daily, 1 December 2000
"For the climate sceptics who doubt that human release of
greenhouse
gases is the main cause of global warming, one of the more
plausible
alternatives is that changes in the Sun might be responsible.
Researchers in Denmark now show how and where a link between
global
cloudiness and solar activity could affect climate in unforeseen
ways."
-- Philip Ball, Nature, 6
December 2000
"If large changes in atmospheric CO2 in the past have not
produced
the climate response we thought they had, that undermines the
case
for reducing fossil fuel emissions."
-- Lee Kump, Pennsylvania State
University, 6 December 2000
(1) WHILE EFFORTS TO RESCUE GLOBAL WARMING DEAL FAIL...
From the BBC News Online, 8 December 2000
http://news.bbc.co.uk/hi/english/world/americas/newsid_1060000/1060483.stm
Senior officials from the United States, the European Union and
other key
countries have failed in their attempt to salvage something from
the
abortive climate change summit in November in The Hague.
The ministers have returned home after a hastily arranged two
days of talks
in the Canadian capital, Ottawa, in which they had hoped to find
enough
common ground to reach a deal on cutting greenhouse gas
emissions.
Canadian Environment Minister David Anderson said: "It would
have been nice
to get the officials to hammer out an agreement, but that has not
happened.
That's the bad news,"
FULL STORY at
http://news.bbc.co.uk/hi/english/world/americas/newsid_1060000/1060483.stm
====================
(2) ... ANOTHER CLIMATE SCARE BITES THE DUST: CO2 MAY NOT BE
DRIVING GLOBAL
WARMING AFTER ALL
From the University of Ottawa, 6 December 2000
http://www.uottawa.ca/services/markcom/public_html/english/news/001206_1-e.html
More than hot air: Geologist offers a new view of greenhouse
gases
OTTAWA, Wednesday, December 6, 2000 - Global warming is a lot
more
complicated than is generally assumed, and we may have to rethink
how we
deal with the issue.
University of Ottawa and Ruhr University (Germany) geologist Jan
Veizer and
his colleagues from Belgium have assembled a very different
picture of the
physical and chemical conditions that have contributed to the
past warming
or cooling of our planet. An increase in the atmospheric volume
of
"greenhouse" gases such as carbon dioxide - which has
been blamed as the
primary cause of recent increases in the world's average annual
temperature
- is just part of the story.
In an article being published this week in the definitive
scientific journal
Nature, Veizer and colleagues conclude that past climates and
estimates of
carbon dioxide concentrations disagree. An increase in the level
of
greenhouse gases may be a natural side effect of climate change.
Our own
industrial contribution may enhance a given natural trend but not
reverse
it. The release and consumption of carbon dioxide goes hand in
hand with
other greenhouse gases. In order to mitigate our impact on this
balance, we
should take into account the cumulative role of all greenhouse
gases,
particularly of water vapour as the leading agent that modulates
our
climate.
COLD COMFORD FOR OUR ENVIRONMENTAL AGENDA
Jan Veizer knows it is not politically correct to suggest that
carbon
dioxide is not the primary culprit in global warming. But he does
argue that
it is scientifically correct to say so, and he has 20 years'
worth of
acclaimed research to support that opinion.
"It needs a bit of perspective, that's all," he says.
His perspective covers the last 550 million years of the earth's
history.
That's how far back he and his colleagues have been able to
measure the
amounts of chemicals found in marine shells from around the
world. These
reveal major changes that took place in the amount of oxygen
isotopes in
seawater, a key indication of changes in temperature associated
with major
climatic events such as ice ages.
It was thought that those events were restricted to certain parts
of the
globe, but the work of Veizer and his colleagues has revealed
that tropical
areas cooled down at the same time. Since warming and cooling
trends have
usually been credited to changes in the levels of the notorious
"greenhouse"
gas, carbon dioxide, and the results disagreed, the observations
challenged
the existing model. In particular, Veizer wondered where the
atmosphere's
excess CO2 went so that the world could cool down.
Trees and soils are often seen as the most important
"sinks", where CO2 and
water are absorbed from the air and soil. That is why much of the
environmental debate that took place in The Hague last month
focused on the
world's forests. If we are responsible for warming up the planet
by pumping
more carbon into the air by burning fossil fuels in our
automobiles and
elsewhere, then a sufficient amount of forest cover should be
able to remove
this carbon from the atmosphere.
Yet Veizer suggests that the situation is much more complex.
Based on work
with his former student K. Telmer, presently at the University of
Victoria,
he argues that there is a crucial link between the way carbon and
water each
cycle through plants, the atmosphere and the ground. In order to
fix one
molecule of carbon, a plant has to transpire almost one thousand
molecules
of water. Yet, the air and soils contain less than one hundred
molecules of
water to each molecule of carbon dioxide. The system is therefore
water, not
CO2, limited. With warmer climate, and greater humidity, forests
may play an
enhanced role in the CO2 budget of the atmosphere.
That may be cold comfort to our environmental agenda, which
should be more
inclusive and consider all greenhouse gases, not just CO2. In
particular, it
should take into account the modulating role of the most
important
greenhouse gas, water vapour.
Veizer is sympathetic to arguments that we should reduce
pollution. He
simply does not want those arguments to be premised on incomplete
science.
And on that basis he suggests that we should in fact continue
with plans to
lower CO2 emissions, even if it is for entirely different
reasons.
"In the end, I am all for it, because it is in fact
pollution and we only
have one planet to live on," he says.
For more information:
Bob LeDrew, Communications Officer
University of Ottawa
Tel.: (613) 562-5800, ext. 3154
E-Mail: rledrew@uottawa.ca
=============
(3) FOSSILS NAG AT CARBON'S CLIMATE ROLE
From the BBC News Online, 7 December 2000
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1060000/1060125.stm
Researchers who have examined the fossil record say it questions
the role of
carbon dioxide (CO2) as the main force driving climate
variability.
FULL STORY at
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1060000/1060125.stm
==============
(4) CO2 AND GLOBAL CHANGE
From th Greening Earth Society
http://www.greeningearthsociety.org/Articles/2000/change.htm
By Robert C. Balling Jr., Greening Earth Society Science Advisor
Who doubts that during the last century that there have been
significant
changes in earth's climate? Such a statement is true no matter
which century
you cite in our planet's recorded history. This is the central
problem for
researchers who claim to have "fingerprinted" human
impact on climate in
this one.
While the near-surface thermometer record seems to show warming,
satellite-based and balloon-based measurements of temperature in
the lower
atmosphere do not. It is in the nature of scientific
investigation that
there will be scientific debate surrounding these differential
trends for
years to come. But little debate surrounds one significant change
in climate
observed across land areas all around the world: the diurnal
temperature
range is declining.
"Diurnal temperature range" is the spread between high
and low temperature
on a day-to-day basis. When we say, "diurnal temperature
range is declining"
what we are saying is, morning temperatures are rising and
afternoon
temperatures either are declining or remain unchanged. As a
consequence, the
difference between the two (maximum-minimum temperature) is
declining. This
pattern shows up in most land areas across the planet.
This strong and nearly universal signal receives enormous
attention in the
climatological community because it may be related to the buildup
of
greenhouse gases and/or highly interrelated increases in
cloudiness,
atmospheric water vapor, atmospheric turbulence, or soil
moisture.
Variations in diurnal temperature range even have been related to
phases of
the moon!
In a recent article in Geophysical Research Letters, yet another
mechanism
surfaces as a way of accounting for the observed decrease in the
diurnal
temperature range. Collatz et al. note that an increase in
vegetation would
produce a series of feedbacks involving water vapor, soil
moisture, and
turbulence that could decrease diurnal temperature range. As an
illustration
of what they are getting at, imagine the difference between daily
maximum
and minimum temperatures in a forest and an adjacent parking lot.
Collatz et al. used a numerical model of climate that includes a
detailed
vegetation scheme. They conclude that the observed decline in
diurnal
temperature range could be related to "reported increases in
vegetation
cover in the Northern Hemisphere." Identification of the few
areas where
diurnal temperature range is increasing as regions where land
degradation,
deforestation, and/or desertification are underway adds support
to their
argument.
It is also in the nature of science that one might debate the
cause of the
declining diurnal temperature range for years to come. But it is
more than a
little interesting to the Greening Earth Society that an increase
in
vegetation cover in the Northern Hemisphere emerges from this
research as a
significant contributor to this widely-observed climate signal.
We will add
that a decline in diurnal temperature range itself yields
tremendous
benefits to plant life. If it's not as hot in the afternoon, the
stress of
afternoon heat on plants is reduced. Higher morning temperatures
would
reduce the stress associated with frost or sub-freezing
temperatures.
In discussions of global climate change, there often is reference
to
"feedback loops." This research points to one not often
considered.
Reference
Collatz, G.J., Bounoua, L., Los, S.O., Randall, D.A., Fung, I.Y.,
and
Sellers, P.J. 2000. A mechanism for the influence of vegetation
on the
response of the diurnal temperature range to changing climate.
Geophysical
Research Letters, 27:3381-3384.
=============
(5) SOLAR BLOW TO LOW CLOUD COULD BE WARMING PLANET
From Andrew Yee <ayee@nova.astro.utoronto.ca>
From Nature News Service, 6 December 2000
[ http://helix.nature.com/nsu/001207/001207-6.html
]
Wednesday, 6 December 2000
Solar blow to low cloud could be warming planet
By PHILIP BALL
For the climate sceptics who doubt that human release of
greenhouse gases is
the main cause of global warming, one of the more plausible
alternatives is
that changes in the Sun might be responsible. Researchers in
Denmark now
show how and where a link between global cloudiness and solar
activity could
affect climate in unforeseen ways [1].
Henrik Svensmark and Nigel Marsh of the Danish Space Research
Institute in
Copenhagen have focused on cosmic rays. These are
very-high-energy rays that
are similar to X-rays, but are packed with even more energy. In
the latest
issue of Physical Review Letters, Svensmark and Marsh reveal
evidence that a
decrease in solar activity allows more cosmic rays to enter the
Earth's
atmosphere, and that this in turn affects cloud formation.
The idea that cosmic rays can influence cloud formation was put
forward by
Svensmark in 1997 [2,3], when he showed that there was a
correlation between
total cloud cover over the Earth and the influx of cosmic rays
produced by
catastrophes in our Galaxy. The rays are thought to collide with
particles
or molecules in the atmosphere, leaving them electrically
charged, or
'ionized'.
These ionized particles then seed the growth of cloud water
droplets.
The heat output of the Sun rises and falls roughly every 11
years. This
'solar cycle' is usually traced out by the recurrent appearance
of sunspots,
although the change in the Sun's heat output is tiny -- about
0.1%. This is
too small to have a direct effect on climate. But various
indirect
influences are possible, and the cosmic rays fall into this
category.
The Sun helps to protect the Earth from cosmic rays. It
constantly releases
charged subatomic particles. These stream through the Solar
System as the
solar wind, carrying with them an imprint of the Sun's magnetic
field. It is
these 'field rays' that interact with, and partially shield the
Earth from,
cosmic rays.
The strength of the solar wind depends on the level of solar
activity, and
so varies with the sunspot cycle. When the solar wind blows less
forcefully,
more cosmic rays streak through our atmosphere.
Clouds have a strong yet subtle effect on climate. Clouds that
form low in
the sky are relatively warm and made up of tiny water droplets.
These tend
to cool the planet by reflecting sunlight back into space. High
clouds are
colder, consisting mostly of ice particles, and they can have the
opposite
effect of warming the Earth by trapping heat.
By studying satellite measurements of different cloud types since
1980,
Svensmark and Marsh have found that only low-altitude clouds
(less than 3.2
kilometres above the Earth) seem to vary in step with the rise
and fall of
the cosmic-ray flux. Clouds higher than these appear insensitive
to changes
in the flux. "It is imperative to understand which cloud
types are
influenced by galactic cosmic rays," the researchers say.
They argue that the imprint of the solar magnetic field in the
solar wind
has increased over the past century. So the shielding from cosmic
rays will
have increased, decreasing the formation and cooling influence of
low clouds
and providing a possible contribution to the observed global
warming of the
past 100 years.
[1] Marsh, N. D. & Svensmark, H. Low cloud properties
influenced by cosmic
rays. Physical Review Letters 85, 5004-5007 (2000).
[2] Svensmark, H. & Friis-Christensen, E. Journal of
Atmospheric
Solar-Terrestrial Physics 59, 1225 (1997).
[3] Svensmark, H. Influence of cosmic rays on Earth's climate.
Physical
Review Letters 81, 5027-5030 (1998).
© Macmillan Magazines Ltd 2000 - NATURE NEWS SERVICE
=============
(6) SOLAR FORCING OF CLIMATE: A MEANS OF AMPLIFICATION?
From C)2 Science, 6 December 2000
http://www.co2science.org/journal/2000/v3n34c1.htm
Reference
Tobias, S.M. and Weiss, N.O. 2000. Resonant interactions between
solar
activity and climate. Journal of Climate 13: 3745-3759.
Background
Numerous studies have yielded high correlations between time
courses of a
number of different climatic phenomena and historical trends of
various
measures of solar activity (see, for example, the many entries
under Solar
Climatic Effects in our Subject Index). It is difficult,
however, for
certain scientists to believe that earth's thermal and hydrologic
cycles
could be so strongly influenced by so weak an influence as solar
forcing
appears to be in terms of its degree of variability. Hence,
the quest to
discover how weak solar signals could be sufficiently amplified
to produce
the many intriguing climatic histories that appear to be the
offspring of
solar variability has become somewhat of a Holy Grail for a major
branch of
climatology.
What was done
Noting that "solar magnetic activity exhibits chaotically
modulated cycles
... which are responsible for slight variations in solar
luminosity and
modulation of the solar wind," the authors attack the solar
forcing of
climate problem by means of a model in which the solar dynamo and
earth's
climate are represented by low-order systems, each of which in
isolation
supports chaotic oscillations but which when run together
sometimes
resonate.
What was learned
The authors determined that "solutions oscillate about
either of two fixed
points, representing warm and cold states, flipping sporadically
between
them." They also discovered that a weak nonlinear
input from the solar
dynamo "has a significant effect when the 'typical
frequencies' of each
system are in resonance."
What it means
The authors' findings are best stated in their own words:
"It is clear that
the resonance provides a powerful mechanism for amplifying
climate forcing
by solar activity." Hence, there need no longer be any
reluctance to accept
as fact the observation that the many correlations that have been
documented
between solar variability and the time histories of various
climatic
phenomena do indeed have a cause that is of extraterrestrial
origin.
Copyright © 2000. Center for the Study of Carbon Dioxide
and Global Change
================
(7) MORE EVIDENCE FOR SOLAR-OUTPUT MODEL OF CLIMATE CHANGE
Geophysical, archaeological, and historical evidence support a
solar-output
model for climate change. Perry CA, Hsu KJ. PROCEEDINGS OF THE
NATIONAL
ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 97: (23)
12433-12438 NOV
7 2000
Although the processes of climate change are not completely
understood, an
important causal candidate is variation in total solar output.
Reported
cycles in various climate-proxy data show a tendency to emulate a
fundamental harmonic sequence of a basic solar-cycle length (11
years)
multiplied by 2(N) (where N equals a positive or negative
integer). A simple
additive model for total solar-output variations was developed by
superimposing a progression of fundamental harmonic cycles with
slightly
increasing amplitudes. The timeline of the model was calibrated
to the
Pleistocene/Holocene boundary at 9,000 years before present. The
calibrated
model was compared with geophysical. archaeological. and
historical evidence
of warm or cold climates during the Holocene. The evidence of
periods of
several centuries of cooler climates worldwide called
"little ice ages,"
similar to the period anno Domini (A.D.) 1280-1860 and
reoccurring
approximately every 1,300 years, corresponds well with
fluctuations in
modeled solar output. A more detailed examination of the climate
sensitive
history of the last 1,000 years further supports the model.
Extrapolation of
the model into the future suggests a gradual cooling during the
next few
centuries with intermittent minor warmups and a return to near
little-ice-age conditions within the next 500 years. This cool
period then
may be followed approximately 1,500 years from now by a return to
altithermal conditions similar to the previous Holocene Maximum.
Addresses:
Perry CA, US Geol Survey, Lawrence, KS 66049 USA.
US Geol Survey, Lawrence, KS 66049 USA.
Tarim Associates, CH-8006 Zurich, Switzerland.
Copyright © 2000 Institute for Scientific Information
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reflect the opinions, beliefs and viewpoints of the moderator of
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