PLEASE NOTE:
*
CCNet 40/2001 - 13 March 2001
------------------------------
"Might I suggest an interim "solution" to the
Pluto Problem. [...]
Label the mnemonic "Solar System Objects", add the
asteroids and
comets, and now you can teach the various classes of objects -
Rocky,
Gassy, Icey:
"Mother Very Thoughtfully Made A Jelly Sandwich Under No
Protest, Cowabunga!!"
--Ted Brattstrom, Hawaii, 12 March 2001
"I hope that Conference participants will forgive me my late
coverage of the P-T extinction event press conference held by
NASA. Those
who watched the live stream of the press conference no doubt were
of
the opinion that I looked and sounded like someone who had just
been
in an auto accident; in fact, I was someone who had just been in
an auto
accident. While driving into Washington for the event I was
struck
from behind by a fellow who was a little more interested in where
he
was going than where he was; [...] Well, one thing is certain: if
this
test by Becker and Poreda turns out to be reliable, it is going
to
fundamentally change our view of the universe and our place in
it. As for
myself, if this test is able to provide definitive proof of the
occurence of some recent historical cometary impacts, this will
mean
that in the future there will be a whole lot less nonsense we
will all
have to put up with. And if that is the case, the loss of the
Benz will
become a minor inconvenience."
--EP Grondine, 12 March 2001
(1) VOLCANOES MAY HAVE MELTED ICE, PRODUCING WATER ON MARS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(2) SOME LIFE FORMS REBOUNDED QUICKLY AFTER K/T MASS EXTINCTION
Andrew Yee <ayee@nova.astro.utoronto.ca>
(3) THIRD EUROPEAN CONFERENCE ON SPACE DEBRIS
ESA <esaweb@esa.int>
(4) LUNAR PROSPECTOR PROVIDES A WORLD OF DATA
Andrew Yee <ayee@nova.astro.utoronto.ca>
(5) MAD COWS, FOOT & MOUTH DISEASE, & GHOST
TELESCOPES...?
Alain Maury <alain.maury@obs-azur.fr>
(6) NOT JUST LONDON 'WIPED OUT'
Michael Paine <mpaine@tpgi.com.au>
(7) AN INTERIM 'SOLUTION' TO THE PLUTO PROBLEM
Ted Brattstrom <tbrattst@k12.hi.us>
(8) HOW DOES AN ASTEROID ACQUIRE A SATELLITE?
Tom Van Flandern <metares@mindspring.com>
(9) A NEW TEST FOR COMETARY IMPACTS?
E.P. Grondine <epgrondine@hotmail.com>
(10) MEGA IMPACTS & THEIR CONSEQUENCES
Peter Snow <p.snow@xtra.co.nz>
============
(1) VOLCANOES MAY HAVE MELTED ICE, PRODUCING WATER ON MARS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
News Services
University at Buffalo
State University of New York
Buffalo, New York
Contact: Ellen Goldbaum, goldbaum@buffalo.edu
Phone: 716-645-5000 ext 1415
Fax: 716-645-3765
Release date: Monday, March 12, 2001
Mars' Volcanoes May Have Melted Ice, Producing Water Necessary
for "Life" on
Red Planet
HOUSTON -- Two of the oldest volcanoes on Mars, which have been
active for
3.5 billion years, are providing clues to the possibility of life
on the
planet, according to preliminary analysis by University at
Buffalo
geologists of new data from the Mars Orbiter Camera (MOC) and the
Mars
Orbiter Laser Altimeter (MOLA), currently orbiting the planet.
The scientists are presenting their results here today (March 12,
2001) at
the 32nd Lunar Planetary Science Conference.
Located in the southern hemisphere of Mars, the volcanoes, named
Tyrrhena
Patera and Hadriaca Patera because they look like overturned
saucers (patera
is Latin for saucer), may still be active, said Tracy Gregg,
Ph.D., UB
assistant professor of geology and principal investigator.
"What's most intriguing about these volcanoes is that they
are surrounded by
channels," said Gregg. "Of all the volcanoes on Mars,
these volcanoes have
the largest and greatest numbers of channels associated with
them,
indicating that there was a lot of water around when they were
forming,
though there doesn't appear to be any around now."
She noted that the presence of life on Mars would require water,
which
currently is impossible because of the planet's frigid climate.
Gregg said that the channels, now essentially dry riverbeds, may
have formed
because the volcanoes, which act as giant thermal-energy units,
could have
melted ice on the ground. The water would have flowed downhill,
away from
the volcano's center, carving the channels.
"The combination of the heat and energy from the volcanoes
and the liquid
water makes conditions ripe for the evolution of life, at least
as we
understand it on Earth," said Gregg.
She added that volcanoes also are a source of many of the
essential
chemicals that may be necessary for the evolution of biological
organisms.
Gregg and her colleagues are basing the preliminary analysis of
new data
gathered by the MOC and the MOLA. The data -- high-resolution
pictures taken
by the camera -- are transmitted by radio to Earth. The
scientists then
download them from the Malin Space Science Systems Web site at
http://www.msss.com .
"The MOC is a very high-resolution camera that allows us to
see features on
Mars as small as 1 meter across, so we can start to see some
really
significant things, like individual boulders and piles of
sediment, which is
allowing us to really piece together Martian history," she
said.
The MOLA provides very detailed topography, measuring height
differences as
small as 1-2 centimeters, she added.
"When this mission is complete, we'll know the surface of
Mars to within 1
meter," Gregg said. "There are areas on Earth we don't
know that well, such
as Antarctica and the entire ocean floor."
As more data pour in from this mission, Gregg and her colleagues
will be
continuing to analyze them, trying to learn more about how
evidence of water
on Mars may provide clues to questions about whether or not life
has existed
on the red planet.
Gregg's research is funded by the Planetary Geology and
Geophysics Division
of NASA.
IMAGE CAPTION:
[ http://www.buffalo.edu/scripts/newnews/index.cgi?article=marsvolcan
] The
presence of gullies along the sides of volcanos on Mars (above)
indicates
the planet once may have held water, according to UB geologist
Tracy Gregg.
============
(2) SOME LIFE FORMS REBOUNDED QUICKLY AFTER K/T MASS EXTINCTION
From Andrew Yee <ayee@nova.astro.utoronto.ca>
Media Relations
Caltech
Contact: Robert Tindol, (626) 395-3631
3/8/2001
Life rebounded quickly after collision 65 million years ago that
wiped out
dinosaurs
PASADENA, Calif. -- Though the dinosaurs fared poorly in the
comet or meteor
impact that destroyed two-thirds of all living species 65 illion
years ago,
new evidence shows that various other forms of life rebounded
from the
catastrophe in a remarkably short period of time.
In the March 9 issue of the journal Science, a team of
geochemists reports
that life was indeed virtually wiped out for a period of time,
but then
reappeared just as abruptly only 10,000 years after the initial
collision.
Further, the evidence shows that the extinctions 65 million years
ago, which
mark the geologic time known as the Cretaceous-Tertiary (K-T)
boundary, were
most likely caused by a single catastrophic impact.
"There's been a longstanding debate whether the mass
extinctions at the K-T
boundary were caused by a single impact or maybe a swarm of
millions of
comets," says lead author Sujoy Mukhopadhyay, a graduate
student at Caltech.
"In addition, figuring out the duration of the extinction
event and how long
it took life to recover has been a difficult problem."
To address both questions, Mukhopadhyay and his colleagues
measured the
amount of cosmic dust in the sediments of an ancient sea bed
which is now
exposed on land about 100 miles north of Rome. In particular they
focused on
a two-centimeter-thick clay deposit that previously had been
dated to about
65 million years ago. The base of this clay deposit corresponds
to the date
of the extinction event.
The clay deposit lies above a layer of limestone sediments, which
are
essentially the skeletons of microscopic sea life that settled at
the bottom
of the ancient sea. The limestone deposit also contains a certain
percentage
of clay particles, which result from erosion on the continents.
Finally,
mixed in the sediments is extraterrestrial dust that landed in
Earth's
oceans and then settled out. This dust carries a high
concentration of
helium-3 (3He), a rare isotope of helium that is depleted on
Earth but
highly enriched in cosmic matter.
The lower limestone layer abruptly ends at roughly 65 million
years, since
the organisms in the ocean were suddenly wiped out by the impact
event.
Thus, the layer immediately above the limestone contains nothing
but the
clay deposits and extraterrestrial dust that continued to settle
at the
bottom of the ancient sea. Immediately above the two-centimeter
clay deposit
is another layer of limestone deposits from microorganisms of the
sea that
eventually rebounded after the catastrophe.
In this study, the researchers measured the amount of 3He in the
sediments
to learn about the K-T extinction. They reasoned that a gigantic
impact
would not change the amount of 3He in the clay deposit. This is
because
large impacting bodies are mostly vaporized upon impact and
release all
their helium into the atmosphere. Because helium is a light
element, it is
not bound to Earth and tends to drift away into space. Therefore,
even if a
huge amount were brought to Earth by a large impact, the 3He
would soon
disappear and not show up in the sedimentary layers.
In contrast, 3He brought to Earth by extraterrestrial dust tends
to stay
trapped in the dust and not be lost to space, says Kenneth
Farley, professor
of geochemistry at Caltech and coauthor of the paper. So 3He
found in the
limestone and the clay deposits came from space in the form of
dust.
Based on the 3He record obtained from the limestones, the
researchers
eliminated the possibility that a string of comets had caused the
K-T
extinctions. Comets are inherently dusty, so a string of them
hitting Earth
would have brought along a huge amount of new dust, thereby
increasing the
amount of 3He in the lower limestone deposit.
But the Italian sediment showed a steady concentration of 3He
until the time
of the impact, eliminating the possibility of a comet swarm. In
fact, the
researchers found no evidence for periodic comet showers, which
have been
suggested as the cause of mass extinction events on Earth.
Mukhopadhyay and his colleagues reason that because the
"rain-rate" of the
extraterrestrial dust from space did not change across the K-T
boundary, the
3He concentration in the clay is proportional to the total
depositional time
of the clay. "It's been difficult to measure the time it
took for this
two-centimeter clay layer to be deposited," says Farley.
The researchers conclude that the two-centimeter clay layer was
deposited in
approximately 10,000 years. Then, very quickly, the tiny
creatures that
create limestone deposits reemerged and again began leaving their
corpses on
the ocean bed. The implication is that life can get started again
very
quickly, Farley says.
Thus the study answers two major questions about the event that
led to the
extinction of the dinosaurs, says Mukhopadhyay. In addition to
Mukhopadhyay
and Farley, the paper is also authored by Alessandro Montanari of
the
Geological Observatory in Apiro, Italy.
Related Links
* Dr. Ken Farley, Associate Professor of Geochemistry
http://www.gps.caltech.edu/faculty/farley/
* The Division of Geological and Planetary Sciences at Caltech
http://www.gps.caltech.edu/
* Science
http://www.sciencemag.org/
============
(3) THIRD EUROPEAN CONFERENCE ON SPACE DEBRIS
From ESA <esaweb@esa.int>
Nr. 14-2001 - Paris, 12 March 2001
Third European Conference on Space Debris
The European Space Agency is hosting the third European
Conference on Space
Debris from 19 to 21 March at ESOC, its European Space Operations
Centre in
Darmstadt, Germany. The British, French, German and Italian space
agencies
(BNSC, CNES, DLR, ASI), the Committee on Space Research (COSPAR),
and the
International Academy of Astronautics (IAA) are co-sponsoring
this event,
which will draw over 200 experts from all over the world.
While the use of space is expanding in nearly all areas - e.g.
telecommunication, navigation, Earth observation, science - space
debris is
of growing concern as a threat to manned and unmanned
spaceflight. The
purpose of the conference is to provide a forum for presentations
of results
from research topics ranging from ground- and space-based
techniques for
detection of orbital debris, trends in the orbital debris
environment in Low
Earth Orbit and the geostationary ring, the design of protective
shields, to
the removal of debris by tethers.
The aspects that will be discussed include methods and computer
tools to
predict the growing number of man-made objects in space, analysis
of
material returned from space, risks run by satellites in
low-Earth and
geostationary orbit, risks on the ground from reentering objects,
standards
addressing safety and mitigation of space debris, and legal
issues.
The conference programme can be found at the ESA website at:
http://www.estec.esa.nl/pr/conferences/conferencelist.php3
On 21 March a round table discussion will address mitigation
measures and
their application. The topicality of this theme is underlined by
the
deliberations on space debris at the Scientific and Technical
Subcommittee
of the United Nations Committee on the Peaceful Uses of Outer
Space
(UNCOPUOS) where protection and preventive measures play a key
role.
The conference will be followed on 22/23 March by the 19th
meeting of the
Inter-Agency Space Debris Coordination Committee (IADC), at DLR
in Cologne,
Germany.
IADC currently has 11 members (founder members: ESA, NASA, the
Russian
Aviation and Space Agency, Rosaviakosmos, and Japan), which will
exchange
results on space debris research, identify options for space
debris
mitigation, and promote joint research activities.
Journalists are welcome to attend the third European Conference
on Space
Debris. For more information or requests for accreditation,
please contact
the Public Relations Office at ESOC, Darmstadt (Germany), Tel:
(0)49.6151.90.2696/2459 - Fax: (0)49.6151.90.2961 or the
conference
organisation: (0)49.6151.90.2270.
==========
(4) LUNAR PROSPECTOR PROVIDES A WORLD OF DATA
From Andrew Yee <ayee@nova.astro.utoronto.ca>
Los Alamos National Laboratory
Contact:
Shelley Thompson, shelley@lanl.gov,
(505) 665-7778
01-029
Lunar Prospector provides a world of data
LOS ALAMOS, N.M., March 12, 2001 -- This week scientists from The
Department
of Energy's Los Alamos National Laboratory present their latest
findings
from NASA's Lunar Prospector mission at the Lunar and Planetary
Science
Conference in Houston, Texas.
"Lunar Prospector has revolutionized our view of the Moon --
we just didn't
realize how much it revolutionized it. And there is a whole
community of
people out there in the planetary science world that is excited
about and
interested in the Lunar Prospector data," said Rick Elphic,
a Los Alamos
scientist.
The Los Alamos studies include data on Moonquake activity,
further
confirmation of the presence of water-ice on the moon, and
mapping of iron
and titanium using gamma-rays emitted when cosmic rays slam into
the lunar
surface.
Los Alamos scientists built three of the five instruments that
were aboard
the Lunar Prospector spacecraft that orbited the Moon for nearly
19 months
gathering data, and then was intentionally crashed in the Moon's
south pole
in a final attempt to extract additional information about water
on the
Moon.
The data gathered by the Lunar Prospector and analyzed by Los
Alamos
scientists also provided the first global elemental lunar study
to date.
"You can't take samples of just a few locations on the Moon,
like the Apollo
missions did, and say you know the composition of the whole Moon.
It would
be like taking a rock from Paris and Los Angeles and a snap shot
of Tokyo
and saying you know everything about Earth's composition. It's
like a
detective story -- you have to put all of the pieces of
information together
to see the whole picture," David Lawrence, a Los Alamos
researcher, said.
Los Alamos scientists present a few pieces from this puzzle this
week at the
conference. The scientific goals for the Lunar Prospector were to
answer
long-standing questions about the Moon, its resources --
including water --
its structure, and its origins.
Los Alamos scientists at the conference include Lawrence and Tom
Prettyman,
who present the first Lunar Prospector Gamma-Ray Spectrometer
measurements
of lunar iron abundance. Elphic and Prettyman, who present
titanium data
that suggest previous measurements were twice as high as the
actual
abundance. Olivier Gasnault, who presents neutron data that
correlates the
atomic mass of the soil to neutron flux. William Feldman, who
provides
further evidence that the enhanced hydrogen abundance at the
lunar poles is
in the form of water ice. Stefanie Lawson, who presents the first
Alpha-Particle Spectrometer measurements on tectonic activity and
Elphic
also presents computer simulation data that confirm actual
measurement
techniques.
Lawrence's gamma-ray spectrometry data give the first overall
iron
composition measurements of the entire lunar surface. Iron
abundance is a
crucial piece in understanding lunar composition because iron is
a major
constituent of all lunar rocks, and iron abundance reveals
information about
how the Moon formed and changed over time.
Both iron and titanium are fundamental elements in the lava -- or
maria
flood basalt -- plains on the Moon's surface that are seen from
Earth as the
"dark spots" of the Moon.
The Department of Defense's earlier Clementine mission measured
iron and
titanium by using ultraviolet, visible, and near-infrared
spectroscopy and
concluded there is more iron and titanium in the dark spots and
less in the
light-colored spots. "Their overall measurements of the
entire Moon's
elemental composition is based on empirical relationships. They
empirically
identified that a certain reflectance correlates with a given
abundance. But
this correlation was based upon the limited soil samples gathered
on the
Apollo missions," Lawrence said.
Lawrence's results show that the Clementine abundance
measurements for
returned sample locations agree quite well with the Lunar
Prospector's
gamma-ray spectrometer measurements; however the abundance
derived by
Clementine in locations not sampled by Apollo will need to be
revised based
on the Lunar Prospector gamma-ray spectrometer data.
Elphic's Neutron Spectrometer data on the concentration of
titanium in the
maria flood basalt regions contradicts the concentrations
inferred by the
correlation drawn between the Clementine and Apollo missions.
Elphic's
findings indicate there is half as much titanium in the basalt
regions as
the previous data suggested.
"These results have potential ramifications for two areas.
First, for
understanding the source regions and history of lunar basaltic
volcanism and
secondly for the future colonization of the Moon. If we intend to
use
indigenous resources when we colonize it's important to know what
we have
available and where we can find it," Elphic said.
"No one has ever looked at the Moon -- or any other
planetary body -- with
'neutron eyes.' It is a whole different way of seeing things and
it is very
exciting," said Elphic. Lunar Prospector carried neutron
detectors that
measured neutrons in three energy ranges emitted by the lunar
surface.
In another study, Gasnault determined the relationship between
the fast
neutron fluxes emitted from the lunar surface and the average
weight --
atomic mass -- of the soil. "The calculations show that the
number of
neutrons produced is proportional to the atomic mass of the
soil," Gasnault
said.
The first neutrons that escape after the lunar soil is hit by
cosmic rays
are indicative of the composition of the soil. Different
elements, when hit
by cosmic rays, will produce a different number of neutrons,
which will
eventually reach different energies called fast, thermal or
epithermal.
Neutrons termed fast neutrons are indicative of iron and
titanium. This
information helps determine the elemental composition of the
soil.
"The remarkable difference in composition between the two
faces of the Moon
is surprising for a small planet. This is one of the great
mysteries of the
Moon," said Gasnault.
Gasnault also worked out a combined analysis of fast neutron data
and
thorium abundance on the lunar surface. Thorium is a subsurface
material
brought to the surface by meteor impacts and volcanic activity.
Using this
analysis Gasnault believes they have found another impact basin
near the
large Imbrium basin.
Feldman's Neutron Spectrometer data coupled with calculations of
sublimation
processes of hydrogen compounds confirmed previous indications
that the
hydrogen in the permanently shaded regions of the lunar poles is
in the form
of water ice.
Sublimation is the process by which solids are transformed
directly to the
vapor state without passing through the liquid phase.
"Sublimation is the only mechanism that can account for
observed differences
between the hydrogen content of sunlit and permanently shaded
craters near
lunar poles," Feldman said.
The partially shaded -- or partially sunny -- regions of the
poles reach
minus 234 degrees Fahrenheit but the permanently shaded regions
remain at
minus 315 F. Going above or below minus 279 F determines whether
the
water-ice will sublimate or be trapped forever. So in the
partially sunny
regions of the poles the water-ice will sublimate, whereas in the
permanently shaded regions it will be trapped indefinitely.
Hydrogen by
itself is not stable at these temperatures and will only remain
if it forms
bonds -- becomes water-ice for example -- so the hydrogen
detected in the
permanently shaded regions of the poles must be in the form of
water-ice.
It is estimated that each pole may contain up to one billion tons
of frozen
water ice spread throughout the soil.
Feldman said, "These data suggest an exciting scenario for
lunar
colonization. The polar regions that border the permanently
shaded craters
are also in the sunlight 80-85 percent of the time and would make
optimal
space station sites. The stations would have access to the
water-ice and the
sunlight would provide solar power. And by being near the poles
you see
Earth most of the time, which means you can communicate."
Lawson presents measurements of near-surface uranium gained from
the
Alpha-Particle Spectrometer data. The Alpha-Particle Spectrometer
measured
radon and polonium gasses that escaped from below the surface
through
conduits created by tectonic, or Moonquake, activity. Polonium is
a decay
product of radon, which in turn is a decay product of uranium.
When
detected, they both indicate the presence of uranium.
Elphic presents a poster on computer simulations used to model
neutron
emissions from the surface, their flight into space and their
detection by
Lunar Prospector spectrometers. "The good news about these
simulations,"
Elphic said, "is that they agree with measurements from the
Lunar
Prospector. If they didn't it would have raised doubts about our
data."
The three instruments built by Los Alamos scientists were the
Neutron
Spectrometer designed to measure the surface abundance of lunar
materials
with special emphasis placed on the search for polar water-ice
deposits as
implied by hydrogen abundances; the Gamma-Ray Spectrometer
designed to
provide maps of the major and trace elements in the lunar
surface; and the
Alpha-Particle Spectrometer designed to measure the history of
gas release
events on the Moon.
Los Alamos' Lunar Prospector team of the Space and Atmospheric
Sciences
Group submitted 15 abstracts to the conference and is represented
by nine
scientists presenting both posters and talks and attending
meetings.
Prospector is a NASA Discovery Mission that places emphasis on
science and
"faster, better, cheaper" mission design and
development.
==========================
* LETTERS TO THE MODERATOR
==========================
(5) MAD COWS, FOOT & MOUTH DISEASE, & GHOST
TELESCOPES...?
From Alain Maury <alain.maury@obs-azur.fr>
Dear Benny
I must say that despite this tongue in cheek title and the fact
that the UK
government statement did not have a cheque attached to it, I am
quite
impressed by the achievements obtained so quickly in Britain. How
many
people were there in the 1980s who knew about the nature of the
impact
hazard? How many were there in the 1990s? How many
astronomers/astrophysicist
still consider this field as non-scientific or a borderline joke?
Let's face
it, if some of our colleagues knew (I mean the average astronomer
can access
the required literature much more easily than a typical British
Lord), we
would see more of them joining our ranks, because this
is where the really hot stuff is happening (I mean it is useful,
it has a
lot of ramifications in many other field of sciences, including
social
sciences, it is were our future is, we will visit and use those
places).
I can't help to think that in 1994, there was an unknown amateur
astronomer
by the name of Jay Tate, watching Jupiter being hit by SL9, who
was asked by
a neighbor what would happen on earth if such a thing were to hit
us. "I
don't know but I'll find out" was his answer. The rest is
history.
I was also impressed by the way the situation has been handled by
British
politicians. The sky is the last place where we have myths. Santa
Claus, a
place for us after death (with wings and all), God's house?, some
place far
away in a distant galaxy?, bald places where bold people go? a
big bang
prone thing? But how many British Lords would be able to point
Jupiter or
Venus in the night sky, how many have ever observed a real
asteroid or are
expert in the cratering rates in the solar system?
Taken all these factors into account, and the reaction of many
astronomers
who should know better (I mean if what is obvious to us was
obvious to
them), we would even not have to lobby politicians to take
action. No, the
reaction of the British government is brilliant and to be
applauded. Its
response, so far, is a far cry from the recommendations of the
Task Force it
set up - but how many governments have set up a NEO Task Force in
the first
place? It is an important step, taken with the seriousness the
issue
requires and without our own enthusiasm of
course; but to be honest, could we have expected more than that
in such a
short time? In fact, taken the current situation in the UK (see
the title),
and compared to the fact that earthquakes alone have already
claimed several
thousands of deaths since the beginning of the year, taken into
account the
small (at a government level) amount of funding that the subject
requires,
it is quite impressive that it is discussed at such a high
political level.
Participating in the current NEO inventory require some means,
and in order
to get those means, we have either to get them from our fellow
astronomers
(like in the US through NASA), directly through political
lobbying (UK tentative) or through private funds ( Spaceguard
Foundation ?).
Either way is not easy because we miss the contact with these
groups at both
the cultural and language level. Astronomers are for the vast
majority still
giggling about it. And being a hazard protection affair (even
though a non
conventional one), it is not sure that astronomers have to pay
for it. If it
were not through Mr Opik, I believe the UK effort would have been
vain, and
the handling of many "asteroid scares" makes me think
we still have a lot to
do as far as communicating with the public in a clear, factual
fashion.
In France, it is clear that funding would have to come from the
astronomical
funding, and the handful of people really convinced of the
seriousness of
the task (or willing to compromise their scientific
respectability) compared
to about 1000 other astronomers who have some personal ideas on
how to use
this limited funding makes me feel that the situation is somewhat
hopeless.
I believe a truly European initiative, i.e. not depending of the
national
level, is the way to go. There are enough European organisations
(ESO, ESA,
Brussels) to make it happen. I would be however interested to see
how other
Europeans governments were to react if they were asked. It will
be a real
"tour de force" to make it happen here too. So who is
going to join in ?
Alain Maury
==============
(6) NOT JUST LONDON 'WIPED OUT'
From Michael Paine <mpaine@tpgi.com.au>
Dear Benny,
The BBC report on the House of Lords debate (CCNet 12 March)
mentioned the
consequences of a 1km diameter asteroid hitting central London
"Had it
struck the Palace of Westminster, it would have wiped out much of
London."
An impact by a 1km diameter stony asteroid travelling at 22km/s
would
typically produce a crater 20km across, so most of London would
be a hole in
the ground. Everything out to a radius of about 150km would have
been burnt
or blasted like the centre of Hiroshima. The blast wave would
have
knocked trees over and imploded window glass at deadly speed some
300km
away. The rest of the UK, and much of Europe would have been
covered in a
dense dark cloud turning day into night, like the local effects
of Mt
Pinatubo in the Phillipines. Massive earthquakes and hurricanes
would
probably have finished off any remaining infrastructure in the
region.
(see http://www4.tpg.com.au/users/tps-seti/climate.htm
for references).
Fortunately the odds of this happening TO LONDON in the next
century are
roughly 1 in 3 million (but still much better odds than winning
the
lottery).
Also I have just updated my craters/extinctions graph at
http://www4.tpg.com.au/users/tps-seti/crater.html
regards
Michael Paine
==================
(7) AN INTERIM 'SOLUTION' TO THE PLUTO PROBLEM
From Ted Brattstrom <tbrattst@k12.hi.us>
Aloha -
In response to "(8) PEERING AT PLUTO FROM PATERSON"
Might I suggest an interim "solution" to the Pluto
Problem...
While many learned "My very educated mother just served us
nine pizzas" to
memorize the Solar System, in my elementary school days I
learned, thanks to
Robert Heinlein, "Mother Very Thoughtfully Made A Jelly
Sandwich, Under No
Protest".
The difference, T for Terra instead of E for Earth is small.
However, the
Big difference, and related to the issue of "Pluto is a
KBO" and our
favorite NEOs, A is introduced for the Asteroids. By adding in
the asteroids
we can discuss the different classes of Solar System objects,
though I
suspect our cometary colleagues would like some reference, so
perhaps we can
add "Cowabunga" to the end of the mnemonic.
So, two suggestions....
Label the mnemonic "Solar System Objects", add the
asteroids and comets, and
now you can teach the various classes of objects - Rocky, Gassy,
Icey.
And I'll bet those 5th and 6th graders will have no problem with
it. (Adding
or modifying information is always easier than subtracting it!)
Solar System Objects, in rough order:
"Mother Very Thoughtfully Made A Jelly Sandwich Under No
Protest,
Cowabunga!!"
Aloha - Ted Brattstrom (ted@hawaii.edu
- tbrattst@hi.k12.us)
============
(8) HOW DOES AN ASTEROID ACQUIRE A SATELLITE?
From Tom Van Flandern <metares@mindspring.com>
In response to the current note by Singer about asteroid
satellites, I have
sent the following short notes to other correspondents who asked
me about
this. -|Tom Van Flandern|-
Consider the difference between collisional break-ups and
explosional
break-ups of parent bodies. Fragments from a collision do *not*
have the
property described by Singer because any two fragments from a
collision must
diverge linearly with distance from the collision site (near the
surface), whereas the gravitational sphere of influence (SOI)
enlarges
linearly with distance from the center of the parent body (a
greater
distance, and therefore a slower rate). So the SOI can never
enlarge fast
enough from a collision to engulf other fragments.
By contrast, in a central explosion, some fragments are ejected
with higher
speeds than others. The slower fragments not only increase their
mutual
separations linearly with distance from the center of the parent
body, but
in addition, the SOI increases *faster* than linear with
distance because a substantial fraction of the parent body mass
is located
in a spherical shell outside the slower fragments. (Mass in a
uniform
spherical shell produces no gravitational force in its own
interior.) So the
SOI goes up with increasing distance *and* with decreasing
effective mass
remaining interior to the fragments, allowing the SOI to engulf
other nearby
fragments.
Tom Van Flandern
=============
(9) A NEW TEST FOR COMETARY IMPACTS?
From E.P. Grondine <epgrondine@hotmail.com>
Hello Benny -
I hope that Conference participants will forgive me my late
coverage of the
P-T extinction event press conference held by NASA. Those who
watched the
live stream of the press conference no doubt were of the opinion
that I
looked and sounded like someone who had just been in auto
accident; in fact,
I was someone who had just been in an auto accident. While
driving into
Washington for the event I was struck from behind by a fellow who
was a
little more interested in where he was going than where he was;
fortunately,
my 1976 Mercedes Benz 240D worked exactly as advertised,
absorbing the
collision's force, and I was left shaken, though not seriously
hurt, by the
accident. If you're going to be in one of these things, I
heartily endorse
being in it in a Mercedes Benz (http://www.mercedesbenz.com).
The final total cost to me of providing this coverage is not yet
known, but
the other fellow's insurance company, GEICO, has offered me so
far the
magnificent sum of $1,486.96 for my 240D. This is
apparently not their
final offer, and I am hopeful that my coverage in the
future will not be
hindered by the necessity of my taking time out to sue them.
Whatever the outcome, the trip into Washington will have been
worth it, as I
had a chance to talk with Dr. Robert J. Poreda, who conducted the
fullerene
extraction and isotopic gas measurements, as well as with Dr.
Luann Becker,
who headed the project. Dr. Poreda assured me that he is
willing to freely
share with researchers at other laboratories the technniques
which the team
developed for buckeyball extraction and processing. Conference
participants
who wish to bring these techniques to their laboratories, or who
may have
samples for study, may contact him at Robert J. Poreda, Associate
Professor,
Dept. of Earth and Environmental Sciences, 227 Hutchinson Hall,
Rochester,
New York, 14627, telephone 716-275-0051, e-mail address
rjpo@db1.rochester.edu.
Iain Gilmore has raised here the question of whether these cosmic
fullerenes
are indicators of asteroid impact, and despite my impaired mental
state I
raised the same question during the press conference: Could this
technique
be used to recover evidence of both asteroid and comet impact
down to the
size of 50 to 350 meters? Poreda was of the opininon that
it could, but
here I will differ with him, and side with Iaian: I believe
that while the
technique can be used to detect evidence of impact by comets both
fresh and
dead, my guess at this point is that some types of impactors did
not deliver
these cosmic fullerenes.
The issues involved go the heart of cosmology, and there is no
doubt that
the recovery ( and the lack of recovery) of these cosmic
fullerenes from
different cosmic objects is going to decide farily clearly a
number of
issues involving the formation of our solar system. My
current guess is
that we are looking at 4 major classes of objects here: comets;
"dead"
comets (ones exhausted of volatiles); primitive objects condensed
out of the
original stream of super-heated matter; and finally objects
produced by the
destruction (3.9 Gya) of at least one major previously
differentiated
planetessimal; the rest of the objects most likely the result of
collisions
among objects of these 4 main classes. I am of the opinion
that much of the
weakness of our current understanding is based upon inferences
made by
incorrectly lumping these 4 classes together, along with the
subclasses -
but as I'm no cosmologist, like most laymen I will simply accept
whatever
those who are cosmologists tell me next...
What I am interested in is historical impacts and their effects
on man, and
that is why I am excited by this test: Dr. Poreda's methods of
extracting
and examining comet derived fullerenes may provide conclusive
evidence of
several historically recent impact events. Let's look at
the list of
candidates:
A SHORT LIST OF KNOWN AND SUSPECTED HISTORICAL IMPACTS
AS OF MARCH, 2001
While most, BUT NOT ALL, of the impact events listed here await
detailed
confirmation by field geologists, some of them are currently
known fairly
well.
CLASS 8:
"A collision capable of causing localized destruction. Such
events occur
somewhere between once per 50 years and once per 1000
years." (hoo boy, look
at those numbers...)
Suspected and Known:
ca. 1584 BCE Destruction of Hittite forces under T'e Hantilish
(Joshua impactor)?
ca. 520 BCE Destruction of Etruscan town of Volsinii?
ca. 1 BCE Brenham, Kansas (confirmed)
679 AD - Destruction of Colingiham Monastery?
ca. 800 AD - Impact in Baltic and death by local tsunami?
ca. 1000 AD (give or take a hundred years) - destruction of major
Native
American center along the Saint Lawrence River?
ca. 1321-1368 AD Erh River fall in China?
1450 AD - miss ("missed" people - no one killed) Wabar
1490 AD - Ch'ing-yang fall kills over 10,000 (possibly hail)?
(I can't find my copy of the list of what, 8?, small events of
the 1700's
and 1800's so laboriously assembled from obscure sources by one
industrious
researcher, and my apologies to him.)
1868 AD - miss near Pultusk, Poland
1908 AD - miss in Tunguska
1930 AD - miss in Brazilian jungle
1947 AD - miss at Sikhote Ailin in Kamchatka
1972 AD - miss in South West Pacific
CLASS 9:
"A collision capable of causing regional devastation. Such
events occur
between once per 1,000 years and once per 100,000 years."
Suspected:
ca. May 10, 2807 BCE - Masse sets this as the date of the Indian
Ocean
impact and resulting tsunami?
ca. 300 BCE - Destruction of Ainu? Jomon ends in southern Japan,
appearance
of Yayoi culture
ca. 500 AD - impact tsunami hits western Australia
580 AD - Destruction of Bordeaux region and city of Orleans?
585 AD - Destruction of "two islands in the sea"?
ca. 750 AD - Great Raft formation, Louisianna, but unknown if
caused by
impact, hurricane, or methane hydrate explosion
ca. 1200 AD - Bald Mountains impact event leads to migration of
Cherokee
into devastated area?
ca. 1500 AD - Australian Great Wall of Water, with collapse of
Polynesian
megalithic cultures on Ponhpei and elsewhere
CLASS 10:
"A collision capable of causing global climatic catastrophe.
Such events
occur once per 100,000 years, or less often."
Suspected and Known:
ca. 3114 BCE - Atlantic impact; Battle of Titans(?), tsunami
leading to
flood myths, Stonehenge I constructed, Mayan Calendar begins -?
ca. 2345 BCE - Ullikummi cometary impactor pretty much wipes out
Hurrians;
either climate shift occurs at same time, or dust loading
leads to
climate collapse and global starvation
ca. 2345 BCE? - Incineration of Harrapan city of Mohenjo Daro,
India; by
fragment of same comet?
ca. 2100 BCE - Rio Cuarto impact, climatic collapse, global
starvation
(confirmed)
ca. 1160 BCE - General migration in eastern Mediterranean follows
report by
observor from some distance away of loud noise and rush of air?
ca. 536 AD - Dust loading leads to sub-Roman times becoming
sub-Roman.
Global climate collpase and starvation. Possible
combination of
volcanic and cometary dust
I have also been informed by Richard Wade that initial data on
historical
impact events in Africa will be published in the very near
future.
AS IS well known by those involved in the expeditions to
Tunguska, it has
been extremely difficult to find indisputable evidence of
cometary
airbursts. But now there is an excellent chance that Poreda and
Becker's new
test will solve this problem in a definitive manner. Thus the
question
becomes: "Which candidates on the list of recent impacts are
most likely to
have been cometary impacts, rather than asteroid impacts, and now
may be
capable of being verified as such?" First off, the
impacts which are known
to have been asteroidal can be removed from the list; second,
those impacts
which produced tsunami, and where it wil be impossible to recover
soil
samples for analyis, may also be removed. That leaves the
following:
CLASS 8:
"A collision capable of causing localized destruction. Such
events occur
somewhere between once per 50 years and once per 1000
years."
Suspected and Known:
ca. 520 BCE Destruction of Etruscan town of Volsinii?
679 AD - Destruction of Colingiham Monastery?
ca. 1000 AD (give or take a hundred years) - destruction of major
Native
American center along the Saint Lawrence River?
1908 AD - miss in Tunguska
1930 AD - miss in Brazilian jungle
CLASS 9:
"A collision capable of causing regional devastation. Such
events occur
between once per 1,000 years and once per 100,000 years."
Suspected:
(ca. 300 BCE)- Destruction of Ainu? Jomon ends in southern Japan,
appearance
of Yayoi culture
580 AD - Destruction of Bordeaux region and city of Orleans?
ca. 750 AD - Great Raft formation, Louisianna, but unknown if
caused by
impact, hurricane, or methane hydrate explosion
ca. 1200 AD - Bald Mountains impact event leads to migration of
Cherokee
into devastated area?
CLASS 10:
"A collision capable of causing global climatic catastrophe.
Such events
occur once per 100,000 years, or less often."
Suspected and Known:
ca. 2345 BCE - Ullikummi cometary impactor pretty much wipes out
Hurrians;
either climate shift occurs at same time, or dust loading
leads to
climate collapse and global starvation
ca. 2345? - Incineration of Harrapan city of Mohenjo Daro, India;
by
fragment of same comet?
ca. 536 AD - Dust loading leads to sub-Roman times becoming
sub-Roman.
Global climate collpase and starvation. Possible
combination of
volcanic and cometary dust
Furthermore, running this test against soil samples from known
sites like
Meteor (Barringer) Crater and Rio Cuarto should provide key
information
about the cosmic fullerene content (or lack therof) of the
objects which
struck in those places. I asked Drs. Becker and Poreda if
the test could be
used against Tusguska, and both were of the opinion that it
could. Dr.
Poreda expressed concern about the recovery of samples from the
blast from
the bogs there.
What is even more exciting is that the test requires small soil
samples.
This may allow it to be used on samples from different locations
in North
Syria, which may allow the determination of both the center of
Ullikummi
impact and its size, and thus the total dust load it produced and
the
climatic consequences. And it may be that the same
techinque of analyzing
multiple samples might possibly be used to identify the exact
location of
the St. Lawrence impact.
One of the low points of the press conference was Chris Chyba's
statement
that devastating dust loads occur only every one million years or
so,
whereas many here suspect on well evidenced grounds that it is
much higher.
In particular reference to the AD 546 event, given that the the
test works
in parts per billion, it may be that it can be applied against
cores to
determine if the dust loads were volcanic or cometary in origin.
This
possiblity was also raised by Dr. Poreda in his response to my
initial
question during the press conference, and he thought it possible
that
evidence of the dust streams might be recovered.
Dr. Becker definitely wanted to work with cores, and spoke of her
frustration in getting funding for this work. It turned out that
NASA had
denied her request for funds for the analysis of P-T soil samples
several
times, and had only joined in after the US National Science
Foundation had
steeped forward. The NASA funding finally came from NASA's
Astrobiology and
Cosmochemistry programs, and the press release from University of
Washington
metioned Ted Bunch of the NASA's Ames Research Center, Moffett
Field, CA.
Clearly US researchers seeking funds for the analysis of samples
should
apply to the NSF; if the efficiency of this test is confirmed,
the USGS may
step in. It is also possible that the US Army Corps of
Engineers, who have
reponsibility for the Mississippi River, would like to know
whether the
Great Raft was formed by an impact or by a hurricane - this is an
important
question for the US, with large policy consequences for dealing
with
hurricanes. Finally, it wouldn't hurt to apply to NASA for money
either, if
for no other purpose than to call their attention to the impact
problem.
Another low point of the press conference was watching Dr.
Richard Bambach,
Professor Emeritus of Paleontology, Virginia Polytechnic
Institute,
Blacksburg (this is relatively local for me) trying to sort
through the
possible extinction mechanisms. His frustration is
understandable, and after
the televised portion I briefly discussed with him the
consequences of the
fact that no nuclear scientist was a member of the team. Without
having
someone available able to describe exteremely large explosions,
it is almost
impossible to understand the environment that occurs as a result
of them.
My discussion with Bambach yielded another item of interest.
During the
press conference, he had stated that such extinction events occur
every 100
million years or so, and I was curious as to whether this was in
reference
to all extinction events, or just to ones of sufficient
size. Afterwards,
when I asked Dr. Bambach if he was familiar with Clube and
Napier's work
which showed a 26 million year or so periodicy of extinction
events, and he
told me that he was unfamiliar with it in its entirety.
This brings me to a final topic which must be raised now. Clube
and Napier
have hypothesized that the passage of our Solar System through
the plane of
our galaxy the Milky Way every 26 million years or so has
dislodged comets,
which have then collided with the Earth and caused mass
extinctions. But
what if these extinction collisions are caused by asteroids on
the one hand,
and by comets on the other? Is it possible that the
gravitational
consequnces of the passage through the galactic plane have
altered the
orbits of both classes of objects on a roughly 26 million year
basis?
Well, one thing is certain: if this test by Becker and Poreda
turns out to
be reliable, it is going to fundamentally change our view of the
universe
and our place in it. As for myself, if this test is able to
provide
definitive proof of the occurence of some recent historical
cometary
impacts, this will mean that in the future there will be a whole
lot less
nonsense we will all have to put up with.
And if that is the case, the loss of the Benz will become a minor
inconvenience.
Best wishes to all,
EP
=========
(10) MEGA IMPACTS & THEIR CONSEQUENCES
From Peter Snow <p.snow@xtra.co.nz>
Dear Benny,
I have never seen any reference to the consequences of a major
asteroidal
impact with a planetary body that significantly alters the volume
of the
planet and consequently the mass, what effects that would have on
the
atmosphere and downstream from that the impact on extant plant
and animal
life on the gravitationally altered planet. Are you or the
group aware of
any such work?
Peter Snow
p.snow@xtra.co.nz
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