PLEASE NOTE:
*
CCNet 88/2001 - 19 July 2001
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* PLEASE NOTE THAT I WILL BE ON HOLIDAY FROM 23 JULY - 20 AUGUST
*
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"PREPARE to be afraid, very afraid. The Government has set
up a
special unit to find out when the next horseman of the apocalypse
will gallop through the neighbourhood. Killer asteroids, doomsday
plagues
and a morbid fear of something nasty lurking in the lab were once
the
sole preserve of the feverish minds of science fiction writers.
In the past
few days, however, the Government has announced that it will turn
to
sci-fi in a big way to anticipate catastrophes."
--Roger Highfield, The Daily Telegraph, 18 July 2001
"The mining of asteroids, space-based hotels, zero-gravity
manufacturing and medicine -- they're all part of the future
commercialization of space, according to a joint government and
industry
group that's developing the InterPlaNetary (IPN) Internet.
Starting this
year, with NASA funding, the IPN will roll out in pieces over the
next
several decades to support communications among spaceships,
robots and
manned and unmanned outposts in the solar system."
--Gary H. Anthes, CNN, 18 July 2001
(1) FIREBALL EXPLODES OVER NEW JERSEY
The Trentonian, 18 July 2001
(2) ANCIENT CITIES VANISHED INTO MUDDY MORASS
New Scientist, 18 July 2001
(3) WHO WILL SAVE US FROM DESTRUCTION? NEW TASK FORCE TO ASSESS
EVERY KNOWN
AND UNKNOWN (AND UNKNOWN UNKNOWN) HAZARD, DANGER, THREAT AND
POTENTIAL RISK
Daily Telegraph, 18 July 2001
(4) TIME TO DEMOTE PLUTO? MAYBE
The Columbo Dispatch, 15 July 2001
(5) INTERPLANETARY INTERNET IN THE WORKS
CNN, 18 July 2001
(6) EARTHQUAKES REVEAL DIAMONDS' ORIGINS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(7) SUPERVOLCANOES
Hermann Burchard <burchar@mail.math.okstate.edu>
(8) TUNGUSKA EXPEDITION
Andrei Ol'khovatov <olkhovatov@mtu-net.ru>
(9) PLANETARY DEFENSE: DIRECT HIGH-SPEED INTERCEPTION
Ulybyshev Y
(10) WOBBLING ASTEROIDS AND COMETS
Michael Efroimsky
(11) DIRECT SIMULATION OF METEOROIDS AND SPACE DEBRIS FLUX ON
LDEF
SPACECRAFT SURFACES
Jingqi Miao and J. P. W. Stark
(12) THE EUCRITE/VESTA STORY
Drake MJ
(13) LOW ALBEDOS AMONG EXTINCT COMET CANDIDATES
Fernandez YR, Jewitt DC, Sheppard SS
(14) FINAL ANNOUNCEMENT OF JAPANESE NEO WORKSHOP
Syuzo Isobe <isobesz@cc.nao.ac.jp>
(15) FIRST ANNOUNCEMENT: THE INSPIRATION OF ASTRONOMICAL
PHENOMENA
Rolf Sinclair <rolf@SANTAFE.EDU>
(16) AND FINALLY: NO VOLCANOES, NO EARTHQUAKES, BUT LOTS OF
CLOUDS. BRITISH
ENVIRONMENT ON MARS
Andrew Yee <ayee@nova.astro.utoronto.ca>
=============
(1) FIREBALL EXPLODES OVER NEW JERSEY
From The Trentonian, 18 July 2001
http://www.zwire.com/site/news.cfm?newsid=2099468&BRD=1697&PAG=461&dept_id=44551&rfi=6
UFO sightings at dusk, dawn
DAVE SOMMERS, Staff Writer July 18, 2001
Most UFO sightings in the New Jersey-Pennsylvania sky occur
either at dawn
or dusk when objects high up in the stratosphere, such as
airplanes or
meteorites, are more likely to refract sunlight back to earth,
astronomers
say.
That's one of the things that puzzles Kirk Alexander, director of
the
Amateur Astronomy Association of Princeton, who notes that
Sunday's unusual
sighting occurred in the middle of night.
Alexander said many UFO sightings turn out to be small meteors
which split
up, fall back into the stratosphere and burn brightly for several
minutes.
"The larger meteorites can explode and the pieces burn in
unison as they
fall through the atmosphere," he said.
That's basically the description the 70 or so people gave when
they
described the brightly burning lights they observed near Carteret
at 12:30
a.m. Sunday.
Alexander also noted that the cool, crisp weather last weekend
enabled
people to see for miles, something which can't happen onhazy
cloud-filled
nights.
"There have been incidents where aircraft eject small
objects out of their
exhaust which can been seen for miles," he said, adding one
more explanation
to the long list of possibilities.
The Amateur Astronomy Association group has 150 members. They
meet twice a
month, usually at one of the group's two observatories
inWashington Crossing
State Park in New Jersey or Jenny Jump, New Jersey.
"As astronomers, we try to look at these weird happenings as
a way to learn
something, and we usually do," he said.
©The Trentonian 2001
==========
(2) ANCIENT CITIES VANISHED INTO MUDDY MORASS
From New Scientist, 18 July 2001
http://www.newscientist.com/news/news.jsp?id=ns99991047
Stephanie Pain
Two ancient cities that once stood at the mouth of the Nile
vanished into a
morass of liquid mud when the river burst its banks, according to
an
analysis of the sediments in Egypt's Abu Qir bay.
The research suggests that the cities sank into the bay when
turbulent
floodwaters transformed the soft, unstable ground beneath them
into a soup
of sediment.
The disappearance of these cities has been blamed on earthquakes,
subsidence
and rising sea levels. But Jean-Daniel Stanley, a coastal
geoarchaeologist
at the Smithsonian Institution in Washington DC, blames the Nile.
"A powerful flood would bring a lot of water carrying a lot
of sediment -
enough to cause failure of the ground at the river mouth,"
says Stanley.
Prime location
The ruins of the two long lost Greek cities of Eastern Canopus
and
Herakleion were uncovered in 1999 and 2000 by marine
archaeologist Franck
Goddio of the European Institute for Underwater Archaeology in
Paris.
Hi-tech surveys of the seafloor revealed the substantial remains
of Eastern
Canopus 1.6 kilometres offshore and buried under five metres of
mud. The
city of Herakleion lies beneath seven metres of mud 5.4
kilometres from the
shore.
Today the nearest branch of the Nile lies more than 20 kilometres
to the
east of Abu Qir bay. But the surveys show that both cities once
stood at the
mouth of a now-extinct branch of the Nile - where they could
control
incoming vessels and tax goods being shipped upriver. "You'd
think the
Greeks would have thought twice about building on low, soft
sediment. But it
was clearly profitable," says Stanley.
Excavations at the two sites indicate that both cities were
damaged by
earthquakes before they disappeared. But this doesn't explain why
the land
subsided so catastrophically beneath them, says Stanley.
Liquefied earth
Slumping caused by a quake would be widespread in the bay.
Instead, it is
restricted to the margins of the lost river. Cores taken at the
site of
Eastern Canopus show clear signs of liquefaction - a process that
disrupts
the normal layers of sediment. "As the ground turned to
liquid some
buildings would sink in, others would be pushed up," says
Stanley. Collapse
would be rapid.
Stanley has pinpointed the flood that did for Eastern Canopus.
The discovery
of two Arabic coins dating from the 730s suggests the city had
not sunk by
then. Written records of the highs and lows of the Nile note
significant
flooding in 741-742 AD, with the river rising a metre higher than
the normal
flood level. This was almost certainly the flood that buried
Canopus, says
Stanley.
Analysis of cores taken around Herakleion this spring should soon
reveal
whether it suffered the same fate. The youngest artefacts from
the site date
from the first century AD, suggesting that the city disappeared
soon after.
As a city built on mud, Herakleion would have been vulnerable to
subsidence
during a big flood. "I'm not ruling out earthquakes,"
says Stanley. "But
flooding would be a strong contender."
Journal reference: Nature (vol 412, p 293)
© Copyright Reed Business Information Ltd.
==========
(3) WHO WILL SAVE US FROM DESTRUCTION? NEW TASK FORCE TO ASSESS
EVERY KNOWN
AND UNKNOWN (AND UNKNOWN UNKNOWN) HAZARD, DANGER, THREAT AND
POTENTIAL RISK
From Daily Telegraph, 18 July 2001
http://www.telegraph.co.uk/et?ac=003864436460684&rtmo=Qep30LHR&atmo=rrrrrrrq&pg=/et/01/7/19/ecfdoom19.html
Who will save us from destruction?
Killer plagues and asteroids used to be stuff of science fiction
- not any
more. The Government is almost on guard, reports Roger Highfield
PREPARE to be afraid, very afraid. The Government has set up a
special unit
to find out when the next horseman of the apocalypse will gallop
through the
neighbourhood.
Killer asteroids, doomsday plagues and a morbid fear of something
nasty
lurking in the lab were once the sole preserve of the feverish
minds of
science fiction writers. In the past few days, however, the
Government has
announced that it will turn to sci-fi in a big way to anticipate
catastrophes.
This sci-fi preoccupation started subtly some years ago, with the
Foresight
exercise, in which experts conducted crystal-ball-gazing studies
to shape
national research priorities. Predictions have ranged from
wallpaper that
changes colour at the flick of a switch and voice-controlled
kettles to the
ability to catch murderers by reading the fading memories of
their victims.
Meanwhile, science fiction - in the guise of theoretical risks -
began to
shape policy. British blood products were banned because of fears
- rather
than epidemiological evidence - that they transmit the BSE/vCJD
agent. The
introduction of GM food and crops was slowed despite the lack of
hard data
on deleterious effects. Computer models of global climate
informed
environmental policy despite our imperfect understanding of the
Earth's
complex weather system.
Although the science was speculative, it was at least plausible,
whether
based on test tube studies of the BSE agent, experiments on
pollen
distribution or our ability to model past climate change. But now
there are
calls for policy makers to go beyond established science and,
last week, the
Government responded to this challenge.
One of those pushing for change is Prof Robin Grove-White of
Lancaster's
Institute for Environment, Philosophy and Public Policy, who
believes the
public will only feel safe when the Government looks into
unanticipated
consequences, "unknown unknowns". This seems to go
beyond hard science
fiction - efforts to extrapolate from understood phenomena - to
science
fantasies about unknown phenomena.
What does he mean, exactly? Prof Grove-White cites examples where
"unknown
unknowns" have wrongfooted science: the BSE-CJD saga and a
succession of
earlier environmental issues such as DDT, CFCs, fossil fuels,
climate
change, the ozone layer, nuclear power and the effects of
low-level
radiation.
"The best science of the day failed to anticipate deeply
important
consequential effects, in advance of society's initial commitment
to a
specific technology or scientific practice," Prof
Grove-White told a recent
meeting at Gresham College, London.
Public fear of "unknown unknowns" is motivated by the
loss of confidence in
institutionalised politics and top-down scientific
"expert" assessment, he
said. This reflects more deep, diffuse and analytically elusive
concerns
than the simple cause-effect relationships - important though
these
undoubtedly are - upon which official risk assessments focus.
The problem is that unanticipated consequences, "unknown
unknowns," and
"surprises" lurk beyond the scope of questions raised
by scientists, Prof
Grove-White said. Scientists "tend to identify uncertainty
with deficiencies
of knowledge within known and specifiable parameters, rather than
with the
more chronic conditions of inevitable ignorance and lack of
capacity to
imagine future eventualities that may arise with a given
technology."
Prof Grove-White asked one advisory scientist if it is reasonable
to fret
over "unknown unknowns" in the case of GM plants. Which
unknowns? was the
reply. "That's precisely the point. Possibly they could be
surprises arising
from unforeseen synergistic effects, or from unanticipated social
interventions. All people have to go on is analogous historical
experience
with other technologies."
He asked the scientist if it would be a good idea to add warnings
about
"unknown unknowns" to the advice you're giving
Ministers? "No, as
scientists, we have to be specific," said the adviser.
"We can't proceed on
the basis of imaginings from some fevered brow."
Perhaps we can. Last week, the Government announced a new unit
that takes
science fantasy seriously, or at least as seriously as it can
without
introducing absurd measures, such as equipping the population
with hard
hats, lead aprons and biohazard suits. The Civil Contingencies
Secretariat
will "scan the horizon for emerging destructive
challenges," said the
Cabinet Office, explaining how 75 emergency planners have been
drafted in
from the Home Office.
Ironically, the same day that these details emerged, a glorious
example of
the havoc that can be caused by "unknown unknowns" was
unfolding in
Government. The department where this was taking place? The Home
Office,
donor of all those crisis experts.
The Home Office is introducing a £2.5 billion communication
system, known as
Airwave, which relies on a frequency that should be avoided,
according to a
report, because it may cause changes to brain tissue.
Airwave, a collaboration between BT and the police, is being
tested by
Lancashire police and will eventually become a national, digital
mobile
radio communications service for all emergency services by 2005.
It will
boost the speed and security of communication.
Airwave handsets use the European Tetra (Terrestrial Trunk Radio
System)
standard, which enable up to four users to access a single radio
channel
simultaneously. Their transmissions are confined to
"bursts" at the rate of
17.65 times per second (Hz).
But a report commissioned by the Department of Health, under the
chairmanship of Prof Sir William Stewart, former Government Chief
Scientist
and architect of Foresight, found that possible effects of
frequencies at or
near 16Hz included the release of calcium from brain tissue.
Neurons are
sensitive to calcium, which carries out signalling, regulates
secretions and
other tasks. Although the Stewart report found no consequences
for health,
let alone a plausible mechanism by which these frequencies could
affect
brain tissue, the use of that frequency should be avoided, it
concluded in
May 2000.
Almost a year later the Home Office announced that experts had
examined
Airwave and found "no obvious health risks". The
Government said Airwave
would go ahead on the proposed timetable. After all, the new
phones comply
with guidelines produced by the National Radiological Protection
Board.
Whitehall meetings last week involving scientists, police
representatives
and government officials reveal this unknown hazard still
troubles the
police and the new ministerial team at the Home Office. A
ministry spokesman
admitted that additional research is necessary because concerns
"continue to
be expressed".
The problem is that current safety guidelines are designed to
avoid heating
effects in the body while the outstanding concerns focus on
non-thermal
effects - such as calcium release - which have not yet been
resolved. Cancer
is probably not a worry, but what if this causes subtle effects
on memory
and concentration in the police and other emergency services?
A new report is due from the NRPB Advisory Group on Non-Ionising
Radiation.
The Defence Evaluation Research Agency and the neuroscientist
Prof Colin
Blakemore of Oxford University, who wrote the relevant section of
the
Stewart report, have also submitted studies.
But these review existing literature and are unlikely to probe
the unknown
consequences of the calcium effect. One study that will dig
deeper into the
effect of 17Hz radiation will not be finished until next year.
The introduction of Airwave "seems so obviously to
contravene a
recommendation of Stewart, albeit one hedged with
qualifications," said one
expert who attended a crisis meeting last week, adding that there
was a
failure in joined-up government.
Most troubling of all, the Airwave safety studies were only
commissioned
earlier this year. If the work had been under way when Stewart
was
published, these issues may have been resolved. Few experts
expect Airwave
to be any riskier than conventional mobile phones. But until more
work is
done, they can't be sure.
Sir William, who is also President of the Royal Society of
Edinburgh, is
disappointed by the delay, caused in part because his committee
was kept in
the dark about Airwave. "All the information that was
available was not
forthcoming despite having government and NRPB observers on the
committee,"
said Sir William, whose precautionary approach has been widely
welcomed.
Members of the NRPB who sat on his committee should have been
more
forthcoming about Airwave's 17Hz frequency. "They never said
anything about
it," he said. Dr John Stather, deputy director of the NRPB
and Stewart
committee secretary, commented: "The operators of Tetra were
invited to give
evidence to the Expert Group but chose not to.".
The Tetra specificationss were in fact laid out in Paragraph 4.19
of the
Stewart report, an anodyne statement with no discussion of the
implications.
But there was no hint of those "unknown unknowns" that
may ambush orthodox
science.
The Government's new disaster team should take note. This is the
second
major failure in marshalling scientific advice in the past year
(following
delays in modelling the foot and mouth epidemic) and shows that,
despite
spending almost £30 million on the BSE report, Whitehall has yet
to learn
the lessons of mad cow disease.
Doomsday scenarios - awaiting the worst
Scientists may not be able to predict the 'unknown unknowns', but
Mark
Peplow discovered that some disasters could be lurking just
around the
corner
John Oxford is Professor of Virology at St Bartholomew's and the
Royal
London School of Medicine:
"A global influenza epidemic is guaranteed. The
million-dollar questions are
when and where. I feel we ought to build up a stock of anti-flu
drugs,
possibly five million doses."
David Smith is Professor of Environmental Science at the
University of
Coventry:
"My immediate concern is with rising sea levels, and
increase in storminess,
along the British coastline. This has had severe effects on
coastal
communities, and it's something the Government needs to focus
on."
Professor Mark Bailey, Director of the Armagh Observatory:
"It is now generally accepted that kilometre-size comets and
asteroids run
into the Earth roughly once per 100,000 years and that such a
collision
would result in a global catastrophe, resulting in the deaths of
billions of
people worldwide, more than 10 million for the UK alone."
Chandra Wickramasinghe is Professor of Applied Mathematics and
Astronomy at
Cardiff University of Wales:
"I believe that living material was introduced to the Earth
by comets
billions of years ago, and this arrival has not stopped. There is
about 100
tonnes of comet debris introduced into the Earth's upper
atmosphere every
day, a significant proportion of which is organic matter. The
time is right
for the government to consider that material capable of affecting
human
biology is being brought to Earth from space."
Dr Hazel Rymer, Earth Sciences, Open University:
"The eruption of the Icelandic volcano Laki in 1783 released
toxic gasses
that killed most of the island's sheep - this led to the death of
a quarter
of Iceland's population. If it happened again, poison gasses
could drift
over the UK, causing acid rain that would seriously affect crops
for years
to come."
Copyright 2001, Daily Telegraph
===========
(4) TIME TO DEMOTE PLUTO? MAYBE
From The Columbo Dispatch, 15 July 2001
http://www.dispatch.com/news/news01/july01/768080.html
Tom Burns
For The Dispatch
The recent discovery of yet another Plutolike icy body at the
edge of the
solar system will surely reignite the controversy over what
constitutes a
planet. Do we kick Pluto out of the planetary pantheon because it
has
dozens, maybe hundreds, of icy brethren?
If we decide to reclassify Pluto, it won't be the first time that
a "planet"
was demoted to a "minor planet." In fact, the problem
stretches back 200
years to the discovery of Ceres.
Twenty years earlier, in 1781, William Herschel had discovered
the first
planet since prehistoric times when he accidentally spied Uranus.
There was no question about Uranus' planetary status. It was
clearly large
enough, and its orbit matched those of other planets. In fact,
Uranus'
position in the solar system seemed to verify a very odd theory
about the
planets.
Bode's Law, as it was called, seemed to predict the distances of
the planets
from the sun in numerical ratios. As stated by German astronomer
Johann Bode
in 1772, it goes like this:
Mercury, the first planet, is defined at a distance of 4 units
from the sun.
Venus, the next planet, is 3 more units away. The distance to
Earth, the
third planet, can be gotten by doubling the 3 (i.e., 4+6). The
distance to
Mars is determined by doubling the 6 (4+12). The next planet
should be at
4+24 units, but none existed there, at least as far as
astronomers knew in
1772. However, doubling the 24 (4+48) produced the distance to
Jupiter.
Doubling the 48 (4+96) produced the distance to Saturn.
Most astronomers considered Bode's Law a coincidence until
Herschel
discovered Uranus, which turned out to be right where Bode said
it would be.
Still, that missing planet (at 4+24) between Mars and Jupiter was
a fly in
the mathematical unguent. A frenzied search began for it.
However, it was
discovered purely by accident.
On Jan. 1, 1801, Sicilian monk Giuseppe Piazzi was making routine
observations of stars to plot their exact positions. Imagine his
surprise
when one of the stars appeared to move slowly against the rest.
Piazzi's
observations and the subsequent mathematical work of Carl Gauss
placed the
new object, called Ceres, precisely in the Bodean gap between
Mars and
Jupiter.
Piazzi had discovered a planet -- maybe. But Ceres was obviously
a tiny
thing -- 1,000 times fainter than Jupiter or Mars, the planets
that bracket
it. In fact, modern measurements indicate that it is a mere 579
miles wide,
just over one- quarter the diameter of Earth's moon. Also, in
1802, just a
year after Piazzi's discovery, Wilhelm Olbers discovered another
"planet,''
Pallas, in the Bodean gap. With the discovery of Juno in 1804 and
Vesta in
1807, Ceres' planetary status began to fade.
We now know of at least 10,000 "minor planets" or
asteroids orbiting the
sun. Most of them travel in the gap between Mars and Jupiter,
called the
asteroid belt. Small hunks of rock like these probably clumped
together by
their mutual gravity to form the rocky planets in the first
place. The
asteroids in the belt could not form a planet because of the
heavy-duty
gravity of Jupiter, which stirred them up.
And, by the way, the discovery of Neptune invalidated Bode's Law.
Even so, it bodes well to observe Ceres this year, the 200th
anniversary of
its discovery. A good pair of binoculars or small telescope will
show it
over the next few days just under the star Zeta in the
constellation
Sagittarius as a faint point of light. Check out the star map for
its exact
location.
Tom Burns directs Ohio Wesleyan University's Perkins Observatory
in
Delaware.
tlburns@cc.owu.edu
============
(5) INTERPLANETARY INTERNET IN THE WORKS
From CNN, 18 July 2001
http://europe.cnn.com/2001/TECH/internet/07/18/nasa.tech.advances.idg/index.html
By Gary H. Anthes
(IDG) -- The mining of asteroids, space-based hotels,
zero-gravity
manufacturing and medicine -- they're all part of the future
commercialization of space, according to a joint government and
industry
group that's developing the InterPlaNetary (IPN) Internet.
Starting this year, with NASA funding, the IPN will roll out in
pieces over
the next several decades to support communications among
spaceships, robots
and manned and unmanned outposts in the solar system.
"It's conceivable that the IPN could go like its terrestrial
counterpart,
starting out as a network supporting scientific research and
eventually
evolving into something of commercial interest," says Vinton
Cerf, senior
vice president of Internet architecture and technology at
WorldCom Inc.
Cerf co-invented TCP/IP in 1973 and is often called a
"father of the
Internet." He got the idea for an interplanetary extension
of the Internet
in 1997 and is now working with engineers at NASA's Jet
Propulsion
Laboratory (JPL) in Pasadena, Calif., to make it real.
"I started thinking about the past 25 years as the Internet
evolved, and I
thought, 'Gee, what should we be doing now so that in another 25
years, we
are ready for whatever's coming?' " Cerf explained.
The protocols, software and hardware developed for the IPN will
benefit
terrestrial internet users, especially in mobile applications,
Cerf says.
Protocols like TCP are unattractive for use in space because
they're
"chatty" -- they depend on near-real-time exchanges
between communicating
parties. But a message can take 40 minutes to travel between Mars
and Earth.
The large distances also limit bandwidth and introduce high error
rates.
"Size, weight and, most of all, power are supreme challenges
for space-based
communication systems, as they are for ground-based mobile
systems," said
the NASA-led IPN Research Group in a paper published in May.
Cerf says the IPN will be a "network of internets," in
which ordinary
internets are interconnected by a store-and-forward
"overlay" network that
forms a backbone across interplanetary space. Each internet's
protocols will
be terminated at its local gateway, and a new "long-haul
transport" protocol
will communicate between gateways. A new, end-to-end
"bundle" protocol will
operate above the transport layer to carry information from a
gateway on
Earth to one on Mars, for example.
Bundling is intended to eliminate the chattiness of local
protocols. For
example, a file-transfer request bundle might contain the user's
password,
the location of the file to retrieve and the address to which it
is to be
delivered.
These concepts may have applications on Earth as the terrestrial
Internet
becomes increasingly Balkanized, says Scott Burleigh, a senior
software
engineer at the JPL.
Firewalls and network address translation boxes that sit between
the
Internet and corporate intranets, along with the proliferation of
intermittently connected mobile devices, are introducing some of
the
challenges of communicating in space, he says.
Copyright 2001, CNN
============
(6) EARTHQUAKES REVEAL DIAMONDS' ORIGINS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
College of Liberal Arts & Sciences
Arizona State University
Tempe, Arizona
Danika Painter
Contact:
James Hathaway, (480) 965-6375, Hathaway@asu.edu
July 13, 2001
Earthquakes Reveal Diamonds' Origins
Jewel aficionados may soon be praying for an earthquake.
The seismic rumblings could provide key clues about where miners
should look
for diamonds, according to recent research. Matt Fouch, assistant
professor
of geological sciences at ASU, studies vibrations caused by
earthquakes to
visualize the earth at depths of hundreds of kilometers, where
diamonds are
formed. His maps of the earth below South Africa provide new
information
about Earth's structure in regions where many diamonds are found.
In the July 1, 2001 issue of Geophysical Research Letters, Fouch
and his
coauthors, David James, John VanDecar (both of the Department of
Terrestrial
Magnetism, Carnegie Institution of Washington), and Suzan van der
Lee (of
the Institute of Geophysics, Zürich, Switzerland), show that
some of
southern Africa's most profitable diamond mines are located near
areas where
the earth is exceptionally stable and cool up to 250 kilometers
below the
surface. The paper will be published in a special section of the
journal,
with seven other studies on geochemistry, composition, and rock
dating of
southern Africa.
Many diamonds come from regions, called cratons, that are some of
the most
geologically stable places in the world. Two cratons, the
Kaapvaal and
Zimbabwe cratons, covering an area roughly the size of the nation
of South
Africa, are the source of most of southern Africa's diamonds.
"The region we're studying in southern Africa is over 3
billion years old,
and in some places it's even 3.6 billion years old," says
Fouch. Geologists
think diamonds develop up to several hundred kilometers deep
within these
ancient cratons and are then driven straight up to the surface.
Miners scout the best places to dig for gems by looking for
diamonds that
have made their way to the surface. Other techniques, such as
drilling for
samples deeper in the rock or studying anomalies in the
gravitational or
magnetic properties of the earth in the area, increase the
chances of
finding diamonds. But none of these approaches guarantee success.
"If people knew exactly how it worked all the time, then
we'd have a lot
more diamond mines," Fouch jokes. "Nearly all diamonds
come from cratons,
but not all cratons contain diamonds. So the question is, why do
some
cratons produce diamonds and others don't? Another question is,
why do some
of those areas have diamonds that are commercially profitable,
and others
don't? Some regions have diamonds, but they're just too chewed up
to be gem
quality."
Fouch and his colleagues think they may have found part of the
answer deep
in the earth's mantle -- the layer of rock that extends several
hundred
kilometers beneath the crust. By imaging the earth at these
depths, they
looked at the very source of diamonds, rather than waiting for
them to
travel to the surface. Fouch created three-dimensional images of
deep layers
of the earth by using an array of 82 seismometers, sensors that
detect
vibrations caused by earthquakes from all around the world. The
seismometers, placed at roughly 100-kilometer intervals across
South Africa,
Zimbabwe and Botswana, recorded data from more than 200
earthquakes
occurring over a two-year period, mainly from the Himalayan and
Andean
mountain ranges. They used seismic tomography, a technique very
similar to
CAT scans in medical imaging, to produce the images.
"As people, we never want earthquakes to happen, but as
seismologists we
know they are an inevitability. So our job is to use them in the
most
productive way possible," says Fouch. "Every time an
earthquake happens,
it's like shining a flashlight on a particular part of the earth.
The
seismic waves from each earthquake bounce off of different layers
of the
earth and illuminate different internal features."
The speed and angle of earthquake waves' motion depends on what
kind of
material they travel through. For example, the rippling caused by
dropping a
pebble in a bowl of water will move differently than in water
containing ice
cubes or in a bowl of jelly. By analyzing the timing and angle of
the
vibrations' spread past the seismometers, Fouch and coworkers
mapped the
physical properties of the earth below.
They found that the mantle directly below the most productive
diamond mines
looks distinctly different than in the surrounding areas. In
diamond-producing areas, the mantle is "seismically
fast," meaning that it
propagates earthquake vibrations quickly because the mantle rock
may be
cooler or chemically different from the surrounding areas.
"There are a few distinct pockets of the faster seismic
velocities," Fouch
explains. "One of these regions is beneath the Kaapvaal
craton in South
Africa, and one -- a little more diffuse -- is beneath the
Zimbabwe craton.
... Most of the gem-quality diamond mines in southern Africa lie
very close
to these regions." By looking for similarly cold,
seismically fast parts of
the mantle, diamond miners may be able to identify new promising
areas for
mining. Industry collaborators in southern Africa are very
interested in
Fouch's research, and some even allowed the seismologists to
install
seismometers on their property.
"This is certainly a technique that could be used in
conjunction with other
methods to possibly determine whether a region might be more
prone to having
diamonds," Fouch says.
============================
* LETTERS TO THE MODERATOR *
============================
(7) SUPERVOLCANOES
From Hermann Burchard <burchar@mail.math.okstate.edu>
Dear Benny,
here is an item from BBC dated 3rd February 2000 that may already
be
familiar to CCNet:
http://www.bbc.co.uk/science/horizon/supervolcanoes_script.shtml
It apppears identical to a spot on DISCOVERY last week.
Yellowstone is
mentioned, which has been linked to a cosmogenic impact in SE
Oregon at
about 19 Ma. Apparently it's about to blow up again, as it has
been doing
intermittently (every few 100 K years). Also mentioned is Toba,
Sumatra
which blew 75 Ka. I was wondering if anything is known about
possible
impact-relations of Toba. At more than 30 miles it seems rather
large for an
ordinary volcanic caldera. Toba nearly caused our own ancestors
to become
extinct at the height of the last glaciation, according to BBC.
Regards,
Hermann
=============
(8) TUNGUSKA EXPEDITION
From Andrei Ol'khovatov <olkhovatov@mtu-net.ru>
Dear Dr.Peiser,
In CCNet of July 16 there was a post re: "ANOTHER SCIENTIFIC
EXPEDITION TO
TUNGUSKA METEORITE FALL SITE," posted by Ron Baalke and
citing PRAVDA
newspaper.
Unfortunately, the info about the expedition is a little bit
exaggerated. It
is not a big expedition. As far as I know, the expedition
consists of about
8 persons in total. Some of them participated in the Krasnoyarsk
part of the
TUNGUSKA 2001 International Conference, but failed to buy tickets
for the
flight to Vanavara (near the Tunguska epicenter), so they were
not able to
join the main group going to Tunguska, and had to go separetely.
The main
group of TUNGUSKA 2001 expedition of 10 persons made a short trip
to the
epicenter to take samples and making TV-documentaries. More info
on the
conference www.geocities.com/olkhov/conf01.htm.
As far as I know, at least
one more reader of CCNet took part in the conference and in the
trip, so
maybe he will share his impressions with others.
Sincerely,
Andrei Ol'khovatov
Russia, Moscow
=============
* ABSTRACTS *
=============
(9) PLANETARY DEFENSE: DIRECT HIGH-SPEED INTERCEPTION
Ulybyshev Y: Direct high-speed interception: Analytic solutions,
qualitative
analysis, and applications. JOURNAL OF SPACECRAFT AND ROCKETS 38
(3):
351-359 MAY-JUN 2001
Trajectories for high-speed interception in a thin spherical
shell of an
inverse-square central gravity field are considered. The
solutions are
obtained for the problem of exoatmospheric flight, open time
intercept of a
nonmaneuvering target in an orbit during free-flight phase. The
fixed-fuel
interceptor is assumed to have the capability of generating fixed
magnitude
thrust or a specific impulsive velocity change. A closed-form
solution for
the control law is derived. The thrust direction is a linear
function of the
relative states between the interceptor and target and a
nonlinear function
of the transfer time. This transfer time is obtained as an
analytic solution
to a quadratic equation. First- and second-order methods are
developed. A
qualitative analysis and a descriptive geometric interpretation
of a space
interception are considered. The results show that the optimal
guidance law
for the boost phase of an interceptor is the well-known constant
bearing
course relative to the target. Descriptive existence conditions
of
trajectories for a fixed-fuel interceptor are derived and a
computation
method to determine the reachable domain, that is, the boundary
set of
initial positions of the interceptor and target, is developed.
Numerical
examples of an asteroid interception and satellite interception
are
presented. KeyWords Plus: EARTH, ASTEROIDS
Addresses:
Ulybyshev Y, Rocket Space Corp Energia, Space Ballist Dept,
Korolev 141070,
Russia
Rocket Space Corp Energia, Space Ballist Dept, Korolev 141070,
Russia
Copyright © 2001 Institute for Scientific Information
============
(10) WOBBLING ASTEROIDS AND COMETS
Planetary and Space Science, Volume 49, Issue 9, August 2001,
Pages 937-955
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6T-43GH08G-5&_us
er=777686&_coverDate=08%2F31%2F2001&_rdoc=5&_fmt=summary&_orig=browse&_srch=
%23toc%235823%232001%23999509990%23255461!&_cdi=5823&_sort=d&_acct=C00004303
1&_version=1&_urlVersion=0&_userid=777686&md5=c66ff65d5d32150e5a3594696f3ad1
e6
Relaxation of wobbling asteroids and comets - theoretical
problems,
perspectives of experimental observation
Michael Efroimsky [efroimsk@fas.harvard.edu], Department of
Physics, Harvard
University, Cambridge, MA 02138, USA
Received 1 September 2000; revised 5 April 2001; accepted 8 May
2001
Available online 12 July 2001.
Abstract
A body dissipates energy when it freely rotates about any axis
different
from principal. This entails relaxation, i.e., decrease of the
rotational
energy, with the angular momentum preserved. The spin about the
major-inertia axis corresponds to the minimal kinetic energy, for
a fixed
angular momentum. Thence one may expect comets and asteroids (as
well as
spacecraft or cosmic-dust granules) to stay in this, so-called
principal,
state of rotation, unless they are forced out of this state by a
collision,
or a tidal interaction, or cometary jetting, or by whatever other
reason. As
is well known, comet P/Halley, asteroid 4179 Toutatis, and some
other small
bodies exhibit very complex rotational motions attributed to
these objects
being in non-principal states of spin. Most probably, the
asteroid and
cometary wobble is quite a generic phenomenon. The theory of
wobble with
internal dissipation has not been fully developed as yet. In this
article we
demonstrate that in some spin states the effectiveness of the
inelastic-dissipation process is several orders of magnitude
higher than
believed previously, and can be measured, by the presently
available
observational instruments, within approximately a year span. We
also show
that in some other spin states both the precession and
precession-relaxation
processes slow down considerably. (We call it near-separatrix
lingering
effect.) Such spin states may evolve so slowly that they can
mimic the
principal-rotation state.
Copyright © 2001 Elsevier Science Ltd. All rights reserved.
=============
(11) DIRECT SIMULATION OF METEOROIDS AND SPACE DEBRIS FLUX ON
LDEF
SPACECRAFT SURFACES
Jingqi Miao(a) [ j.miao@ukc.ac.uk
] and J. P. W. Stark(b)
From Planetary and Space Science, Volume 49, Issue 9 , August
2001, Pages
927-935
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6T-43GH08G-4&_us
er=777686&_coverDate=08%2F31%2F2001&_rdoc=4&_fmt=summary&_orig=browse&_srch=
%23toc%235823%232001%23999509990%23255461!&_cdi=5823&_sort=d&_acct=C00004303
1&_version=1&_urlVersion=0&_userid=777686&md5=4ff4ea18b4555b2a797c879028c62d
b4
a The School of Physics Science, University of Kent, Canterbury,
CT2 7NR, UK
b Engineering Department, Queen Mary and Westfield College,
University of
London, London E1 4NS, UK
Received 20 May 2000; revised 18 December 2000; accepted 3 April
2001
Available online 12 July 2001.
Abstract
The meteoroid flux on all faces of the long duration exposure
facility
(LDEF) is predicted by a direct simulation Monte Carlo (DSMC)
model, which
for the first time provides a self-consistent method to model the
collision
behaviour between both meteoroids and debris with oriented
spacecraft
surfaces. This new model includes the modified Divine's meteoroid
population, and Taylor's velocity distribution, to include the
effects of
planetary shielding and gravitational enhancement by the Earth.
Results
obtained when only meteroid impact is considered show good
agreement with
observed data and provide some correlation with previous models.
When the
space debris population is also included, the total particle flux
on
different faces of LDEF fits well with the observed measurements.
Information concerning Earth shielding, gravity capturing and
atmospheric
effects can be obtained by comparing the ratio of the number of
meteoroids
moving towards the Earth to the total number of the meteoroids,
obtained
from the DSMC model with measured data. Approximately 25% of the
meteoroids
flux is predicted as not returning into the interplanetary space
due to
these effects.
Copyright © 2001 Elsevier Science Ltd. All rights reserved.
===========
(12) THE EUCRITE/VESTA STORY
Drake MJ: The eucrite/Vesta story
METEORITICS & PLANETARY SCIENCE 36 (4): 501-513 APR 2001
Many lines of evidence indicate that meteorites are derived from
the
asteroid belt but, in general, identifying any meteorite class
with a
particular asteroid has been problematical. One exception is
asteroid 4
Vesta, where a strong case can be made that it is the ultimate
source of the
howardite-eucrite-diogenite (HED) family of basaltic achondrites.
Visible
and near-infrared reflectance spectra first suggested a
connection between
Vesta and the basaltic achondrites. Experimental petrology
demonstrated that
the eucrites (the relatively unaltered and unmixed basaltic
achondrites)
were the product of approximately a 10% melt. Studies of
siderophile element
partitioning suggested that this melt was the residue of an
asteroidal-scale
magma ocean. Mass balance considerations point to a parent body
that had its
surface excavated, but remains intact. Modem telescopic
spectroscopy has
identified kilometer-scale "Vestoids" between Vesta and
the 3:1 orbit-orbit
resonance with Jupiter. Dynamical simulations of impact into
Vesta
demonstrate the plausibility of ejecting relatively unshocked
material at
velocities consistent with these astronomical observations.
Hubble Space
Telescope images show a 460 km diameter impact basin at the south
pole of
Vesta. It seems that nature has provided multiple free sample
return
missions to a unique asteroid. Major challenges are to establish
the
geologic context of the HED meteorites on the surface of Vesta
and to
connect the remaining meteorites to specific asteroids.
Addresses:
Drake MJ, Univ Arizona, Lunar & Planetary Lab, Tucson, AZ
85721 USA
Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA
Copyright © 2001 Institute for Scientific Information
=============
(13) LOW ALBEDOS AMONG EXTINCT COMET CANDIDATES
Fernandez YR, Jewitt DC, Sheppard SS: LOW ALBEDOS AMONG EXTINCT
COMET
CANDIDATES
ASTROPHYSICAL JOURNAL 553 (2): L197-L200, Part 2 JUN 8 2001
We present radiometric effective radii and visual geometric
albedos for six
asteroids in comet-like orbits. Our sample has three of the four
known
retrograde asteroids (1999 LE31, 2000 DG(8), and 2000 HE46) and
three
objects [( 18916) 2000 OG(44), 2000 PG(3), and 2000 SB1] on
prograde but
highly elliptical orbits. These measurements more than double the
number of
known albedos for asteroids with a Tisserand invariant in the
cometary
regime. We find that all six of our objects, and nine of the 10
now known,
have albedos that are as low as those of active cometary nuclei,
which is
consistent with their supposed evolutionary connection to that
group. This
albedo distribution is distinct from that of the whole near-Earth
and
unusual asteroid population, and the strong correlation between
Tisserand
invariant and albedo suggests that there is a significant
cometary
contribution to this asteroid population.
Addresses:
Fernandez YR, Univ Hawaii, Inst Astron, 2680 Woodlawn Dr,
Honolulu, HI 96822
USA
Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA
Copyright © 2001 Institute for Scientific Information
============
* MEETINGS *
============
(14) FINAL ANNOUNCEMENT OF JAPANESE NEO WORKSHOP
From Syuzo Isobe <isobesz@cc.nao.ac.jp>
July 18, 2001
The 3rd Circular and the final request for registration.
An International Workshop
on
Collaboration and Coordination
Among NEO
Observers and Orbital Computers
Kurashiki City Art Museum
Kurashiki, Okayama, Japan
October 23 to 26, 2001
The Japan Spaceguad Association would like to hold a workshop
from October
23 through 26, 2001, at the Kurashiki City Art Museum (near the
Bisei
Spaceguard Center).
Following the workshop, we will inaugurate the Bisei Spaceguard
Center on
October 27.
Purpose of the Workshop:
In these years NEO matters have been discussed at different
occasions and
organizations. Number of NEO observers and orbital computers has
been
increasing and they have been producing excelent results.
However, it seems
that there were not much discussions on collaboration and
coordination among
them and some critical debates between those teams were brought.
Therefore,
the SOC intends to make this workshop to solve the problems or at
least to
start to its solution. Program of this workshop will be
arranged with some
introductory reports by NEO observers and orbital computers and
set aside
many hours for discussions.
SOC members: Syuzo Isobe (Co-Chair), Donald K. Yoemans
(Co-Chair),
Tom Morgan, Bob McMillan, Ted Bowell, Andrea Carusi,
Brian Marsden, Richard Binzel, Karri Muinonen, and
Mark Bailey
Program.
First day : October 23, Tuesday
17:00 -
21:00 Reception at Kurashiki City Art Museum (Light
meals are prepared)
Second day : October 24, Wednesday
1st Session Chairman Syuzo Isobe
9:30 -
9:40 Welcome address by LOC chairman M. Yoshikawa
9:40 -
9:50 Welcome address by Govener of Okayama Prefecture
M. Ishii
9:50 -
10:00 Welcome address by Assistant Executive Director
of NASDA T. Inada
Coffee Break
2nd Session
10:00 -
10:50 General remarks D. Yeomans
10:50 -
11:00 Short note S.
Isobe
NEO Detection Observation Teams
11:00 -
11:30 Space Watch
Team T. Gehrels
11:30 -
12:00 LONEOS team E. Bowell
12:00 -
12:30 NEAT team
E. Helin*
Lunch Break
3rd Session
14:00 -
14:30 LINEAR Team G. Stokes*
14:30 -
15:00 Catalina Team S. Larson
15:00 -
15:30 BSGC Team
M. Yoshikawa
Coffee Break
4th Session
NEO Followup Team
16:00 -
16:20
P. Pravec*
16:20 -
16:40
L. Ticha
16:40 -
16:50
M. Ticha
16:50 -
17:10
G. Tancredi*
17:10 -
17:30
D. Tholen
17:30 -
18:00 Discussion
Third day : October 25, Thursday
5th Session :
Organization Activity
8:30 -
8:45 Spaceguard Foundation A. Carusi
8:45 -
9:10 SGF Central
Node A. Boattini
9:10 -
9:35 NASA NEO Program Office D. Yeomans
9:35 -
10:00 IAU related
view H. Rickman
10:00 -
10:30 Discussion
Coffee break
6th Session
11:00 -
11:30 A review of space
mission J.Kawaguchi
11:30 -
12:00 Physical property of
NEO M. Greenberg
12:00 -
12:30 Discussion from the 2nd day
Lunch break
7th Session :
Impact Prediction Team
14:00 -
14:30 Minor Planet Center B.
Marsden
14:30 -
15:00 NASA P. Chodas
15:00 -
15:30 Finland K. Muinonen
15:30 -
16:00 Italy A. Milani*
Coffee break
8th Session
16:30 -
17:15 Discussion on the 3rd day
17:15 -
18:00 Discussion cooperative observation efforts
Fourth day : October 26, Friday
9th Session
Contribution by Space Debris Teams
8:30 -
8:55 NASA - US Air Force
teams J. Africano
8:55 -
9:20 ESA
team T. Schildneckt
9:20 -
9:45 NASDA team K.
Nonaka
9:45 -
10:00 NASDA software
development M. Kameyama
10th Session
10:30 -
12:00 Discussion on plan and schedule to optimize
international discovery and follow-up efforts
Lunch break
11th Session
13:30 -
15:00 Prepare final conclusion
15:00 -
15:10 The Final address and
announcement S. Isobe
18:30 -
21:00 Banquet at Okayama Sanko-So, Okayama city
All attendances and accompanying persons are invited
Fifth day : October 27, Saturday
9:00
Departure to the BSGC in front of Kurashiki City Art Museum
12:00
Arrive at the Bisei town. Lunch
13:00
Innagulation of the BSGC
15:00
Visit to BSGC
17:00
Return to Kurashiki (the first bus)
20:00
Return to Kurashiki (the second bus)
after supper and watching observations at BSGC
* Speaker may be changed.
Additionally to this program, we will hold two public lectures on
Sunday October 21 and Sunday
October 28.
Meeting location: Kurashiki city art museum
Address
2-6-1 Cyuou Kurashiki City Okayama-ken.
Telephone
81-86-425-6034
Facsimile
81-86-426-6036
How to reach:
Attendees and guests will
land at the Kansai International
airport, take a
super-express train with a name of Haruka to
Shin-Osaka
(about 50 minutes), followed
by a bullet train with a name of Hikari
(rapid) or Kodama (slow)
(Shin-Kansen) to Okayama (60 minutes),
and the a commuter train to
Kurashiki (10 minutes).
You should buy a ticket to
Kurashiki station and two supplement
tickets
for super-express and bullet
trains. These one way tickets cost
about 8,000 yen.
The other Attendees and
Guests will land at the Narita International
airport, take a super
express train with a name of Narita-Express
to Tokyo (about 60 minutes),
followed by a bullet train with a name
of Nozomi (much rapid but
expensive 3 hours 10 minutes) or Hikari
(rapid 4 hours) to Okayama,
and a commuter train to Kurashiki
(10 minutes). You should buy
a ticket to Kurashiki station and
supplement tickets for
super-express and bullet trains. These one way
tickets cost about 20,000
yen.
Accomodation:
There are a few hotels in
Kurashiki area. We blocked 30 single rooms
of Kurashiki Station hotel
and 30 single rooms of Toyoko Inn
Kurashiki
Minamiguchi until August 31.
You can request the other type hotel
room
to Isobe and LOC will try to
fit its request.
1 KURASHIKI STATION HOTEL
Address
2-8-1 Achi Kurashiki City Okayama-ken.
Telephone
81-86-425-2525
Facsimile
81-86-426-6702
Guest
room
all 111 rooms
Single
bed
\5,500 - \6,000
Twin
beds
\11,000 - \12,000
2 TOYOKO IN KURASHIKI MINAMIGUCHI
Address
2-10-20 Achi Kurashiki City Okayama-ken.
Telephone
81-86-430-1046
Facsimile
81-86-430-1046
Guest
room
all 154 rooms
Single bed (143 rooms) \5,800
Twin beds
A
\7,300
Twin beds
B
\7,800
Sight seeing:
There are several good sight
seeing areas not far from the Workshop
hall. We will give you
further informations in the next circular.
Weather and the other informations:
October is one of the best
season in Japan. Temperature is usualy
11 - 17 degree C. In the
evening, you may need an additional sweater.
There is some percent of
probability to be rainy as usual in Japan
and may be occasionally hit
by a typhoon. At the Bisei trip, you can
enjoy a beuariful maple.
Electricity is 100 V and 60
Hz.
Registration fee:
15,000 yen which covers
refreshment during meeting, one copy of
proceeding, and trip to the
Bisei Spaceguard Center.
Please send back following informations to the e-mail address of
Isobe,
by May 25, 2001.
Family Name:
First Name:
Institute:
Postal Address:
Tel. Number:
Fax. Number:
e-mail Address:
O I will attend the
workshop.
O I do not decide yet.
O I do not attend the
workshop.
O I am an invited
speaker.
O I would like to
present a paper.
O I will not present a
paper.
Title of paper:
_________________________________________________
Arrival date to
Kurashiki ___ October, 2001
Departure date from
Kurashiki ___ October, 2001
Which hotel will you ask LOC
reserve? 1 or 2
O Prepare your hotel room by
yourself.
O Request LOC to look for
the other hotel room.
Please write your request: _________________________________.
If you have any specific
request(s), please write below:
____________________________________________________________.
If you need further
informations on hotel in Tokyo or Osaka area,
please contact with Isobe.
Kurashiki City is in the Edo
period style (17 to 19 century).
Thank you for your coorporation.
==============
(15) FIRST ANNOUNCEMENT: THE INSPIRATION OF ASTRONOMICAL
PHENOMENA
From Rolf Sinclair <rolf@SANTAFE.EDU>
THE INSPIRATION OF ASTRONOMICAL PHENOMENA
-- FOURTH CONFERENCE --
Magdalen College, Oxford (UK) August 3-9, 2003
FIRST ANNOUNCEMENT
Dear Colleagues:
The International Executive Committee for the INSAP Conferences
wishes to
announce the fourth meeting in the series on "The
Inspiration of
Astronomical Phenomena" (INSAP IV). In this meeting
mankind's fascination
with the sky by day and by night will be explored. Such
fascination has been
a strong and often significant element in human life and culture.
The
conference will provide a meeting place for artists and scholars
from a
variety of disciplines (including Archaeology and Anthropology,
Art and Art
History, Classics, History and Prehistory, the Physical and
Social Sciences,
Mythology and Folklore, Philosophy, and Religion) to present and
discuss
their studies of the influences that astronomical phenomena have
had on
humanity.
The first three meetings (Castel Gandolfo, 1994; Malta, 1999;
Palermo, 2001)
successfully brought together, often for the first time, people
from just
such a range of disciplines to address topics of common interest.
Papers
from the first meeting were published in "Vistas in
Astronomy" (1995) and in
"Leonardo" (1996); those from the second will appear
shortly in book form,
"The Inspiration of Astronomical Phenomena: Edition
Malta"; those from the
third will appear in 2002 in a special issue of "Memoria
della Società
Astronomica Italiana". These papers (described on our
Website under each
INSAP Conference) give an idea of the range of subjects presented
at these
meetings. A similar publication is planned for the fourth
conference.
The next meeting will be held in Magdalen College, Oxford (UK),
starting
Sunday, 3 August 2003. Further information on INSAP IV and on the
earlier
conferences, together with an application form (on-or-after 1
September
2001) for the upcoming meeting, can be found on our Website
(http://ethel.as.arizona.edu/~white/insap)
or obtained from the undersigned.
Attendance will be by invitation from among those applying.
Applicants need
not present a paper or a poster: "observers" are
welcome, but must also
apply as space is limited. All presentations and discussions will
be in
English. As has been customary in the past, the Vatican and the
Steward
Observatories will be among the sponsors of the Fourth
Conference.
For further information, contact:
Dr. Valerie Shrimplin, University of Luton: Co-Chair, Local
Organizing
Committee (valerie.shrimplin@luton.ac.uk)
Mr. Nick Campion, Bath Spa University College: Co-Chair, Local
Organizing
Committee (ncampion@caol.demon.co.uk)
Professor David W. Pankenier, Lehigh University: Coordinating
Member,
International Executive Committee (david.pankenier@lehigh.edu)
Please circulate or post this announcement.
13/VII/2001
==================
(16) AND FINALLY: NO VOLCANOES, NO EARTHQUAKES, BUT LOTS OF
CLOUDS. BRITISH
ENVIRONMENT ON MARS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
[ http://www.nature.com/nsu/010719/010719-6.html
]
Monday, 16 July 2001
And now: the weather on Mars
The red planet is a lot more cloudy than we thought
By TOM CLARKE
Missions that landed on Mars revealed a still surface,
undisturbed by
volcanoes, earthquakes or landslides. The red planet's atmosphere
is nowhere
near so boring, say researchers who have been watching clouds,
winds and
dust storms racing around the planet for a full martian year [1].
Studying Mars' climate in the coming years should yield important
information about the transport of water and dust around the
planet, and
provide new insights into what climatic conditions were like
before Mars
became the barren globe it is today.
"The surface of Mars may be quiescent; the atmosphere
certainly is not,"
says John Pearl at NASA's Goddard Space Flight Center in
Greenbelt,
Maryland, who is analysing data from the Mars Global Surveyor
spacecraft,
which began orbiting Mars in 1997.
Clouds on Mars were first seen in detail in the 1970s by the
Viking Orbiter
spacecraft, "but no obvious general trends were
observed," says Francois
Forget, who studies the martian atmosphere at the University of
Paris,
France.
Mars Global Surveyor is equipped with an instrument that measures
how light
is reflected from the martian atmosphere, giving real-time data
on its
changes. "These are the first really quantitative
observations of clouds,"
says Forget.
Valleys filled with low-lying morning fog and high peaks shrouded
in mist
indicate local-scale variations -- or 'microclimates' -- in the
martian
environment. At night, the carbon dioxide and water that make up
martian
clouds seem to freeze out and fall to the ground. "This
tells us that
water-ice clouds may play a significant role in the
climate," says Forget.
Because Mars doesn't have any oceans -- which drive cloud
formation on Earth
-- researchers had expected the martian atmosphere to be
relatively easy to
understand.
"It's turning out to be very complex," says Pearl. His
team mapped a large
cloud belt around the middle latitudes of northern Mars; the
cloud stayed
put for the entire summer season, only to disappear in early
autumn. They
also watched as a winter dust storm banished clouds from the
southern
hemisphere.
Large-scale weather patterns like these are the key to
understanding
long-term patterns in martian climate, says Pearl. Their job now
is to start
to interpret their observations.
Other researchers will now incorporate Surveyor's weather
observations into
'global circulation models' of martian climate. As data
accumulates over the
next few years, these models should be able to predict martian
climate
patterns.
By running theses models backwards in time, says Pearl, it could
be possible
to see what the climate of Mars used to be like. This information
is crucial
for those studying the planet's recent past, when liquid water is
thought to
have flowed over its surface.
Real-time climate data from Surveyor may also be crucial to Mars
missions.
Dust storms, which are turning out to be common on Mars, can
interfere with
the 'aerobraking' manoeuvres that are used to get spacecraft into
orbits
around the planet. Knowing the size and position of a dust storm
can allow
spacecraft trajectories to be adjusted to avoid this problem,
says Pearl.
A few months ago, a giant dust storm began to form on Mars; now
at its peak,
the storm encircles the entire planet. It is the first time that
a major
dust storm has been followed from the start. Says Pearl:
"Our observations
would have made 19th-century astronomers drool."
The researchers are confident that the storm will have passed by
the time
NASA's Mars Odyssey mission arrives at the planet in October.
References
[1] Pearl,, J. C., Smith, M. D., Conrath, B. J., Bandfield, J. L.
&
Christensen, P. R.Observations of martian ice
clouds by the Mars Global
Surveyor Thermal Emission Spectrometer: The
first martian year. Journal
of Geophysical Research, 106, 12325 - 12338,
(2001).
© Nature News Service / Macmillan Magazines Ltd 2001
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