PLEASE NOTE:
*
CCNet, 27/2000 - 2 March 2000
-----------------------------
QUOTE OF THE DAY
"Colder winters and the extinction
of hundreds of species
including horses in Europe and plankton
in the Caribbean marked
the end of the Eocene, occurring
approximately 35 million years
ago. Oddly, Eocene summers remained hot.
Many scientists believe
an asteroid impact--with a signature
crater now buried under the
Chesapeake Bay in Virginia, U.S.A.--may
have caused the Eocene
extinctions and associated climate
change. But unlike the K-T
extinctions, the Eocene deaths are not
as extensive. Now,
according to a theory by former NASA
astronomer Dr. John A.
O'Keefe, of Garretson, S.D., we may have
to look elsewhere in
space for the Eocene killer. O'Keefe
[...] believes the Chesapeake
Bay impact did not cause the Eocene
extinctions. Instead, he
theorizes, a temporary, Saturn-like ring
of micro or larger
tektites around the Earth may be to
blame. Such an unstable
ring--which might have lasted a million
years or more--could have
cast a shadow across the North and South
Hemispheres as the
seasons changed.
-- Louis
Varricchio on John OKeefes new theory
(1) WHAT CAUSED THE EOCENE EXTINCTIONS?
Louis Varricchio <varricch@aero.und.edu>
(2) MARTIAN METEORITES REVEAL CLUES TO PROCESSES IN
PLANET'S ATMOSPHERE
Andrew Yee <ayee@nova.astro.utoronto.ca>
(3) THE SCULPTURED SURFACE OF EROS
Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
(4) MPAPW2K CALL FOR PAPERS
Roy Tucker <tucker@noao.edu>
(5) AT LAST: RESEARCHERS TAKE COSMIC AGENTS OF CLIMATE CHANGE
INTO ACCOUNT
European Space Agency <sciweb@estec.esa.nl>
(6) INTERNATIONAL COMET EXPLORER
Larry Klaes <lklaes@bbn.com>
(7) JACK HILLS' TALK ON DAMAGE FROM IMPACTS OF COMETS &
ASTEROIDS
Rolf Sinclair <rolf@santafe.edu>
(7) LUNAR CONFUSION
juan zapata-arauco <juanwisdomquest@yahoo.com>
(8) SAD & BEAUTIFUL POEM
David H Levy <david@jarnac.org>
(9) A FOREST FROM THE PAST
Doug Keenan <Doug.Keenan@virgin.net>
(10) WHAT TERMINATED THE LAST ICE AGE?
Benny J Peiser <b.j.peiser@livjm.ac.uk>
(11) NASA'S MAIN SATURN V BOOK
Larry Klaes <lklaes@bbn.com>
(12) AND FINALLY: COSMIC VACUUM CLEANERS
John B Youles <john.youles@dial.pipex.com>
============
(1) WHAT CAUSED THE EOCENE EXTINCTIONS?
From Louis Varricchio <varricch@aero.und.edu>
From ENN Direct, 2 March 2000
http://www.enn.com/direct/displayrelease.asp?id=938
"WHAT CAUSED THE EOCENE EXTINCTIONS? Former NASA Scientist
Thinks a
Lunar Volcano May Have Formed a Saturn-Like Ring of Tektites
Around
Earth 35 Million Years Ago"
Wednesday, March 1, 2000
GARRETSON, S.D. -- At the dawn of the Eocene epoch, when
Metasequoia
trees towered in arctic latitudes and primitive horses thrived in
the
humid underbrush, summers were hot and winters were brief and
comfortably cool.
Colder winters and the extinction of hundreds of species
including
horses in Europe and plankton in the Caribbean marked the end of
the
Eocene, occurring approximately 35 million years ago. Oddly,
Eocene
summers remained hot. Many scientists believe an asteroid
impact--with
a signature crater now buried under the Chesapeake Bay in
Virginia,
U.S.A.--may have caused the Eocene extinctions and associated
climate
change. But unlike the K-T extinctions, the Eocene deaths are not
as
extensive.
Now, according to a theory by former NASA astronomer Dr. John A.
O'Keefe, of Garretson, S.D., we may have to look elsewhere in
space for
the Eocene killer.
O'Keefe, the maverick astronomer who discovered Earth's slight
pear-shape in 1958 (using U.S. Vanguard satellite data) and who
helped
establish Project Apollo's lunar geology program in the early
1960s (he
is credited with NASA's recruiting the late astrogeologist and
comet
discoverer Eugene Shoemaker), believes the Chesapeake Bay impact
did
not cause the Eocene extinctions. Instead, he theorizes, a
temporary,
Saturn-like ring of micro or larger tektites around the Earth may
be to
blame. Such an unstable ring--which might have lasted a million
years
or more--could have cast a shadow across the North and South
Hemispheres as the seasons changed.
The ex-NASA scientist, now an independent researcher, calculates
that
such a ring would have screened out nearly a third of the
sunshine
falling to Earth--about as much as a kitchen window screen.
Tektites are glassy stones found in so-called "strewn
fields"
worldwide; the stones range in size from the ultra small to large
lava-like chunks called 'Muong Nong' tektites. Tektites are
nearly free
of water and other volatiles.
Tektite strewn fields differ widely in age, but most tektites,
regardless of age, are meteorite-like and some show evidence of
atmospheric entry--a phenomenon called ablation. Eocene-age
tektites
found in North America appear to have fallen in a vast arc from
Massachusetts to Texas. They are not associated with the
Chesapeake
crater, O'Keefe notes.
"Conventional wisdom suggests that asteroids produce
tektites from
sedimentary rock on Earth," says O'Keefe. "I don't
believe this. Impact
craters, larger and smaller than Chesapeake Bay, can be found
that have
no tektites associated with them. Besides, the chemical
composition of
tektites resembles that of high-silica materials such as granite
or its
glassy equivalent, volcanic rhyolite, not sedimentary material.
The
origin of tektites by meteorite or comet impact on Earth cannot
be
squared with known physical principles of how natural glass
forms. They
don't resemble impact glass."
O'Keefe has demonstrated that tektites--ranging in color from
dark
green to black--differ significantly from other natural glasses
found
at impact sites. The subject of tektites is a complex one and
there's
no easy telling of how the various shapes form and cool, OKeefe
says.
A tektite, he notes, is largely free of impurities; the so-called
splashform tektites (shaped like teardrops and dumbbells) took
seconds
to cool in the vacuum of space while the larger, layered tektite
chunks
took many minutes to form and cool. Conversely, all natural
impact
glass forms within seconds of an impact and contains many
impurities;
thus tektites cannot be impact glasses, according to O'Keefe.
If tektites aren't formed by impact, as O'Keefe believes, then
where do
they come from?
"I believe tektites point to a non-impact phenomena,
probably a
non-terrestrial volcano. The closest logical source for tektites
is the
Moon," he says. O'Keefe believes that explosive, silicic
volcanic
eruptions on the Moon could blow molten blobs of glass--at lunar
escape
velocity--far into space. The Earth's gravity would eventually
capture
the material to form an O'Keefe ring.
OKeefe points to a tektite smoking gun from a
moon rock returned to
Earth in November 1969. He cites an extensive study of an Apollo
12
specimen (designated No. 12013 by NASA) which strongly suggests a
lunar
origin for at least one family of tektites. Analysis shows that
the
unusual Apollo moon rock is similar to Southeast Asian tektites
in major
chemical element composition.
Petrologist Darryl Futrell, a natural glass expert from Los
Angeles,
Calif., agrees with O'Keefe's interpretation of tektites.
"Tektites are
too water-free to be from the Earth plus they cannot have formed
by
impact," Futrell says. "It simply takes too long-many
hours or even
days--for tektite glass to lose its volatiles. The igneous
chemical
trends in tektites also points to a volcanic origin, not an
impact
origin."
So what happened to O'Keefe's hypothetical ring? "It would
have been
blown away by sunshine," he says. "In the frictionless
environment of
space that's enough to sweep away a ring in a million years or
so."
O'Keefe also suggests that button-like tektites found in
Australia and
Indonesia, and part of a vast strewn field of tektites stretching
from
China to Australia, may have formed a second, younger terrestrial
ring.
No known impact crater has ever been found associated with the
700,000-year-old Southeast Asian tektite strewn field.
For more information, contact:
Louis Varricchio
Science Correspondent
Vector Science News Service
802-777-2482
morbius@together.net
==================
(2) MARTIAN METEORITES REVEAL CLUES TO PROCESSES IN
PLANET'S ATMOSPHERE
From Andrew Yee <ayee@nova.astro.utoronto.ca>
University of California-San Diego
Media Contact: Kim McDonald, (858) 534-7572, kimmcdonald@ucsd.edu
March 1, 2000
MARTIAN METEORITES REVEAL CLUES TO PROCESSES IN PLANET'S
ATMOSPHERE
Detailed measurements of sulfur isotopes in five Martian
meteorites
have enabled researchers at the University of California, San
Diego
to determine that the abundant sulfur on the surface of Mars is
due
largely to chemical reactions in the Red Planet's atmosphere that
are
similar to those that occur in Earth's atmosphere.
Their conclusions, which are detailed in a paper in the March 2
issue
of Nature, also suggest that the variations in sulfur isotopes
found
on ALH84001, the Martian meteorite thought by some scientists to
contain evidence of ancient Martian life, are not due to
biological
processes.
Instead, the UCSD researchers say, the chemical processes that
produced the variations in sulfur isotopes on many of the bits of
rock that were blasted from the surface of Mars millions of years
ago
and eventually recovered on Earth appear to be purely inorganic
--
that is, non-biologic.
"On Earth, if you see a large variation in the sulfur
isotope ratio,
it generally, though not exclusively, means you've got a biogenic
input," said Mark H. Thiemens, professor of chemistry and
biochemistry and dean of the Division of Natural Sciences at
UCSD.
"Organisms are very good at separating isotopes and choosing
one over
the other. So when you see big changes in isotope ratios, it
often
means biochemistry."
On Earth, such changes are often produced by terrestrial bacteria
that derive their energy solely from the conversion of sulfur
compounds from one form to another. In so doing, they selectively
break the chemical bonds of the lighter isotopes of sulfur,
producing
large variations in the normal sulfur-isotope ratio.
In their laboratory, Thiemens and UCSD researchers James
Farquhar,
Joel Savarino and Terri L. Jackson sought to find out whether
some of
this sulfur may have been produced by organisms. They also
examined
the sulfur in the Martian meteorites to find clues to the
evolution
of the Martian atmosphere, a major puzzle for planetary
scientists.
"Sulfur and a number of other elements are involved in the
chemical
and physical cycling of elements between oceans, rocks, living
organisms and the atmosphere," said Farquhar, the principal
author of
the study. "We have shown that the sulfur-isotope ratios in
Martian
meteorites have a component that can only be explained by
atmospheric
chemical reactions. This provides new insights into the origin of
sulfur species found at the Viking and Pathfinder landing sites,
and
into sulfur mobility within the Martian surface."
"Mars is a nice case study, because it's relatively
simple,"
explained Thiemens. "There's not that much atmosphere, it's
photochemical, it couples directly to the surface and it's not
complicated by biology or an ocean. Sulfur is a major element and
it
has a number of isotopes, so it's a very nice probe to understand
an
entire planetary system."
The UCSD researchers' measurements of sulfur isotopes in reduced
and
oxidized phases, which were supported by the National Aeronautics
and
Space Administration, are the first from a group of Martian
meteorites, known as SNC meteorites. Only about a dozen of these
rare
meteorites have been recovered over the past two centuries.
Farquhar
and his colleagues examined samples of five meteorites in this
group,
including a 1.3 billion-old-year Martian rock that reputedly
killed a
dog when it fell to Earth in 1911 near Nakhla, Egypt and a
165-million-year-old chunk of the Red Planet that fell near
Shergotty, India in 1865.
The UCSD scientists said the isotopic variations in those
meteorites,
combined with what is known about the Martian atmosphere from the
Viking landers, are best accounted for by inorganic chemical
reactions in the atmosphere, not biological processes.
"When you put them all together to account for the data, it
fits,"
said Thiemens. "Biology can't accommodate what we see, but
the
photochemistry in the Martian atmosphere does."
The UCSD researchers will also present their results later this
month
at the Lunar and Planetary Science Conference, scheduled for
March
13-17 in Houston.
===============
(3) THE SCULPTURED SURFACE OF EROS
From Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
NEAR image of the day for 2000 Mar 1
http://near.jhuapl.edu/iod/20000301/index.html
NEAR takes several images mosaics of Eros daily for purposes of
navigating the spacecraft. The one shown here was taken February
29,
2000, from a range of 289 kilometers (180 miles). It shows
features as
small as 30 meters (100 feet) across. All of the mosaics show the
same
territory over and over, but changes in lighting plus the gradual
decrease in the spacecraft's range to the surface are both
constantly
bringing out new details.
The very oblique illumination in this mosaic is ideal for
bringing out
small landforms. Many parts of the asteroid have
"grooves," linear
troughs about 100 meters (330 feet) wide and several kilometers
long.
Similar features have also been observed on other asteroids such
as
Gaspra, and they are especially numerous on Mars' moon Phobos.
Their
origin isn't completely understood, but formation of the grooves
probably involves fracturing of the asteroid's subsurface in some
way.
--------------------------------------------------------
Built and managed by The Johns Hopkins University
Applied Physics Laboratory, Laurel, Maryland, NEAR was the first
spacecraft launched in NASA's Discovery Program of low-cost,
small-scale planetary missions. See the NEAR web page at
http://near.jhuapl.edu for
more details.
================
(4) MPAPW2K CALL FOR PAPERS
From Roy Tucker <tucker@noao.edu>
Ladies and Gentlemen of the asteroid community,
The 2000 Minor Planet Amateur/Professional Workshop will be held
from
the 15th to the 18th of June at Alfred University
(http://bitnik.com/mp/mpw2000/mpw2000.html).
If you wish to present
an oral or poster paper during this meeting, you are invited to
submit an abstract for consideration and scheduling to
"gpobs@azstarnet.com"
before April 15th. Highest priority will be
afforded to presentations relating to astrometry, photometry, and
instrumentation (hardware and software) supporting these types of
observations.
Thank you very much.
Roy Tucker
David DeGraff
Chairmen, MPAPW2K
===============
(5) AT LAST: RESEARCHERS TAKE COSMIC AGENTS OF CLIMATE CHANGE
INTO ACCOUNT
From the European Space Agency <sciweb@estec.esa.nl>
Discoveries about how the Sun may affect the Earth's climate will
be
discussed on the Spanish island of Tenerife, 25-30 September
2000.
The leading hypothesis in climate science is that most of the
warming
during the 20th Century was due to manmade gases, enhancing the
natural greenhouse effect that reduces heat loss into space.
Behind
the scenes, and especially among space scientists, there is
renewed
attention to natural changes in climate due to the Sun.
More at:
http://sci.esa.int/newsitem.cfm?TypeID=1&ContentID=9511&Storytype=12
====================
(6) INTERNATIONAL COMET EXPLORER
From Larry Klaes <lklaes@bbn.com>
http://www.washingtonpost.com/wp-srv/WPlate/2000-02/28/077l-022800-idx.html
To quote in part:
Back in 1985, planet Earth was getting ready for a rare encounter
with Halley's comet, which passes by every 76 years. It was due
in
September 1986 [Halley was already heading back out again by that
month], and Soviet, Japanese and European space missions had
already
been launched to soar out and study it up close in what was to be
man's first encounter with a comet.
To the dismay of the American space community, however, budget
cutters
had vetoed a $500 million U.S. mission.
At the time, Farquhar was in charge of an antiquated spacecraft
[named
ISEE-3] parked in a "halo orbit," where the
gravitational forces of the
sun and Earth held it virtually suspended so little fuel was
needed to
maintain its position. Its instruments had been studying
"solar wind."
Troubled by America's pending humiliation over Halley's comet,
the
Wizard of Orbits figured a way to yank this old spacecraft free
with a
few inexpensive bursts of its engines. Why not, he asked
colleagues,
redeploy it to beat the Rooskies and others to a comet? Halley's
would
be too far away, but Giacobini-Zinner would be in the
neighborhood half
a year earlier.
Some at NASA were upset with these Wild West tactics, but
Farquhar--
at one point designing the relevant trajectories from an
intensive-care
unit where he'd been parked after a heart attack--prevailed, with
spectacular results.
In September 1985, his old spaceship galloped through the tail of
Giacobini-Zinner, gathering valuable data as it went.
"A snappy demonstration of scientific and bureaucratic
derring-do,"
crooned a front-page Los Angeles Times story.
Reagan's letter of praise to Farquhar noted that not only was
this the
first close inspection of a comet, but "NASA estimates that
by diverting
the Explorer, as opposed to building a new spacecraft, you may
have saved
the nation as much as $200 million." [Almost as much as the
budget for
James Cameron's 1997 film Titanic! And isn't the USA all
the better
for it?]
To read more on ISEE-3, renamed ICE or the International Comet
Explorer, see this Web site:
http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/images/isee3_images.html
Larry
================
(7) JACK HILLS' TALK ON DAMAGE FROM IMPACTS OF COMETS &
ASTEROIDS
From Rolf Sinclair <rolf@santafe.edu>
University of Maryland at College Park
Department of Astronomy
Astronomy Colloquium
Series: Astronomy Colloquium
Date: Wednesday 8-March-00
Time: 16:00-17:00 (4:00-5:00 pm)
Location: CSS 2400
Speaker: Dr. Jack Hills (Los Alamos National Laboratory)
Title: "Damage from the Impacts of Comets and Asteroids with
Earth"
Comets and asteroids can cause severe damage on impact with
Earth.
Stony asteroids greater than 40 meters in diameter can cause
airblast
damage which rapidly increases with asteroid size. The airblast
from
a stony asteroid 200 meters in diameter can destroy an area the
size
of Connecticut. Asteroids larger than 200 meters in diameter
can
cause direct ground impact damage: craters, earthquakes, and
tsunami.
Tsunami is probably the greatest single danger from these
objects. An
asteroid the size of the KT impactor that destroyed the dinosaurs
65
million years ago would swamp all of Florida if it impacted in
the
midAtlantic. An asteroid of this size hitting anywhere in the
Pacific
would destroy Tokyo and much of the surrounding flat area. Large
asteroids would also cause worldwide darkness that could persist
for
months, which is likely to cause mass starvation in developing
countries. Such impacts can be prevented if preparation is made
early
enough.
------------------------------------------------------------------------
Colloquia are usually preceded by coffee and followed by an
informal
reception (both in room CSS 0254). Anyone interested in having
lunch
or talking with the speaker should contact either of the
colloquium
coordinators (see below). The hour immediately after lunch will
normally be reserved for the speaker to talk to graduate
students.
Students are urged to contact the coordinator to arrange this.
Parking for visitors is available in the Parking Garage 2 facing
the
Computer and Space Sciences Building.
Special accommodations for individuals with disabilities can be
made
by calling (301) 405-3001. It would be appreciated if we are
notified
at least one week in advance.
------------------------------------------------------------------------
Email: coll-request@astro.umd.edu
Phone: Cole Miller (301) 405-1037
=============================
* LETTERS TO THE MODERATOR *
=============================
(7) LUNAR CONFUSION
From juan zapata-arauco <juanwisdomquest@yahoo.com>
Dear Benny:
Thanks to the CCNet members that did a clear explanation about
the Moon
orbital inclination. I've lived all my life on a mistaken
conception
about this elementary fact of astronomy.
Juan
============
(8) SAD & BEAUTIFUL POEM
From David H Levy <david@jarnac.org>
Thank you for that beautiful poem Benny.
David
=================
(9) A FOREST FROM THE PAST
From Doug Keenan <Doug.Keenan@virgin.net>
Benny,
It is very unlikely that the Michigan forest reported by ABC News
was destroyed by a rapid change in climate. Rather, there was
most likely a nearby natural dam that burst, resulting in a
flood.
This basic idea has been proposed by many researchers to explain
other rapid floods that occurred, asynchronously, after the end
of the ice ages. The flood waters originated from melting
glaciers.
Cheers,
Doug Keenan
http://freespace.virgin.net/doug.keenan
=============
(10) WHAT TERMINATED THE LAST ICE AGE?
From Benny J Peiser <b.j.peiser@livjm.ac.uk>
Dear Doug,
The most interesting item in the report by ABC News [see:
http://abcnews.go.com/sections/science/DyeHard/dyehard.html]
is the
reported lack of dendrochronological evidence that would suggest
a
*gradual* climatic upturn at the end of the Pleistocene. It's not
so
much how the ancient forest in question became inundated, but
rather
what the actual acceleration was with which the Ice Age
terminated and
fairly abrupt global warming set in. These latest findings add to
recent studies that showed the Pleistocene-Holocene transition to
have
transpired within a brief span of 50 years or so, thus casting
more
doubt on the traditional Milankovitch-theory of gradual climate
chance.
The question thus arises as to the actual mechanism for such
sudden and
extreme climatic changes. Can I remind interested readers that
only
recently, Sir Fred Hoyle and Chandra Wickramasinghe presented
their
oceanic-impact cum greenhouse effect theory in their CCNet-Essay
"ON
THE CAUSE OF ICE-AGES", [see
http://abob.libs.uga.edu/bobk/ccc/ce120799.html].
Admittedly, Fred and
Chandras hypothesis is still rather speculative. But it is,
to my
knowledge, the only scientific attempt to date to address the
puzzle of
abrupt global warming at the end of the last Ice Age.
=================
(11) NASA'S MAIN SATURN V BOOK
From Larry Klaes <lklaes@bbn.com>
Hi Benny,
CCNet readers who want to know more about the Saturn 5 rocket
should
order this NASA book:
http://www.hq.nasa.gov/office/pao/History/series95.html
Bilstein, Roger E. Stages to Saturn: A Technological History of
the
Apollo/Saturn Launch Vehicles. NASA SP-4206, 1980 and 1996.
This paperback book is also available by calling the Government
Printing Office at 202-512-1800 and ordering Stock Number
033-000-01176-8 $37.00
GPO Order Form
http://www.hq.nasa.gov/office/pao/History/gpo/order.html
Some related Saturn 5 Web sites:
http://www.apollosaturn.com/
http://www.retroweb.com/apollo_retrospective.html
http://aesp.nasa.okstate.edu/fieldguide/booster/index.html
http://www.spacecamp.com/Saturn5/default.asp
Larry
============
(12) AND FINALLY: COSMIC VACUUM CLEANERS
From John B Youles <john.youles@dial.pipex.com>
Dear Benny,
This reminds me of an idea I had which is serious but sounds
funny,
to remove from Earth's orbit all the bits of man-made debris left
from launches and bits of old satellites, flecks of paint, nails,
screwdrivers etc. which are a hazard to spacecraft.
This would be to put into orbit capsules full of gooey stuff
which
would expand, rather like a lifeboat when you pull the cord, in
space. This would create large spheres of stuff rather like the
cross
between expanded polystyrene and school custard (anyone who went
to
an English school in the 1960s will know what I mean). This is
the
same principle I once observed in a place I once stayed where
someone
threw a piece of cutlery into the air, and it got stuck in the
ceiling which was made of those cheap polystyrene tiles.
The stuff would have to be firm enough not to shatter on impact,
but
be soft enough to absorb debris. These spheres would sit in
orbit,
obviously large enough not to be a hazard in themselves, but
debris
would stick to and get buried in them and gradually near space
would
be cleaned up. I suppose you could say that it would be,
quite
literally, a "vacuum cleaner"!
Once they had done their work, they would be disposed off, either
by
being nudged into Earth's atmosphere where they would be burnt
up, or
crashing them onto the moon or somewhere.
Regards,
John Youles
----------------------------------------
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