PLEASE NOTE:


*

CCNet 106/2000 - 19 October 2000
--------------------------------


     "The idea that methane has caused extinctions in the past has no more
     credibility than the 'Bermuda Triangle literature.'"

         -- Roger Sassen, Texas A&M University, 18 October 2000


(1) TEXAS FIREBALL IDENTIFIED AS RUSSIAN SATELLITE RE-ENTRY
    Mark Kidger <mrk@ll.iac.es>

(2) WEEKEND METEORS
    NASA Science News for October 18, 2000

(3) EROS IS NASA'S LITTLE PRINCE
    Larry Klaes <lklaes@bbn.com>

(4) NEAR AT EROS: DANCING THE TANGO
    Ron Baalke <baalke@zagami.jpl.nasa.gov>

(5) PRECOVERY WORK ON NEAS
    Andrea Boattini <boattini@ias.rm.cnr.it>

(6) GLOBAL WARMING SCARE GOES OTT: DID IT CAUSE MASS EXTINCTION 55 MYA?
    Boston Globe, 17 October 2000

(7) DON'T LAUGH: CLIMATOLOGISTS CLAIM COLD WINTERS CAUSED MASS EXTINCTION 34
MYA
    The New York Times, 19 October 2000

(8) NO EVIDENCE OF DEGLACIATION
    CO2 Science, 18 October 2000

(9) 6000 YEARS OF SEA LEVEL CHANGE IN THE SOUTHERN HEMISPHERE
    CO2 Science, 18 October 2000

(10) SPACE EXPLORATION: THE CHINESE CENTURY?
     Michael Martin-Smith <martin@miff.demon.co.uk>

==========
(1) TEXAS FIREBALL IDENTIFIED AS RUSSIAN SATELLITE RE-ENTRY

From Mark Kidger <mrk@ll.iac.es>

Dear Benny:

The bright fireball seen over Texas, Oklahoma and Kansas on the 13th has now
almost certainly been identified as the re-entry of the Proton booster of a
Russian Glonas satellite. The groundtrack of the booster, calculated by Alan
Pickup

http://www2.satellite.eu.org/sat/seesat/Oct-2000/0235.html

agrees well with the estimated groundtrack of the fireball.

Curiously, a NORAD spokeperson has suggested that the fireball may have been
an early Orionid meteor, but this now seems highly unlikely.

More detailed information on the event can be found at

http://meteors.com/cometlinear/index.shtml

Unlike the Los Alamos fireball reported on CCNet recently, this event is
almost certainly man-made.

Mark Kidger

=============
(2) WEEKEND METEORS

From NASA Science News <snglist@lyris.msfc.nasa.gov>

NASA Science News for October 18, 2000
http://science.nasa.gov/headlines/y2000/ast18oct_1.htm?list20392

October 18, 2000 -- Last Friday, the 13th of October, thousands of
high-school football spectators were gathered in outdoor stadiums across the
Midwestern US when something happened to distract even diehard fans from
action on the field below.

With no warning, a fiery meteor as bright as the full Moon streaked over
Texas, Oklahoma, and Kansas around 7:30 p.m. local time. It was a halftime
show from the heavens!

"At first I thought it was a high-flying aircraft with its landings light
on," recounts Alex Leslie, who saw the meteor from a Hill City, Kansas,
football game. "As it passed almost directly south of us, it separated into
about five burning points, mainly white but some green hues, too. A 'smoke
trail' lingered for some time after the object passed. It took about five
minutes to cross the entire sky."

Emergency phone lines were jammed with UFO reports soon after the sighting,
but in this case the strange lights were not from outer space. The object
that slowly burned across Texas skies had left Earth only hours before.

Earlier on Friday a trio of Glonass satellites lifted off from the Baikonur
Cosmodrome in Kazakstan aboard a single Russian Proton rocket. Glonass is
the Russian equivalent of the American Global Positioning System. The
successful launch added three new satellites to the Glonass array and,
unintentionally, triggered the Friday night sky show over Texas.

"In my opinion, the [Texas fireball] was the re-entry of the Proton rocket's
4th-stage casing," says Alan Pickup, a satellite decay expert who works at
the United Kingdom's Astronomy Technology Centre at the Royal Observatory in
Edinburgh. "It was a cylinder 3.7m in diameter and 4m long that weighs some
800 kg."

"The object had passed through perigee (closest approach to Earth) at 7:19
p.m. Central Daylight Time (00:19 UT) when it was over the eastern Pacific
en route to the Mexico coast. It would have passed 3.1 degrees west of
Abilene, Texas, at 7:25 p.m. (00:25 UT) and almost directly over Lubbock,
Texas, 19 seconds later. Its track continued over Oklahoma and Kansas
towards Lincoln, Nebraska, which it would have reached at about 7:27 p.m.
local time were it still in orbit."

But there is a real meteor shower in store this weekend for erstwhile star
gazers inspired by Friday's fiery display.

Earlier this month our Earth's orbit carried our planet into a diffuse
stream of dusty debris from Halley's comet. Until now we've been in the
rarefied outskirts of the debris field, but we're heading for denser parts.
Tiny bits of Halley dust that burn up in our planet's atmosphere will
produce a meteor shower, called the Orionids, that peaks this weekend,
October 21st and 22nd. Orionid meteors won't be nearly as bright as a
decaying Proton rocket shell, but the display should be nonetheless
pleasing.

Earth passes close to the orbit of Halley's comet twice a year, once in May
and again in October. Although the comet itself is very far away --
presently beyond the orbit of Jupiter -- tiny pieces of Halley are still
moving through the inner solar system. These particles are leftovers from
Halley's close encounters with the Sun every 76 years; each time the comet
returns, solar heating evaporates about 6 meters of ice and rock from the
nucleus. The debris particles, usually no bigger than grains of sand,
gradually spread along the comet's orbit until it is almost uniformly filled
with tiny meteoroids. When these meteoroids strike Earth's atmosphere they
produce the Orionid meteors in October and the eta Aquarid meteors in May.

No matter where you live, the best time to see Orionid meteors will be
during the hours before dawn on October 20th through 23rd. Rural observers
should enjoy as many as 20 shooting stars per hour. During this year's broad
peak, centered approximately on Oct. 21st, the light of the waning quarter
Moon will make faint meteors hard to spot; pre-dawn observers on the 22nd
and 23rd may have better luck with diminishing moonlight.

Orionid meteoroids are fast. They hit the atmosphere at a head-spinning
velocity of 90,000 mph. There's no danger, though, because the tiny specks
of dust disintegrate well above the stratosphere. True to their name, the
Orionids will appear to stream from the constellation Orion, which is high
in the southern sky before dawn. The best place to look for meteors is not,
however, directly toward Orion. Orionids can appear anywhere in the sky,
with tails that point back to the shower's radiant above Orion's left
shoulder. Experienced meteor watchers suggest looking 90 degrees away from
the constellation -- that's usually the best direction to watch Orionids fly
by. Also, try to choose a dark area of the sky away from the bright Moon.

Even if the usually-reliable Orionids fail to produce a pleasing show,
there's still plenty to see. October's glittering pre-dawn sky includes
Jupiter, Saturn, and the brightest star of all, Sirius -- all near to the
Orionids radiant. Waking up early for this weekend's meteors is a no-lose
proposition!

=============
(3) EROS IS NASA'S LITTLE PRINCE

From Larry Klaes <lklaes@bbn.com>

From Boston Globe, 17 October 2000
http://www.boston.com/dailyglobe2/291/science/Eros_is_NASA_s_Little_Prince+.shtml

By Chet Raymo, Globe Correspondent, 10/17/2000

Antoine de Saint-Exupery's "Little Prince" lived on an asteroid scarcely
larger than himself. As readers of the childhood classic will remember, his
companions were a sheep and a rose, and some baobab seedlings that he
carefully weeded, lest they grow into giant trees that would split his tiny
world. The asteroid had three volcanoes, two of which were active, and all
of which the Little Prince assiduously cleaned.

A charming little world, but of course scientifically implausible. An
asteroid the size of the Little Prince's would not have enough internal heat
to cause volcanic activity, nor enough gravity to hold an atmosphere. Water
too would be absent, and surface temperatures would be either too hot or too
cold for comfort.

For his journey to Earth, the Little Prince took advantage of the migration
of a flock of wild birds, to which he attached himself with cords. On a
world as small as his, birds might well provide enough propulsive power to
effect an escape - if only there were air in space in which to fly.

Where children fly in their imaginations, NASA takes us in reality. On Feb.
17, 1996, the NEAR, or Near Earth Asteroid Rendezvous spacecraft was
launched on a four-year voyage to the asteroid, Eros. Not a flock of wild
birds but a Delta rocket with nine strap-on boosters lifted the car-sized
craft away from Earth and sent it on its way.

Eros is not so far away. It doesn't circle in the asteroid belt between Mars
and Jupiter, but on an eccentric orbit that takes it nearly as close to the
sun as Earth, and out just past Mars. Eros was the first near-Earth asteroid
to be discovered, and the second biggest. It is a potato-shaped chunk of
rock about the size of Martha's Vineyard. Not as small as The Little
Prince's world, but small enough to circumnavigate in a brisk day's walk.

NEAR's voyage to Eros took four years. A three-year journey was planned, but
the first attempt to put the spacecraft into orbit around the asteroid
failed. An extra year's travel gave engineers time to trim their skills and
calculations. And it allowed NEAR to rendezvous with an asteroid named for
the god of love on Valentine's Day 2000.

An object as small as Eros doesn't have much gravity to hold a spacecraft in
orbit. The Little Prince would weigh about an ounce on Eros, and he could
launch a stone into space with a swing of his arm. NEAR is bound to Eros by
a slender gravitational thread, and slipping the spacecraft into the thrall
of the asteroid was a tour de force of remote navigation.

Since April, NEAR has been orbiting just above the lumpy surface of Eros,
sending back stunning pictures of a gray and lifeless world without air or
water (http://near.jhuapl.edu). No sheep or baobabs, but lots of impact
craters and scattered boulders. We are catching a glimpse into the early
history of the solar system, when scattered dust and gas was gathered into
larger and larger chunks of rock, some of which would eventually coalesce to
form the planets, and others that were destined to drift through space like
gloomy Flying Dutchmans.

That's exactly the impression one gets from the NEAR photos of Eros. It's as
if a manned boat had pulled aside the spectral galleon of seafaring myth,
hailing without answer for a human response. The lifeless asteroid sails on
in dusty solitude, grimly colorless and deathly silent, reminding us of just
how extraordinary and rare is life in the universe.

A recent issue of the journal Science brought us the first summary reports
from NEAR. We have the mass, shape, rotation rate, elemental composition,
and even something of the asteroid's internal structure. The potato-shaped
rock named after the god of love is no longer just a speck of light in a
telescope; it is now a world as exactly accessible to our imaginations as
the Little Prince's domicile.

Astronomer's have charted about 250 near-Earth asteroids, and there may be
as many as 1,000 with a diameter of a half-mile or more. A few of these are
probably destined to collide with Earth at some time in the future, as other
asteroids have done in the past. If something like Eros came smashing our
way, we would be in big, big trouble indeed. Fortunately, Eros is on an
orbit that will keep it safely out of the way.

But NASA scientists plan to get our licks in first, anyway. Next year, two
days before the first anniversary of the Valentine's Day rendezvous, NEAR
will be caused to collide with Eros while the scientists listen - one last
attempt to extract information from an asteroid that has been clobbered
enough in its long history to withstand a gentle assault from Earth.

Chet Raymo is a professor of physics at Stonehill College and the author of
several books on science.

This story ran on page F2 of the Boston Globe on 10/17/2000.
Copyright 2000 Globe Newspaper Company.

================
(4) NEAR AT EROS: DANCING THE TANGO

From Ron Baalke <baalke@zagami.jpl.nasa.gov>

http://near.jhuapl.edu/news/sci_updates/00oct17.html

          NEAR Shoemaker Science Update
          October 17, 2000

          Dancing the Tango

          NEAR is now eight months into its year-long rendezvous
          with Eros. We have seen Eros from as low as 35 km orbit
          for about ten days back in July, but then returned to
          higher altitude. For the last five weeks, we have been
          mapping Eros from 100 km orbit, but we are now preparing
          for our closest descent yet, a 6 km flyover scheduled
          for October 25, 2000. Why has NEAR Shoemaker performed
          this elaborate tango with Eros? One answer is that we
          chose one of the most attractive partners on the dance
          floor, and we have to pay the price if we wish to dance
          very close - it costs extra fuel and requires frequent
          maneuvers. But another reason for dancing both up close
          and farther out is that we scientists want it that way.

          The design of the mission has been the result of a
          complicated interplay between science and engineering
          requirements. To start with, NEAR Shoemaker was designed
          as a simple spacecraft, with fixed antennas, fixed solar
          panels, and fixed instruments. This simplicity makes for
          a more reliable and robust spacecraft, but it also
          places operational constraints on the mission. The
          spacecraft must always keep its solar panels pointed at
          the sun - it cannot survive even for an hour without
          solar power, not only because the electronics would stop
          operating, but also because instruments and subsystems
          would be damaged by cold and the fuel would quickly
          freeze. The instruments must be pointed at the asteroid
          in order to acquire data. The main antenna must be
          pointed at Earth to send data back to Earth at high
          rate, although the spacecraft status can be monitored
          and the spacecraft can be tracked at lower data rates
          using other antennas, even when the main antenna is not
          pointed at Earth. If we had designed a more complex
          spacecraft, we could have lifted many or all of the
          operational constraints, but it would have cost more.
          And indeed these restrictions complicate the day-to-day
          operations of the spacecraft, but it turns out that the
          ever-vigilant enforcement of simple rules is a task
          better suited for computers than for humans, and this
          task is largely automated for NEAR. Paradoxically, the
          use of a simple spacecraft leads to an overall
          simplification of mission operations, despite
          operational restrictions, because there are fewer
          options to be studied.

          In any case, the spacecraft design constrains NEAR
          Shoemaker to fly in an orbit plane that is within about
          30 degrees of perpendicular to the line from Eros to the
          Sun. The spacecraft can then keep its solar panels
          pointed at or close enough to the Sun at all times,
          while for 16 hours a day it keeps the instruments
          pointed at Eros for data taking, and for 8 hours a day
          it points the main antenna at Earth for data
          transmission. This tight constraint on the orbit plane
          at Eros, plus the constraint that the orbit is flown at
          a particular time, already fairly well settle three of
          the six parameters required to specify an orbit
          completely. In some sense the orbit is now almost
          halfway designed, although in real life our engineers
          determine these parameters to 10 decimal places. Those
          of us who don't actually have to fly the spacecraft can
          afford to take a more relaxed attitude. The remaining
          three orbit parameters deal with how low and how high
          the orbit goes, and precisely where it dips low.

          That is where science comes in, although even at this
          point operational constraints are still critical. Some
          of our science operations are best performed at higher
          altitudes, while others require that the spacecraft be
          at low altitude. For instance, our imaging team desires
          to map the whole asteroid under a variety of lighting
          conditions and from a series of orbit radii,
          specifically 200 km, 100km, and 50 km. In addition, the
          team requires both monochrome (black-and-white) and
          color imaging, and the ideal lighting conditions for the
          one are not ideal for the other. For monochrome images,
          we prefer the sun to be low in the sky so that shadows
          accentuate the structures, whereas for color images we
          prefer the sun to be higher to reduce the shadowing. In
          addition, there are seasons on the asteroid. Until late
          June of this year, portions of the southern hemisphere
          never came into sunlight at all. The reverse is now true
          in the southern hemisphere summer, when the north polar
          region is always in the dark. Beyond all these
          requirements, the x-ray and gamma ray teams need to have
          the spacecraft in low orbits of 50 km or less as long as
          possible to achieve the highest possible signal-to-noise
          ratio. Also the laser rangefinder team obtains the
          highest resolution and measurement accuracy in the low
          orbits, and the study of the asteroid's interior
          structure, through determination of its gravity and
          magnetic fields, achieves the highest sensitivity in the
          low orbits.

          So there are many science tasks that require low orbits,
          but there are also science tasks that require high
          orbits, and in both cases, the spacecraft is required to
          fly over all parts of the asteroid at the altitudes in
          question. In addition, particular solar illumination
          geometries are often required, such as for color and
          spectral observations as well as the x-ray measurements.
          Hence the choices of how low to fly, and where, and
          when, are complicated, and we really needed to spend a
          full year at Eros. Moreover, there are engineering
          requirements which derive from orbit stability. The
          spacecraft cannot be put into an orbit that would be so
          unstable that we could not predict with sufficient
          accuracy where it would be a week later, or so unstable
          that, if for any reason we could not contact the
          spacecraft or correct its orbit for a week, it would
          crash or escape from the asteroid. Furthermore, we avoid
          orbits that would require excessive fuel expenditures or
          corrective maneuvers more often than once a week.
          Finally, we cannot send the spacecraft into an orbit
          that would carry it into the shadow of the asteroid,
          where the Sun would be eclipsed and the spacecraft would
          die.

          Generally speaking, the orbits we need to worry about
          are the low orbits. As we discussed earlier (April 18,
          2000), the irregularity of an object's shape produces
          greater and greater distortions of its gravity field,
          the closer one approaches to the object. At large
          distances from any object, its gravity field becomes
          monopolar and spherical, so higher orbits tend to be
          better behaved in terms of being more like ordinary
          elliptical orbits. There is a caveat, which is that the
          gravity from the object must remain the biggest force
          field around; if we get too far from the object, then we
          also have to worry about other forces like solar gravity
          and radiation pressure, and orbits become complicated
          again. For Eros, too high in this sense means above
          about 1000 km. Hence the 200 km orbits are fairly stable
          and ordinary - that is, not too close and not too far.
          The 50 km orbits, on the other hand, are close enough to
          be strongly perturbed by the irregular shape of Eros.
          The most serious disturbance is that the orbit plane is
          continually torqued around (that is, it precesses), so
          it would quickly violate the operational constraint we
          started with unless we perform maneuvers to correct the
          orbit. In other words, we need to fire the rocket
          engines to keep the orbit plane within the allowed
          angles to the line from Eros to the Sun. It turns out
          that the precession rate depends on the orbital
          inclination to the Eros equator as well as the orbital
          radius.

          The upshot is, there are only certain times of year when
          NEAR Shoemaker can fly in 50 km orbits or lower, without
          using too much fuel or putting the spacecraft at too
          much risk. Even so, we have no choice but to get up
          close to Eros to make the measurements we need. This is
          why we are dancing a tango with Eros, sometimes close,
          and sometimes far. Like the real tango, our dance with
          Eros has been exciting, full of mystery, and much hard
          work - and more is still to come. Our closest view of
          the surface to date is eight days away.

     Andrew Cheng
     NEAR Project Scientist               

================
(5) PRECOVERY WORK ON NEAS

From Andrea Boattini <boattini@ias.rm.cnr.it>
[as posted on the MPML Mailing list - mpml@egroups.com]

I have posted a brief report of the precovery work done at Edinburgh at:

http://www.arcetri.astro.it/science/aneopp/sumedinb.htm

Also, I want to send my congratulations to Andrew Lowe on his recent
NEA precoveries using DSS images.

Best regards,
Andrea Boattini

===============================================
Andrea Boattini
IAS-CNR, Area di Ricerca Tor Vergata
Via Fosso del Cavaliere 100
00133 Roma, ITALY

Phone: +39-06-49934448
Fax: +39-06-20660188
E-mail: boattini@ias.rm.cnr.it
===============================================

http://www.arcetri.astro.it/science/aneopp/sumedinb.htm

Looking for NEOs on the UK Schmidt Archive: a Preliminary Report

One of the most extensive and well maintained photographic archives in the
world, is the UK Schmidt archive. Although some of its data is available
through the web as part of the Digitized Sky Survey, the great bulk of this
resource is kept at the Royal Observatory, Edinburgh (ROE). About 17,000
plates are there at any time.

The UKST archive has always represented a great potential for NEO precovery
work. Considering the amount of success of other similar programs from the
early 90's, we realized that a visit to ROE was worthwhile at this stage of
the NEO discovery process. All single-opposition and a few
multiple-opposition NEOs were checked against the UKST catalog file. Each
target output was divided into a few different categories depending on the
likelihood of locating the object.

A collaboration was established with ROE staff for the use of their plate
library, and we arranged a visit from September 19 to to October 3, 2000.
The work at ROE plate library, (object searching and astrometry) was done by
Andrea Boattini. All the computational work, "last-minute" observing
predictions and orbital linkages of possible candidates, was performed by
Giuseppe Forti from Arcetri Observatory. Technical assistance at ROE plate
library was provided by Mike Read and occasionally by Sue Tritton. We plan
to arrange another visit in the near future, as soon as there is enough
material and/or we have valuable scientific expectations to justify another
trip to this nice facility.

Here is a brief summary of the results:

* NEOs found and measured:   24

One-opposition:   22

1999 RM28 (*), 1998 YB8, 1999 JU3, 2000 JS66, 1998 WM, 1999 KX4, 1999 RR28,
2000 QP,
1998 OR2, 2000 EZ148, 1998 UT18, 1998 BX7, 1999 GJ2, 1992 BL2, 1999 YB, 2000
NF11,
2000 SY2, 1999 JV3, 1999 LQ28, 1999 RP36, 2000 JT66, 2000 PG5

(*) located and measured by R. H. McNaught at Siding Spring Observatory.


Multi-opposition:   3
1997 WS22, 1996 AS1, 2000 SY2   (addit. image)

* NEOs found but not measured (either plate defects or too faint for
astrometry):   6

1997 XF11, 1998 UL1, 1999 AR7, 1999 CT3, 1999 DB7, 2000 JQ66

* NEAs not found (either too faint, not recognized, or out of plate):   61

1977 VA, 1978 CA, 1983 LB, 1987 SF3, 1988 RO1, 1988 SM, 1991 FB, 1993 HC,
1995 QN3,
1996 PC1, 1997 AQ18, 1998 CS1, 1998 HM3, 1998 HJ41, 1998 ME3, 1998 QE2, 1998
SV4,
1998 SF35, 1998 SR49, 1998 VR, 1998 YM4, 1999 CZ136, 1999 FB, 1999 GT6, 1999
HV1,
1999 KK1, 1999 LN28, 1999 MN, 1999 SK10, 1999 TB10, 1999 VQ6, 1999 WA2, 1999
YA,
1999 YN4, 2000 BH19, 2000 CK33, 2000 CN33, 2000 CE59, 2000 CF59, 2000 CH59,
2000 CO101,
2000 EV70, 2000 EE104, 2000 EA107, 2000 FL10, 2000 FN10, 2000 FO10, 2000
GX127, 2000 GK137,
2000 HW23, 2000 JH5, 2000 JO78, 2000 OJ8, 2000 OB22, 2000 PJ5, 2000 QT7,
2000 QU7,
2000 QW69, 2000 RD34, 2000 RJ34, 2000 RH60

The above lists involved about 150 plates. Among the best finds, we can
mention the lost Amor 1992 BL2 and the Aten 2000 SY2, which was located
about three hours after the discovery announcement by the MPC. We also
discovered one Hungaria (1977 SU3); it happened to be on four plates leading
to a 55-days arc orbit. Another set of 150 plates have been used to search
for a few lost objects, such as:

1937 UB, 1950 DA, 1991 NT3, 1991 TB2, 1998 FH74, 2000 KB

There was not enough time to make a full investigation of these targets, but
in the case of 1991 NT3 the coverage of the confidence region was almost
complete. We plan to use this information for a direct recovery at the
telescope.

Note: A few plates we were interested in, were not at the ROE plate library.
On one of these, 1999 RM28, was located measured by Robert McNaught at
Siding Spring Observatory. Another plate where supposedly 1999 LP28 was
recorded, is currently in Japan.

Acknowledgements

We want to thank all the institutions that made this collaboration possible:
the Royal Observatory at Edinburgh, the Rome Observatory and the Arcetri
Observatory. Also, I want to send my congratulations to Andrew Lowe on his
recent NEA precoveries using DSS images.

===========
(6) GLOBAL WARMING SCARE GOES OTT: DID IT CAUSE MASS EXTINCTION 55 MYA?

From Boston Globe, 17 October 2000
http://www.boston.com/dailyglobe2/291/science/Gas_attack+.shtml

Gas attack

It seems as harmless as a wilted flower, but methane gas once caused a mass
extinction. It could happen again

By Gareth Cook, Globe Staff, 10/17/2000

Under the long shadow of the freshly carved Rocky Mountains, delicate
creatures that looked like a cross between a squirrel and a monkey noisily
foraged for food in the dense canopy of broad-leafed banana trees. Off the
coast of Florida, dozens of species of tiny animals called foraminifera
swarmed through the cerulean seas.

Then, in a geological instant, came chaos.

With a speed that has long baffled climatologists, the world's temperatures
suddenly soared 55 million years ago, opening northern land routes between
the continents. Whole families of archaic animals, including the squawking
squirrel-monkies (plesiadapiformes), were doomed as an army of new animals -
including the dawn horse and ancestors of modern pigs and primates - invaded
over the new land bridges.

In the water, meanwhile, vast regions lost their oxygen, killing off half
the species of foraminifera in a massacre so devastating that some
researchers refer to the result of the mass die-off as a "Strangelove ocean"
- a nod to the classic film about nuclear annihilation.

But the assassin, many scientists now think, was not the kind of fiery
asteroid that felled the dinosaurs: it was a great belch of methane gas from
deep in the ocean. In the atmosphere, methane can trap the sun's heat with
21 times the power of carbon dioxide. If even a small part of frozen
deep-sea methane were to escape, computer models show, it could easily
change the narrative of life.

And the trigger behind this ancient extinction, one leading theory holds, is
a phenomenon with modern relevance: global warming. Then, as now, the
earth's temperatures were slowly rising. Scientists think that the warming
might have melted some of the methane, which would have caused more warming
- setting off a chain reaction of disastrous methane releases.

"The fossil record shows that it's possible to have a catastrophic change
that was triggered by slow warming," said Paul Olsen, a Columbia University
geologist who has studied the web of emerging connections between the
planet's geological and biological history. "The links to the modern world
are obvious."

Olsen and other specialists emphasized that it's too early to worry that our
cars, factories and power plants are poised to set off a methane disaster,
because nobody has been able to prove precisely how it happened. But,
whatever the cause, they said there is tantalizing evidence methane has
exploded into the atmosphere at several points in earth's long history and
that, at some point, it will likely happen again.

"The more we recognize it as happening in the past, the more we should think
seriously about it happening in the present day," said British scientist
Stephen Hesselbo, co-author of a July report in the journal Nature that
provided evidence of a massive methane release 183 million years ago.

Methane, frozen in fields of grayish-white ice crystals, has attracted
increasing attention from scientists in range of disciplines, who say that
the gas could play a much more dramatic role in our future than anyone
imagined a decade ago. Mixed with sedimentary rock, as it is off America's
East Coast, escaping methane can trigger roiling underwater landslides, and
perhaps even tsunamis.

On the other hand, in it's purer form, found in parts of the Gulf of Mexico,
methane could be a solution to the coming global energy shortage when fossil
fuels such as oil run out.

"The amount of methane down there is enormous," said Keith Kvenvolden, an
energy specialist with the United States Geological Survey in Menlo Park,
California. Kvenvolden, who wrote a 1999 paper for the Proceedings of the
National Academy of Sciences on the promise and perils of the gas, estimated
that there are about 10,000 billion tons of carbon in methane - twice the
known reserves of coal, oil and gas combined.

Methane, formed when one carbon atom joins four hydrogen atoms, is a
familiar organic compound given off by bacteria as they consume decaying
plant life. Invisible and scentless, the suffocating gas is one of the
reasons miners would want to bring a canary with them. And the gas's
incendiary tendencies are thought to have been inspiration for stories of
"will-o-the-wisps," fairy-tale lights that danced in swamps.

But, until three decades ago, nobody knew that the oceans held deposits of
methane hydrate, as the crystals are called.

When dead organic materials settle to the ocean floor, it is set upon by
bacteria that give off methane. Under the cold and crushing pressures of the
depths, this methane forms hard crystals. Given millions of years, the
process generates immense quantities of methane.

Scientists who study the planet's past climate then realized that the
discovery of the deposits might explain sudden temperature jumps.

Researchers already knew that large amounts of organic carbon had suddenly
appeared in the atmosphere, which would naturally trap heat and drive global
temperatures up. But they could not identify any candidates for a source.

With the methane discovery, they pieced together a scenario that could bring
warm water to the ocean bottom and melt the methane ice.

It begins with gradual warming, caused perhaps by the volcanic release of
carbon dioxide. This would increase the evaporation of sea water at the
equator, leaving it saltier, and, thus, heavier. This heavy, warm water
would then plunge down and start the cycle, explained Ellen Thomas, a
research professor at Wesleyan University.

That would explain why a number of prominent extinctions are associated with
volcanic activity, Olsen said.

There is also evidence, off the coast of Florida, of a catastrophic
underwater landslide at precisely the time when all the changes came 55
million years ago, according to Miriam Katz, a marine geologist at Rutgers
University who published her findings last fall in the journal Science.

Using a drill to draw up cores of earth from the sea floor, Katz and her
colleagues found a level, sandwiched between neat sedimentary layers, of
turbulent mixing, suggesting sudden changes in the landscape. This layer
corresponded to a period of avalanches, with sections calving off and
plunging down, said Katz, who is still researching the ways methane might be
released from the sea bottom.

To those who try to map our climate future, methane is a well-known
greenhouse gas. But most scientists agree that the threat of major releases
is not a threat in the near term, certainly not in our lifetimes, said
Kvenvolden.

It would take a major change in the ocean system to knock methane hydrate
from the cold deep where it resides. And, other scientists added, the only
times where methane has so far been implicated in major climate shifts were
periods where the ocean waters were warmer than they are now.

But the threat of methane is a reminder that complex systems can have
"threshold points," where dramatic change comes quickly and without warning.

Already, some climatologists are worried that dumping carbon dioxide into
the atmosphere could bring a sudden reversal in the deep ocean currents,
also called the ocean "conveyor belt" - that carries water from the equators
to the poles and back. Even without the danger of methane elease, such a
shift could bring bitter winters to temperate climates.

"Looking at the planet's past provides natural experiments that gives us
insights into processes that we wouldn't otherwise be able to understand,"
said Olsen.

With the world's energy reserves rapidly depleting, methane hydrate could
yet alter human history in this generation.

"Within twenty or thirty years, the era of permanent decline in oil and gas
production will begin," said Roger Sassen, a research geologist with Texas
A&M University. Sassen, who has done extensive work in the Gulf of Mexico,
predicted that energy companies would be selling methane fuel from the Gulf
within two decades.

Sassen, who has seen rising methane bubbles there click and pop around
ships, said that the Gulf holds layers, some a kilometer thick, of the ice
on its floor, visible from a submarine. He says the idea that methane has
caused extinctions in the past has no more credibility than the "Bermuda
Triangle literature."

Yet nobody has yet offered another convincing explanation for the kinds of
carbon that suddenly appeared in the atmosphere.

Indeed, to others, it is a theory both compelling and humbling: that
deposits which were only discovered in the last three decades have played
such an important role in the drama of evolution. Paleontologists have long
known that the dawning of the Eocene Epoch 55 million years ago was the
beginning of the modern era of mammals - with humans to become the most
successful of the new creatures - but they didn't know what caused it.

"It's amazing that changes in the deep oceans could cause the dispersal of
new mammals across the land," said William Clyde, a specialist of mammalian
evolution at the University of New Hampshire. "It's amazing there are all
these connections."

This story ran on page F1 of the Boston Globe on 10/17/2000.
Copyright 2000 Globe Newspaper Company.

===========
(7) DON'T LAUGH: CLIMATOLOGISTS CLAIM COLD WINTERS CAUSED MASS EXTINCTION 34
MYA

From The New York Times, 19 October 2000
http://www.nytimes.com/2000/10/19/science/science-extinction.html

Climate Change Led to Mass Extinction 34 Million Years Ago

By REUTERS
 
LONDON, Oct 18 - Severe climate changes 34 million years ago wiped out 90
percent of all tiny sea creatures living along the Gulf Coast in the United
States, scientists said on Wednesday.

Until now, researchers had been mystified by the largest extinction since
the dinosaurs disappeared 65 million years ago, but new evidence reported in
the science journal Nature shows it was caused by extremely cold winters.

"We found that while the summer temperatures remained the same, winter
temperatures dropped four degrees Celsius (seven degrees Fahrenheit)," said
Linda Ivany of Syracuse University in New York.

"Palaeontologists had a suspicion that temperature had something to do with
the extinction crisis because of the pattern of extinction but there was no
quantitative demonstration of any kind of temperature change," she added in
a telephone interview.

Ivany and scientists at the University of Michigan used a novel technique to
study ancient climate changes by determining seasonal variations in the
temperature of the water in the Gulf.

They analysed the chemical composition of fossilised samples of minuscule
structures, called otoliths, in the ears of fish that lived in the Gulf at
the time.

"The otoliths are made of calcium carbonate and they grow accretively, just
like tree rings. They produce layer after layer after layer as the fish
grows," said Ivany.

The chemical composition of that material changes according to the
temperature of the water in which the fish live.

"This is the first time anyone has looked at seasonality as a variable for
an extinction event across a geological time boundary," William Patterson,
who contributed to the research, said in a statement.

"We proved that winter temperatures caused the extinction. Existing records
weren't able to resolve the change because the records are based on
summertime growth. The fish survived the drop in winter temperatures and
left a permanent record, while molluscs didn't make it."

Harry Elderfield of the University of Cambridge in England described the
research as a fascinating example of high-resolution analysis of climate
change.

"They show that although inferred temperatures did not change...seasonality
did; summer temperatures remained the same but winters became cooler," he
said.
 
Copyright 2000 The New York Times Company

===========
(8) NO EVIDENCE OF DEGLACIATION

From CO2 Science, 18 October 2000

http://www.co2science.org/journal/2000/v3n27c1.htm

The Need for Long-Term Glacier Mass Balance Data

Reference

Braithwaite, R.J. and Zhang, Y. 2000. Relationships between interannual
variability of glacier mass balance and climate. Journal of Glaciology 45:
456-462.

What was done
With respect to the ongoing quest to determine the nature and magnitude of
long-term climate change, which typically focuses on detecting presumed
anthropogenic-induced global warming, the authors note that "any putative
trend of increasingly negative mass balance [of glaciers or ice sheets] has
to be detected against the background of year-to-year variations." In view
of this requirement, they explore the relationship between long-term mass
balance and interannual variability in the totality of earth's glaciers for
which such data exist.

What was learned
The authors begin by noting there are over 200 glaciers for which mass
balance data exist for at least one year. When the length-of-record
criterion is increased to five years, this number drops to 115; and if both
winter and summer mass balances are required, the number drops to 79.
Furthermore, if ten years of record is used as a cutoff point, only 42
glaciers qualify; and more stringent requirements result in much lower
numbers. At the extreme record length of 50 years is the Storglaciaren of
northern Sweden, which exhibited a negative mass balance of little trend for
the first 15 years of record but which then began to trend upward, actually
becoming positive over about the last decade.

Working with various sets of these glaciers, the authors develop
relationships that allow them to calculate how long a period of mass balance
measurements would be required to determine whether or not the Greenland ice
sheet was in a state of flux or equilibrium. They conclude that "the ice
sheet can thicken or thin by several meters over 20-30 years without giving
statistically significant evidence of non-zero balance under present
climate."

What it means
In the words of the authors, "one of the most important problems for
mass-balance glaciology, after more than 50 years of hard work, is the sad
fact that many glacierized regions of the world remain unsampled, or only
poorly sampled," suggesting that we really know very little about the true
state of balance of most of the world's glaciers. As for the Greenland ice
sheet, they conclude that it might "have to be monitored over many decades
to detect unambiguous evidence of either thinning, due to increased melting,
or thickening, due to increased accumulation."

The moral of the story? Don't hold your breath waiting for a definitive
answer about the state of the Greenland ice sheet. And without a definitive
answer, don't jump to conclusions; you'll only be speculating. In the case
of the glacier with the longest mass balance on record, however, we need not
speculate. It is clear there has been a significant upward trend in its mass
balance state over the past 30-40 years and that it has been in a mass
accumulation state for at least the past decade.
 
Reviewed 18 October 2000

================
(9) 6000 YEARS OF SEA LEVEL CHANGE IN THE SOUTHERN HEMISPHERE
 
From CO2 Science, 18 October 2000
http://www.co2science.org/journal/2000/v3n27c4.htm

References

Baker, R.G.V. and Haworth, R.J. 2000. Smooth or oscillating late Holocene
sea-level curve? Evidence from cross-regional statistical regressions of
fixed biological indicators. Marine Geology 163: 353-365.

Baker, R.G.V. and Haworth, R.J. 2000. Smooth or oscillating late Holocene
sea-level curve? Evidence from the palaeo-zoology of fixed biological
indicators in east Australia and beyond. Marine Geology 163: 367-386.

What was done
The authors present substantial evidence that sea-level, as measured over
large portions of the Southern Hemisphere, has declined significantly since
approximately 6,000 years ago. But has the journey been smooth or
oscillatory? In attempting to answer this question, they review data,
including much of their own, obtained from a number of different places in
the non-glaciated, tectonically-stable regions of the Southern Hemisphere.

What was learned
For the period from 6,000 to 600 years before present, the authors
demonstrate that an oscillatory mode of sea-level decline is just as likely
to have occurred, in terms of "statistical justification" based on the
available data, as a smooth decline.

What it means
In the words of the authors, "whether or not sea level has been subject to
low-amplitude fluctuations during the late Holocene (the last ~ 6000 years)
is a subject that has taken on increased importance in view of claims of
possible sea-level rise associated with human-induced global warming." If,
for example, sea-level has oscillated somewhat over this period (the authors
say it could have had an oscillatory amplitude of one meter or more!), it is
possible the sea-level's current rising mode may be nothing more than a
small portion of a natural oscillation having nothing to do with the ongoing
rise in the air's CO2 content. The authors' finding that this type of
sea-level behavior is just as likely to be true as not thus casts a pall of
suspicion over climate alarmist claims that the continued burning of fossil
fuels will lead to the inundation of low-lying coastal areas and islands.

In light of these observations, we can draw some important conclusions about
the way we should approach the future. First, there are those who claim the
continued burning of fossil fuels is nigh unto criminal, because of what
they claim this course of action will ultimately mean for coastal lowlands
and islands, i.e., their submergence beneath the sea.  But if they are wrong
about the cause of the warming, which they believe to be the cause of the
sea-level rise - and this study says there's a fifty-fifty chance they are
wrong on the last point alone - the actions they would have us take could be
viewed as criminal; for reducing CO2 emissions would give the inhabitants of
the threatened regions a false hope of security that would ultimately be
dashed by the inexorable natural rising of the sea, and at a time when it
may be too late to do anything about it, especially if the global economy
suffers irreparable harm from misguided energy policies that could leave it
too weak to help avert the human tragedy that would likely accompany a
sea-level rise of the magnitude the data of these studies suggest is
possible.

This being the case, the Precautionary Principle would seem to suggest that
the nations of the world should begin preparing for a sea-level rise of
precisely the type the climate alarmists are ranting and raving about, not
in terms of trying to avert it, as they propound - especially by incredibly
disruptive measures that could well have absolutely no effect upon it - but
in terms of adapting to it in some way, hopefully in advance and not in
retrospect. To do anything else --and especially something that has no
impact whatsoever upon the problem, costs us dearly in terms of human and
natural resources, and is actually detrimental to our ability to feed
ourselves (remember that CO2 is a tremendous aerial fertilizer)-- is more
than just illogical; it is, as they say, criminal.
 
Reviewed 18 October 2000
Copyright 2000.  Center for the Study of Carbon Dioxide and Global Change

============================
* LETTERS TO THE MODERATOR *
============================

(10) SPACE EXPLORATION: THE CHINESE CENTURY?

From Michael Martin-Smith <martin@miff.demon.co.uk>

Dear Benny,

Bob Kobres points out the possible material benefits of space development to
our civilzation en route to dealing with the threat from NEO impacts. For
those who despair that the West will ever accept such a radical view of our
future, some hope for the species follows below.

It is becoming likely that there will, after all, be humans on the Moon on
or before Apollo's 50th anniversary (2019 AD); fortunately - or
unfortunately according to taste - these will most likely be Chinese,
launched from Jiu Qian. An interesting question is; "How many
Americans/Westerners will view this with equanimity, and how many will blame
their leaders and PC opinion formers for having allowed their nation to follow the
historic fate of Admiral Cheng-Po's voyages under the Ming Dynasty?"

The West should reflect that the 21st century has been called by some
futurologists "the Chinese century". One reason for this will be a growing
realization by China (not least Messrs Jiang Zemin and Zhu Rong-ji)- of the
strategic importance of space exploration, exploitation, and - in due time -
settlement.

The future justly belongs to the far-sighted and adventurous.
--

Dr Michael Martin-Smith, author of "Man, Medicine and Space" to appear in
coming weeks (hopefully!) as a publication available by mail/internet order
from www.iUniverse.com - the 21st century publisher


MODERATOR'S NOTE: Nothing against futurologists, Michael. But the claim that
the 21st century will be a "Chinese century" because of their expanding
space programme reminds me of similar predictions made by the same people,
not too long ago, about the coming "Soviet century." Let's face it; as long
as China remains a brutal dictatorship that suppresses and persecutes
millions of people for their political views and religious beliefs, and
threatens other countries with aggression and invasion, nobody in their
right mind will see the Chinese space programme as a blessing for a healthy
development of our global village. The 20th century experience with
totalitarian regimes (responsible for the killing of some 100 million
people) should have taught us not to fall for their grandiose programmes -
be they giant Olympic stadia or propagandistic  space missions. On the other
hand, if China's young democracy movement were to succeed, and I have little
doubt that freedom and democracy will be established eventually, China would
be more than welcome into the family of free nations. Until such time, we
should advocate human rights and political freedom rather than being blinded
by Chinese space developments.

BJP

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