PLEASE NOTE:
*
CCNet 16/2001 - 30 January 2001
------------------------------
"There is something to be said for history-- Pluto has been
considered a major planet for three generations, not the year or
so that
Ceres was historically called a major planet. I believe that
until
we land on Pluto and find incontrovertible evidence that that
world does
not wish to be called a planet, that we should leave things as
they are.
--David H. Levy, 29 January 2001
"They've done exactly the right thing. It's an emotional
question.
People just don't like the idea that you can change the number of
planets.
It's inevitable that other museums will come around, though. The
Rose center is just slightly ahead of its time."
--David Jewit, University of Hawaii who co-discovered the
first Kuiper Belt object with Jane Lu, a professor
at Leiden University in the Netherlands.
"At the heart of the debate is our very definition of the
word
"planet." Currently, there isn't one. The International
Astronomical
Union (IAU), a worldwide body of astronomers, is the official
keeper
of names. It has no strict definition of a planet, but has
decreed that
there are nine major planets, including Pluto. This, however, is
not very
satisfying. If the IAU doesn't really know what a planet is, how
can it
know there are nine?"
Phil Plait, The Bad Astronomer, Frankfurter Allgemeine
Zeitung, 2 January 2001
"Benny: The IAU may now decide to redirect Mir's fall onto
Liverpool, but you have hit the nail on the head with today's
Pluto
comments."
--Spanish based CCNet subscriber, 29 January 2001
(1) INDIAN DEFENSE MINISTER: QUAKE TOLL 'MAY BE 100,000'
BBC Online News, 30 January 2001
(2) WHAT DRIVES SOCIETAL COLLAPSE
Larry Klaes <lklaes@bbn.com>
(3) SEEDS OF LIFE MAY HAVE REACHED EARTH ON A COMET
The Independent, 30 January 2001
(4) WITHOUT JUPITER, HOME ALONE
NASA Astrobiology Institute, 29 January 2001
(5) ONLY SOLAR SYSTEMS WITH JUPITERS MAY HABOUR LIFE
Andrew Yee <ayee@nova.astro.utoronto.ca>
(6) GENESIS FACTOR: THE TRANSCRIPTS
Michael Paine [mailto:mpaine@tpgi.com.au]
(7) JAPANESE RESEARCHERS PREPARE LAUNCH OF CUBIC SATELLIYES TO
OBSERVE
LEONIDS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(8) FIRST SPACE WAR GAME ALARMS PENTAGON
The Daily Telegraph, 30 January 2001
(9) PLUTO: WHY WE SHOULD LEAVE THINGS AS THEY ARE
David H. Levy <david@jarnac.org>
(10) IS PLUTO A PLANET?
Phil Plait, Frankfurter Allgemeine
Zeitung, 2 January 2001
(11) CAN 'REAL PLANETS' COLLIDE?
Gerrit Verschuur <GVERSCHR@LATTE.MEMPHIS.EDU>
(12) HOW THE NEW PLUTO DEBATE EVOLVED
Kelly Beatty <kbeatty@skypub.com>
==============
(1) INDIAN DEFENSE MINISTER: QUAKE TOLL 'MAY BE 100,000'
From the BBC Online News, 30 January 2001
http://news.bbc.co.uk/hi/english/world/south_asia/newsid_1143000/1143620.stm
India's Defence Minister, George Fernandes, has estimated that as
many as
100,000 people may have died and 200,000 been injured in last
Friday's
devastating earthquake. Gujarati officials however, maintain the
final death
toll is unlikely to exceed 20,000.
FULL COVERAGE at
http://news.bbc.co.uk/hi/english/world/south_asia/newsid_1143000/1143620.stm
============
(2) WHAT DRIVES SOCIETAL COLLAPSE
From Larry Klaes <lklaes@bbn.com>
http://www.sciencemag.org/cgi/content/full/291/5504/609
ARCHAEOLOGY: What Drives Societal Collapse?
Harvey Weiss and Raymond S. Bradley*
The archaeological and historical record is replete with evidence
for
prehistoric, ancient, and premodern societal collapse. These
collapses
occurred quite suddenly and frequently involved regional
abandonment,
replacement of one subsistence base by another (such as
agriculture by
pastoralism), or conversion to a lower energy sociopolitical
organization
(such as local state from interregional empire). Each of these
collapse
episodes has been discussed intensively within the archaeological
community,
commonly leading to the conclusion that combinations of social,
political,
and economic factors were their root causes.
That perspective is now changing with the accumulation of
high-resolution
paleoclimatic data that provide an independent measure of the
timing,
amplitude, and duration of past climate events. These climatic
events were
abrupt, involved new conditions that were unfamiliar to the
inhabitants of
the time, and persisted for decades to centuries. They were
therefore highly
disruptive, leading to societal collapse--an adaptive response to
otherwise
insurmountable stresses (1).
In the Old World, the earliest well-documented example of
societal collapse
is that of the hunting and gathering Natufian communities in
southwest Asia.
About 12,000 years ago, the Natufians abandoned seasonally
nomadic hunting
and gathering activities that required relatively low inputs of
labor to
sustain low population densities and replaced these with new
labor-intensive
subsistence strategies of plant cultivation and animal husbandry.
The
consequences of this agricultural revolution, which was key to
the emergence
of civilization, included orders of magnitude increases in
population growth
and full-time craft specialization and class formation, each the
result of
the ability to generate and deploy agricultural surpluses.
What made the Natufians change their lifestyle so drastically?
Thanks to
better dating control and improved paleoclimatic interpretations,
it is now
clear that this transition coincided with the Younger Dryas
climate episode
about 12,900 to 11,600 years ago. Following the end of the last
glacial
period, when southwest Asia was dominated by arid steppe
vegetation, a shift
to increased seasonality (warm, wet winters and hot, dry summers)
led to the
development of an open oak-terebinth parkland of woods and wild
cereals
across the interior Levant and northern Mesopotamia. This was the
environment exploited initially by the hunting and gathering
Natufian
communities. When cooler and drier conditions abruptly returned
during the
Younger Dryas, the harvests of wild resources dwindled, and
foraging for
these resources could not sustain Natufian subsistence.
They were forced to
transfer settlement and wild cereals to adjacent new locales
where
intentional cultivation was possible (2).
The population and socioeconomic complexity of these early
agricultural
settlements increased until about 6400 B.C., when a second
postglacial
climatic shock altered their developmental trajectory.
Paleoclimatic
evidence documents abrupt climatic change at this time (3), the
last major
climatic event related to the melting continental ice sheets that
flooded
the North Atlantic (4). In the Middle East, a ~200-year drought
forced the
abandonment of agricultural settlements in the Levant and
northern
Mesopotamia (5, 6). The subsequent return to moister conditions
in
Mesopotamia promoted settlement of the Tigris-Euphrates alluvial
plain and
delta, where breachable river levees and seasonal basins may have
encouraged
early southern Mesopotamian irrigation agriculture (7).
By 3500 B.C., urban Late Uruk society flourished in southern
Mesopotamia,
sustained by a system of high-yield cereal irrigation agriculture
with
efficient canal transport. Late Uruk "colony"
settlements were founded
across the dry-farming portions of the Near East (8). But these
colonies and
the expansion of Late Uruk society collapsed suddenly at about
3200-3000
B.C. Archaeologists have puzzled over this collapse for the past
30 years.
Now there are hints in the paleoclimatic record that it may also
be related
to a short (less than 200 year) but severe drought (9-11).
Following the return to wetter conditions, politically
centralized and
class-based urban societies emerged and expanded across the
riverine and
dry-farming landscapes of the Mediterranean, Egypt, and West
Asia. The
Akkadian empire of Mesopotamia, the pyramid-constructing Old
Kingdom
civilization of Egypt, the Harappan 3B civilization of the Indus
valley, and
the Early Bronze III civilizations of Palestine, Greece, and
Crete all
reached their economic peak at about 2300 B.C. This period was
abruptly
terminated before 2200 B.C. by catastrophic drought and cooling
that
generated regional abandonment, collapse, and habitat-tracking.
Paleoclimatic data from numerous sites document changes in the
Mediterranean
westerlies and monsoon rainfall during this event (see the
figure), with
precipitation reductions of up to 30% that diminished
agricultural
production from the Aegean to the Indus (9-11).
Climatic effects. High-resolution lake, marine, and speleothem
cores and
tephrochronostratigraphy document abrupt aridification and
linkage with
Akkadian empire collapse at Tell Leilan, Syria (9-11).
These examples from the Old World illustrate that prehistoric and
early
historic societies--from villages to states or empires--were
highly
vulnerable to climatic disturbances. Many lines of evidence now
point to
climate forcing as the primary agent in repeated social collapse.
High-resolution archaeological records from the New World also
point to
abrupt climatic change as the proximal cause of repeated social
collapse. In
northern coastal Peru, the Moche civilization suffered a ~30-year
drought in
the late 6th century A.D., accompanied by severe flooding. The
capital city
was destroyed, fields and irrigation systems were swept away, and
widespread
famines ensued. The capital city was subsequently moved
northward, and new
adaptive agricultural and architectural technologies were
implemented (12).
Four hundred years later, the agricultural base of the Tiwanaku
civilization
of the central Andes collapsed as a result of a prolonged drought
documented
in ice and in lake sediment cores (13). In Mesoamerica,
lake sediment cores
show that the Classic Maya collapse of the 9th century A.D.
coincided with
the most severe and prolonged drought of that millennium (14). In
North
America, Anasazi agriculture could not sustain three decades of
exceptional
drought and reduced temperatures in the 13th century A.D.,
resulting in
forced regional abandonment (15).
Climate during the past 11,000 years was long believed to have
been
uneventful, but paleoclimatic records increasingly demonstrate
climatic
instability. Multidecadal- to multicentury-length droughts
started
abruptly, were unprecedented in the experience of the existing
societies,
and were highly disruptive to their agricultural foundations
because social
and technological innovations were not available to counter the
rapidity,
amplitude, and duration of changing climatic conditions.
These past climatic changes were unrelated to human activities.
In contrast,
future climatic change will involve both natural and
anthropogenic forces
and will be increasingly dominated by the latter; current
estimates show
that we can expect them to be large and rapid (16). Global
temperature will
rise and atmospheric circulation will change, leading to a
redistribution of
rainfall that is difficult to predict. It is likely, however,
that the
rainfall patterns that societies have come to expect will change,
and the
magnitude of expected temperature changes (17) gives a sense of
the
prospective disruption. These changes will affect a world
population
expected to increase from about 6 billion people today to about 9
to 10
billion by 2050. In spite of technological changes, most of the
world's
people will continue to be subsistence or small-scale market
agriculturalists, who are similarly vulnerable to climatic
fluctuations as
the late prehistoric/early historic societies. Furthermore, in an
increasingly crowded world, habitat-tracking as an adaptive
response will
not be an option.
We do, however, have distinct advantages over societies in the
past because
we can anticipate the future. Although far from perfect and
perhaps subject
to unexpected nonlinearities, general circulation models provide
a road map
for how the climate system is likely to evolve in the future. We
also know
where population growth will be greatest. We must use this
information to
design strategies that minimize the impact of climate change on
societies
that are at greatest risk. This will require substantial
international
cooperation, without which the 21st century will likely witness
unprecedented social disruptions.
References and Notes
1. H. Weiss, in Confronting Natural Disaster: Engaging the Past
to
Understand the Future, G. Bawden and R. Reycraft, Eds. (Univ. of
New
Mexico Press, Albuquerque, 2000), pp. 75-98.
2. O. Bar-Yosef, Radiocarbon 42, 23 (2000).
3. F. Gasse, Quat. Sci. Rev. 19, 189 (2000).
4. This flooding may have altered thermohaline circulation (THC),
although there is as yet no direct paleochemical data
demonstrating a
shutdown or reduction in THC at this time.
5. A. N. Goring-Morris, A. Belfer-Cohen, Pal=E9orient 23, 71
(1997).
6. S. K. Kozlowski, The Eastern Wing of the Fertile Crescent (BAR
Intl.Series 760, Oxford, 1999) [publisher's information].
7. R. M. Adams, Heartland of Cities (Univ. of Chicago Press,
Chicago,
1981).
8. www.science.widener.edu/ssci/mesopotamia=20
9. H. M. Cullen et al., Geology 28, 379 (2000) [GEOREF].=20
10. M. Bar-Matthews et al., Earth and Planetary Science Letters
166, 85
(1999)[ADS].
11. G. Lemcke, M. Sturm, in Third Millennium BC Climate Change
and Old
World Collapse, H. N. Dalfes, G. Kukla, H. Weiss, Eds. (Springer,
NATO ASI
49, Berlin, 1997), pp. 653-678 [publisher's information].
12. I. Shimada et al., World Archaeol. 22, 247 (1991).
13. A. Kolata et al., Antiquity 74, 424 (2000).
14. M. Brenner et al., in Interhemispheric Climate Linkages, V.
Markgraf,Ed. (Academic Press, New York, 2001), pp. 87-103
[publisher's
information].
15. J. S. Dean et al., in Themes in Southwest Prehistory, G. J.
Gumerman, Ed. (Schl. Amer. Res. Press, Santa Fe, 1993), pp. 53-86
[publisher's information].
16. www.grida.no/climate/ipcc/regional
17. The leaked Summary for Policy Makers of the upcoming Third
Assessment Report by the IPCC gives estimates of 1.5=B0 to
6.0=B0C.=20
18. H.W.'s research was supported by the National Endowment for
the
Humanities, NSF, Malcolm H. Wiener Foundation, Leon Levy, Raymond
Sackler, and Yale University, and R.S.B.'s research was supported
by the
NSF and the U.S. Department of Energy. We thank H. F. Diaz, M. K.
Hughes, M. Moseley, and E. J. and D. S. Bradley for comments.
H. Weiss is at the Departments of Anthropology and Near Eastern
Languages
and Civilizations, Yale University, New Haven, CT 06520, USA.
E-mail:
harvey.weiss@yale.edu.
R. S. Bradley is at the Department of Geosciences,
University of Massachusetts, Amherst, MA 01003, USA. E-mail:
rbradley@geo.umass.edu
Copyright 2001, AAAS
=========
(3) SEEDS OF LIFE MAY HAVE REACHED EARTH ON A COMET
From The Independent, 30 January 2001
http://www.independent.co.uk/news/UK/Science/2001-01/comet300101.shtml
By Steve Connor, Science Editor
30 January 2001
Powerful evidence that life on Earth originated in outer space is
published
today by scientists who have created the biological building
blocks of
living organisms in a laboratory designed to mimic interstellar
dust clouds.
The findings support the belief that life originated with the
help of
complex organic molecules that rained down on Earth from comets
and other
cosmic debris.
Scientists from the Ames Research Center near San Francisco, part
of the US
National Aeronautics and Space Administration, and the University
of
California at Santa Cruz claim they not only generated complex
molecules,
but the compounds organised themselves into cell-like
"vesicles" on contact
with water.
The researchers' equipment was designed to replicate the
conditions of
interstellar dust clouds such asthe Eagle Nebula photographed by
the Hubble
space telescope, where temperatures can reach near absolute zero
(minus
273C).
The researchers added simple molecules such as ammonia, carbon
monoxide and
dioxide, and methanol to a mixture of fine ice particles trapped
in a
vacuum. When they irradiated the mixture with ultraviolet light,
they found
to their surprise that complex organic molecules were created.
The molecules
"self assembled" as aggregates of circular vesicles,
reminiscent of a living
cell's outer membrane.
Lou Allamondola, the team's leader, said the aim of the study was
to find
out what sort of compounds Nasa might expect to find in comets
and other
planetary bodies, which would help the agency in future space
missions. "We
expected ultraviolet radiation would make a few molecules that
might have
some biological interest, but nothing major," he said.
"Instead, we found that this process transforms some of the
simple chemicals
that are very common in space into larger molecules which behave
in far more
complex ways, which many people think are critical to the origin
of life."
The findings, published in the Proceedings of the National
Academy of
Sciences, surprised the scientists in the degree to which the
environment of
an interstellar dust cloud complex was hospitable to the creation
of organic
material. Scott Sandford, a member of the research team, said:
"Instead of
finding a handful of molecules only slightly more complicated
than the
starting compounds, hundreds of new compounds are produced in
every mixed
ice we have studied. We are finding that the types of compounds
produced in
these ices are strikingly similar to many of those brought to
Earth today by
falling meteor-ites and their smaller cousins, the interstellar
dust
particles."
Equally surprising was the finding that some of those complex
molecules
possessed properties that were important to life, such as the
ability to
form a membrane enclosing a "bag" of biological
chemicals.
Dave Deamer, professor of chemistry at the University of
California at Santa
Cruz, said the microscopic vesicles created by the molecules in
the presence
of water resembled living cells with membranes. "All life
today is cellular,
and cells are defined by membranes that separate the [inside]
cytoplasm from
the outside world," he said. "When life began, at some
point it became
compartmented in the form of cells. But where did the first cell
membranes
come from?"
Several lines of evidence point towards space being an important
generator
of life's complex building blocks. Scientists have found that the
three-dimensional structures of organic molecules in comets tend
to be a
"left-handed" form similar to those on Earth.
Otherscientists have found the window of opportunity for life to
begin has
narrowed. Research has shown that the early Earth was bombarded
with
life-destroying comets much later in its history than was
realised. Yet the
earliest signs of life are being pushed further back towards the
planet's
origins some 4.5 billion years ago.
This supports the view of Sir Fred Hoyle, the British cosmologist
who
proposed in the 1960s that life on Earth could have been
"seeded"
bybiological molecules fromouter space. His ideas were ridiculed
at the
time.
Copyright 2001, The Independent
==========
(4) WITHOUT JUPITER, HOME ALONE
From NASA Astrobiology Institute, 29 January 2001
http://nai.arc.nasa.gov/index.cfm?page=homealone
To a biologist, the ingredients needed to form life include
water, heat and
organic chemicals. But some in the astrophysics and astronomy
community
argue that life, at least advanced life, may require an
additional
component: a Jupiter-sized planet in the solar neighborhood.
"A long-period Jupiter may be a prerequisite for advanced
life," said Dr.
Alan Boss, a researcher in planetary formation. Boss, who works
at the
Carnegie Institution of Washington, is a member of the NASA
Astrobiology
Institute (NAI).
In our own solar system, Jupiter, with its enormous gravitational
field,
plays an important protective role. By deflecting comets and
asteroids that
might otherwise hit Earth, Jupiter has helped to create a more
stable
environment for life to evolve here. It's generally believed that
a massive
impact was responsible 65 million years ago for wiping out
dinosaurs on
Earth. If not for Jupiter, it's possible that many other such
impacts would
have occurred throughout Earth's history, preventing advanced
life from ever
gaining a foothold.
Jupiter is significant not only for its size but also for its
location in
our solar system, far from the Sun. Because it orbits at slightly
more than
5 AU (astronomical units-the distance between the Earth and the
Sun is 1
AU), there is plenty of room in the inner part of our Solar
System to
accommodate a range of smaller planets.
Within the inner solar system there exists a region, known as the
habitable
zone, where liquid water, and therefore life, can potentially
exist on a
planet's surface. Without liquid water, life as we know it is not
possible.
The habitable zone around our Sun stretches roughly from the
orbit of Venus
to the orbit of Mars. Venus is generally believed to be too hot
to support
life. Earth, it appears, is just right. And the jury is still out
on Mars.
Understanding the role that Jupiter plays in our own Solar System
helps
astronomers focus their search for habitable planets around other
stars.
"If," Boss explains, "a Jupiter-mass planet on a
stable, circular orbit
[around another star at] around 4 to 5 AU was found, without any
evidence
for other gas giant planets with shorter period orbits, such a
discovery
would be like a neon light in the cosmos pointed toward that
star, saying
'Look here!'. That star would be a prime target for looking for a
habitable,
Earth-like planet."
But to date, no such planetary systems have been found orbiting
distant
stars. That's due in large part to the technique used by
astronomers to
search for extrasolar planets. The technique that has been used
to locate
most of the 59 known extrasolar planets is called radial velocity
or Doppler
spectroscopy. It is based not on observing a distant planet
directly, but by
observing the effect that the planet's gravity has on the motion
of the star
it orbits.
As a giant planet moves around a star, its gravity pulls the star
first one
way, then the other. "Strictly speaking, Copernicus had it
wrong," said
Boss. "Planets don't move around their stars; they actually
move around the
center of mass of the planetary system, and so does the
star." This motion
of the star is detectable from Earth as a minute periodic shift
in the color
of the star's light.
When a clear pattern emerges in this color shift over a number of
orbits of
the planet around the star, astronomers are confident that they
have
detected a giant extrasolar planet. "We can infer the
presence of planets
indirectly by observing the wobble of a star in space caused by
its motion
around the center of the system," said Boss. By studying
this wobble pattern
in detail, they can determine a minimum mass for the planet, its
distance
from the star and the shape of its orbit.
To date, however, nearly all of the giant planets found have been
much
closer to their stars than Jupiter is to the Sun. None of the
extrasolar
Jupiters discovered so far orbits with a period large enough to
encourage
the formation of a habitable Earth-mass planet. Astronomers
believe that
this is probably an effect of the radial velocity search
technique, not
necessarily an indication of what's actually out there. Because
closer-in
planets orbit their stars more frequently, it takes less time for
an
Earthbound observer to see a pattern emerge in its star's wobble
than it
would for a planet farther out, with a longer orbital period.
One shouldn't conclude, however, that Solar-System-like
configurations are
rare-indeed, such systems could still be quite commonplace. We
just haven't
found them yet. Jupiter, for example, takes 12 years to orbit the
Sun. To
firmly identify a similar-sized planet at a similar distance from
another
star would require a minimum of 24 years, or two full orbits.
Boss points out that "several planet search programs have
been in action
since 1987. Their accuracy has increased significantly in the
last five
years, so we can expect that long-period Jupiters will be found
by these
programs in the coming years-it is just a matter of a few more
years before
astronomers should start to find them. So stay tuned!"
What Next?
Future projects for the discovery of extrasolar worlds include
NASA's Space
Interferometry Mission, due to be launched in 2005. This
space-based
telescope will be better able to detect the motions of distant
stars. In
2011, NASA hopes to launch the Terrestrial Planet Finder, which
would search
for light reflecting off of distant planets, including planets as
small as
Earth. This space-based telescope would be able to also determine
a planet's
temperature and the composition of its atmosphere.
Copyright 2001, NASA
===========
(5) ONLY SOLAR SYSTEMS WITH JUPITERS MAY HABOUR LIFE
From Andrew Yee <ayee@nova.astro.utoronto.ca>
News Services
University of Arizona
Tucson, Arizona
Contact Information:
Jonathan I. Lunine, 520-621-2789, jlunine@lpl.arizona.edu
Jan 29, 2001
Only Solar Systems with Jupiters May Harbor Life, UA Scientist
Says
By Lori Stiles
The search for Earth-like life on other worlds should focus on
solar systems
with Jupiter-like planets, a University of Arizona scientist
reports today
in the Jan. 30th issue of the Proceedings of the National Academy
of
Sciences.
Jupiter-like planets flinging Mars-sized objects toward their
sun-like stars
would deliver the water needed for carbon-based terrestrial life,
said
Professor Jonathan I. Lunine of the Lunar and Planetary
Laboratory, chair of
the UA Theoretical Astrophysics Program.
That, evidence says, is what happened in our solar system, Lunine
concludes.
"The bottom line is, the asteroid belt certainly had much
more material when
the solar system was forming than it does today, and Jupiter was
responsible
for clearing most of that material out," he said.
As the solar system formed, Jupiter's powerful gravity perturbed
asteroids
to accrete into larger and larger objects -- terrestrial
"embyros" as big as
Mars or bigger -- then tossed them into very unstable elliptical
orbits.
Those that hit Earth when flung toward the inner solar system
delivered the
water that now fills Earth's oceans. That happened when Earth was
about half
its present size.
Lunine and Italian and French colleagues published in the
November 2000
Meteoritics and Planetary Science their model of how planetary
embryos
supplied most of the Earth's ocean water. Authors on the article
are
Alessandro Morbidelli and Jean Petit of the Observatory de la
Cote d'Azur,
John Chambers of NASA Ames, Lunine of the UA, Francois Robert of
the Paris
Museum of Natural History, Giovanni Valsecchi of the Institute
for Space
Astrophysics (Rome), and Kim Cyr of NASA Johnson Space Center.
A solar system with water-bearing asteroids but no giant planets
might not
evolve habitable worlds with oceans, they conclude.
The deuterium-to-hydrogen ratio in Earth's seawater is the key
clue as to
the source of the oceans. Seawater contains 150 ppm deuterium, or
heavy
hydrogen. That's about five or six times the
deuterium-to-hydrogen ratio
found in the sun and in the solar nebula gas, known from
measurements made
at Jupiter. But it's only about a third of the
deuterium-to-hydrogen ratio
measured in comets Halley, Hyakutake, and Hale-Bopp,. The
findings
contradict the popular idea that comets supplied the Earth with
oceans.
"If deuterium abundances in the asteroid belt are correctly
reflected by the
meteorites, planetary embryos sent careening by Jupiter into the
Earth are
by far and away the biggest contribution to Earth's water,'"
Lunine said.
That Mars meteorites are richer in deuterium than Earth's
seawater is
consistent with the model. Lunine said. So is the scenario that
Earth's moon
was created when a Mars-sized object slammed into proto-Earth, an
idea
developed by UA planetary sciences Professor Jay Melosh and
others, Lunine
noted.
Astronomers in the past half decade have discovered that there
are more
planets outside our solar system than in it. They have found what
may be
giant gas planets at least as massive as Jupiter in orbit around
50 nearby
stars.
All of the newly found gas giants are closer to their stars than
Jupiter is
to the sun -- some as close to their parent stars as Mercury is
to the sun.
That giant gas planets exist in the inner solar system "has
enormous
implications for the frequency of habitable Earth-like planets in
the
galaxy," Lunine said.
The radial velocity observing technique used in the discoveries
reveals
planets by the Dopper effect of starlight. But the technique is
blind to
planets that may be farther out in their solar systems. Lunine
has found in
research he did with David Trilling of the University of
Pennsylvania and
Willy Benz, University of Bern, Switzerland, that for every giant
planet
detected close to a parent star, two or three giant planets orbit
farther
out, waiting to be discovered.
With no plausible theory of how objects more massive than Jupiter
can form
so close to their parent stars, theorists like Lunine have
modeled the
complicated story of how Jupiter-like planets might form far out
in the
solar system and migrate inward. The gist of the story is that
some planets
migrate all the way in and transfer all their mass to the sun and
disappear.
Others migrate only partway in before the gaseous disk
disappears, at which
time inward migration stops and terrestrial planets form from
leftover rocky
debris.
Jupiter, at about 5 astronomical units (AU) from the sun, is well
beyond the
"habitable zone," the region where liquid water is
stable. (Earth is one
astronomical unit from the sun.)
"If giant planets existed closer to a star than 5 AU -- say,
at 3 AU --
there would still be terrestrial planets in stable orbits,"
Lunine said.
"But they could well be dry because the giant planet would
have tossed
water-bearing material away from the habitable zone."
Or, if the giant gas planet were very distant in the outer solar
system, it
likely would fling water bound in planetary embryos to a region
too cold for
life. And it would send too few water-bearing embryos in toward
terrestrial
planets at 1 AU, Lunine added.
"In that case, you might end up with a big but icy
terrestrial planet at 4
or 5 AU -- too cold to support life as we know it," he said.
Lunine is a member of a key project for a future space astrometry
mission
called SIM.
Astrometry, a technique that measures the motions of stars with
extreme
precision, will do a better job in finding Jupiter-like planets
that are
moderately distant from their parent stars than does the radial
velocity
technique. Astrometry will also give actual rather than minimum
planet
masses, unlike the radial velocity method.
Direct imaging is the ultimate technique for planet searches,
however,
because the spectra, or colors of light, from a planet reveal
planetary
atmospheres and history.
The UA-led Large Binocular Telescope consortium, the
California-led Keck
Telescope consortium, and Europe's impressive national giant
telescopes are
developing adaptive optics for the direct detection of
extra-solar planets.
Future space-based, very long baseline interferometers called
Terrestrial
Planet Finder and Darwin promise to be more powerful tools in
planet
searches.
"If you really want to discover another Earth, you've got to
understand
where the Jupiters are and what they've done to their solar
systems over
time," Lunine said. "You might find water vapor in the
atmosphere of that
second Earth, but you don't know if that water vapor is supported
by an
ocean that is a kilometer, 10 kilometers or 5 meters deep."
Lunine recently argued the case at a workshop for participants in
the
Terrestrial Planet Finder (TPF) project. UA collaborates with
Lockheed
Martin to develop a winning design for TPF, a space observatory
that NASA
plans to launch in 2012 as part of Origins Program.
Lunine and other UA scientists working on TPF, including Nick
Woolf and
Roger Angel of Steward Observatory, propose a precursor project
to TPF for
direct mapping of Jupiter-like planets.
[NOTE: Images supporting this release are available at
http://uanews.opi.arizona.edu/cgi-bin/WebObjects/UANews.woa/wa/SRStoryDetails?ArticleID=2942
]
===========
(6) GENESIS FACTOR: THE TRANSCRIPTS
From Michael Paine [mailto: mpaine@tpgi.com.au
]
Dear Benny,
The transcripts and Real Time audio of The Genesis Factor by Paul
Davies are
now available at:
http://www.abc.net.au/rn/science/ss/index/index.htm
http://www.abc.net.au/rn/science/ss/stories/s223723.htm
http://www.abc.net.au/rn/science/ss/stories/s223724.htm
http://www.abc.net.au/rn/science/ss/audio/sss13012001.ram
http://www.abc.net.au/rn/science/ss/audio/sss20012001.ram
It covers the origin of life and the possibility of exchange of
life between
plants and star systems.
regards
Michael Paine
===========
(7) JAPANESE RESEARCHERS PREPARE LAUNCH OF CUBIC SATELLIYES TO
OBSERVE
LEONIDS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
[ http://www.yomiuri.co.jp/newse/20010130wo72.htm
]
Tuesday, January 30, 2001
Young researchers prepare to launch cubic satellites
By Satoshi Yamada, Yomiuri Shimbun Staff Writer
Three small satellites, each designed and developed by Japanese
university
students, will be launched into space over a one-year period
beginning in
autumn.
The satellites are part of a project set up by Tohoku University
in Miyagi
Prefecture, Tokyo University and Tokyo Institute of Technology to
nurture
younger researchers through practical experiments -- in this case
by
observing the Leonid meteor shower.
In light of the launch failures that have marred Japan's space
program in
the past, the satellites will be placed in orbit aboard rockets
launched by
foreign countries. The universities are raising technical and
financial
support for the launches from relevant companies in order to help
enhance
interests among Japan's young researchers.
One of the student research teams, led by Tohoku University and
the
Institute of Space and Astronomical Science and monitored by the
Education,
Science and Technology Ministry plans to launch a satellite to
monitor the
next major Leonid meteor shower, which will occur over North
America in
November 2002. The satellite was designed in 1999 by a team of
university
students led by Hiroshi Hamano, who at the time was a senior and
is now
pursuing a graduate degree. The team's design received the Idea
Award at the
1999 Satellite Design Contest, which is considered a major career
boost for
young researchers eyeing careers in the satellite industry.
Hajime Yano, an assistant researcher at the the Institute of
Space and
Astronautical Science who is involved in the project, praised the
team's
design. "The idea to directly observe the impact of meteor
showers on the
Earth is unique," he said. Yano is a veteran of a U.S.
National Aeronautics
and Space Administration project to observe meteor showers from
an airplane.
The Leonids are seen at an altitude of about 200 kilometers,
higher than
most meteor streams, and are thus monitored more clearly from
satellites on
the orbit 300 kilometers above the Earth than from the ground.
According to Yano, detailed photographs of the Leonids will
enable
researchers to observe meteorites more easily before they hit the
Earth's
surface.
The team has come up with a 50-centimeter-long cubic satellite
that weighs
about 50 kilograms and is equipped with several types of digital
cameras
that can capture a variety of light rays. The satellite will be
"piggy-backed" into space on a U.S. or Russian rocket
before August 2002.
The project created by the university students has attracted
attention
internationally, and the research team is considering the
participation of
11 organizations in eight countries such as the United States and
Britain in
the project by receiving data. "When I first heard that our
satellite will
be really launched, I became afraid that we could not complete
it," Hamano
said.
Tohoku University's Assistant Prof. Kazuya Yoshida said,
"The project as an
experience-oriented education in space engineering is a golden
opportunity
for students. We want to invite participation in the project
without the
framework of universities."
===
'Dice' satellites
Meanwhile, two "dice" satellites developed by Tokyo
University and Tokyo
Institute of Technology will be launched in November at Baikonur
space
station in Kazakhstan. The satellites, which are made of
10-centimeter
square panels weighing about one kilogram each, will be launched
with
assistance from the Japan-U.S. University Space Systems
Symposium, which
comprises university and space-related organizations from the two
countries.
The Russian rocket Dnieper will place the two Japanese
satellites, along
with 16 other satellites, into orbit about 400 kilometers above
the Earth's
surface. The two satellites will be the first satellites made by
Japanese
university students to be launched into space.
Tokyo University will use its XI-1 satellite to test
communication equipment
and solar battery function, while Tokyo Institute of Technology
will be
running tests on its own communications equipment.
More than 10 students took part in the XI-1 project, from initial
design to
assembly. "For students, practical experience is very
precious. They should
take advantage of the opportunity to learn systematic
procedures," said
Tokyo University Assistant Prof. Shinichi Nakasuka, who advised
the team.
"In three years, I want to develop the original satellite
into a new,
high-performance one."
Copyright 2001 The Yomiuri Shimbun
==========
(8) FIRST SPACE WAR GAME ALARMS PENTAGON
From The Daily Telegraph, 30 January 2001
http://www.telegraph.co.uk/et?ac=000579381554028&rtmo=VkZuxZwx&atmo=99999999
&pg=/et/01/1/30/wswar30.html
By Ben Fenton in Washington
THE Pentagon has held its first war games in space and discovered
that it
could be vulnerable to a serious defeat, military planners said
yesterday.
The five-day exercise, aimed at finding out how to defend
America's
satellites and destroy those of a potential enemy, is thought to
have had
alarming results. Set in 2017, the deadly serious game - acted
out in
Colorado - involved two countries, codenamed Red and Blue, but
obviously
representing China and the United States.
Maj Gen William Looney III, commander of US air force space
operations,
said: "We don't normally play space. The purpose of this
game was to focus
on how we really would act in space."
The military has been reluctant to talk about the results of the
war game,
but it is believed both sides used "cyberattacks" -
efforts to disable each
other's mainframe computers. The "Chinese" side also
tried a pre-emptive
strike by buying up all the commercial satellites it could find,
blocking a
vital source of support that the Pentagon has come to rely on.
Unexpected side-effects of the war game are thought to have
included the new
tactic of hijacking an opponent's satellites and using it to
broadcast
propaganda.
Copyright 2001, The Daily Telegraph
=============================
* LETTERS TO THE MODERATOR *
=============================
(9) PLUTO: WHY WE SHOULD LEAVE THINGS AS THEY ARE
From David H. Levy <david@jarnac.org>
Dear Benny,
You countered my so-called political arguments with political
arguments of
your own! Actually, had you been a part of the interview process
for the AP
article, or had you bothered to check any of my articles on the
subject, you
would not so quickly dismiss my argument.
Yes, I knew Clyde Tombaugh and admired him, and yes, I knew how
unhappy this
debate made his last years. However, both he and I subscribed to
the
definition of a planet that states that if the body (that orbits
the Sun
directly, and is not a moon) is big enough to condense
granavitionally to
form a sphere, then it's a planet. If not, it's a minor planet or
an
asteroid. It's a simple and natural definiition. If
we want to bring Ceres
back into the world of major planets, that is also fine.
Additionally, there is something to be said for history-- Pluto
has been
considered a major planet for three generations, not the year or
so that
Ceres was historically called a major planet. I believe that
until we land
on Pluto and find incontrovertible evidence that that world does
not wish to
be called a planet, that we should leave things as they are.
Sincerely
David H. Levy
============
(10) IS PLUTO A PLANET?
From Frankfurter Allgemeine Zeitung, 2 January 2001
http://www.badastronomy.com/zeitung/index.html
A Ball of Frozen Gases
By Phil Plait
GREENBELT. This might seem like an odd question. Of course, it's
a planet.
It was discovered in 1930, and we have been calling it a planet
for more
than 70 years. It's big, and it orbits the sun, so it must be a
planet.
Right?
Not necessarily. There was a heated debate recently over just
what to call
Pluto -- a major planet like Jupiter or the Earth or a minor
planet or
smaller object like an asteroid or giant comet. Though the debate
has died
down somewhat, astronomers still discuss the issue. To an
outsider, the
argument might seem to be about semantics. But to an astronomer,
a name has
a deeper meaning. It is a clue to the behavior of an object and
perhaps to
its origin. In addition, astronomers are people, and most of them
are fond
of Pluto and think it should be called a planet.
There are many reasons to debate Pluto's status. For one thing,
Pluto is
weird by anyone's definition. With a radius of 1,130 kilometers
(700 miles),
it is by far the smallest planet. Mercury, the next smallest, is
more than
twice the diameter of Pluto and has 10 times the volume. Our own
moon, which
is in fact small compared to moons of other planets, is 50
percent larger
than Pluto.
Pluto has a moon, named Charon, which is very large compared to
Pluto
itself. Charon is roughly half as big as Pluto, which is the
largest ratio
of moon to planet size in the solar system. Our own moon holds
second place,
with a radius only one-fourth that of the Earth. Pluto appears to
be a ball
of frozen gases, the least dense of the "solid" planets
and more like a moon
of the outer planets than a planet itself.
Perhaps most peculiar is Pluto's orbit. It crosses Neptune's,
bringing it
closer to the sun than Neptune for 20 years out of its 250-year
orbit. There
is no chance of a collision, though. Pluto's orbit takes almost
exactly one
and a half times that of Neptune's, so that whenever Pluto is
nearest to
Neptune's orbit, Neptune is always on the other side of the Sun.
If Pluto's
orbit were changed even slightly, it would eventually have a
close encounter
with Neptune, which would either fling it out of the solar system
or plunge
it toward the sun, where it would collide with Jupiter and be
ejected from
the solar system. Either way, an object near Neptune that does
not have the
type of orbit Pluto does would be quickly lost.
Astronomers now think that Pluto might have been the largest
member of a
family of objects, most of which were not in fixed orbits and
were tossed
out of the solar system. These objects are actually a subset of a
vastly
larger collection of icy bodies recently proved to exist beyond
Pluto's
orbit. Pluto might simply be the biggest chunk of ice out of a
gang of
millions or billions of such chunks.
Worse, in October 2000, astronomers announced they had found a
fairly big
object with an estimated diameter of roughly one-fourth that of
Pluto's. A
month later, another object was found that might be as large as
half Pluto's
size and bigger than the largest asteroid, Ceres. It is quite
possible that
there are objects even farther out that are even bigger than
Pluto.
These objects erode at the argument for calling Pluto a true
planet. If it
is really just the biggest example of a group of supercomets,
then perhaps
its status as a planet should be in doubt. At the heart of the
debate is our
very definition of the word "planet." Currently, there
isn't one. The
International Astronomical Union (IAU), a worldwide body of
astronomers, is
the official keeper of names. It has no strict definition of a
planet, but
has decreed that there are nine major planets, including Pluto.
This, however, is not very satisfying. If the IAU doesn't really
know what a
planet is, how can it know there are nine? Perhaps confusing the
issue was
the idea to give Pluto dual status as a major and a minor planet.
This
thought has its merits, but in the end was turned down by the
IAU. For the
time being, Pluto remains simply a planet.
Fanning the fire, a paper has been released by two planetary
astronomers,
Alan Stern and Hal Levison, both from the Southwest Research
Institute in
the United States. They have worked out a logical scheme on
dividing objects
into major and minor planets.
By their new definitions, there are eight major planets in the
solar system
together with a large number of minor planets, of which Pluto and
Ceres are
the largest of the latter. This plan might appease everyone,
except for the
holdouts who still want Pluto to be considered a major planet.
Clearly,
Stern and Levison think Pluto is a minor planet. Levison once
said, "I
firmly believe that if Pluto were discovered today, we wouldn't
be calling
it a planet." Given the number and size of objects being
found today, he
might very well be correct. After all, Ceres was thought to be a
planet when
it was first discovered in 1801, but was downgraded to an
asteroid when
several more objects like it were found.
As for myself, I might be an astronomer, but I'm human, too. I
have seen
every planet in the solar system with my own eyes except for
tiny, distant,
frigid Pluto. If it were reclassified as a minor planet or just
another icy
object, then my roster would suddenly be complete, and I will
have seen
every major planet in the solar system.
Phil Plait is an astronomer at NASA's Goddard Space Flight Center
in
Greenbelt, Maryland, but is perhaps best known for his Web site
www.badastronomy.comJan.
1, 2001
© Frankfurter Allgemeine Zeitung 2000
The paper by Alan Stern and Hal Levison can be accessed at
http://www.boulder.swri.edu/alan/papers.html
============
(11) CAN 'REAL PLANETS' COLLIDE?
From Gerrit Verschuur <GVERSCHR@LATTE.MEMPHIS.EDU>
Would a real planet be in an orbit that crossed that of another
real planet?
Surely we should give some consideration to our definition of a
planetary
system - one in which the objects at the very least do not run
the risk of
collision because orbits intersect, even if at present they are
not quite
planar.
Gerrit Verschuur
============
(12) HOW THE NEW PLUTO DEBATE EVOLVED
From Kelly Beatty <kbeatty@skypub.com>
Benny...
At 11:59 AM 1/29/01 -0000, you wrote:
>After almost two years of silence, the notorious Pluto debate
is back in
full swing:...
Tyson's decision to exclude Pluto was certainly noted at the time
of the
Rose Center's opening early last year. (I guess this proves that
a story
really isn't news until it's issued as a NASA press release or
covered by
the New York Times.) Another salvo was fired last August, when
Brian Marsden
called for a vote on the matter among those attending a Kuiper
Belt session
at the IAU meeting. A check of your archives shows no reference
to that
event, but the curious can find it in our archive of IAU stories
at
http://www.skypub.com/news/000817_iau.html
Kelly Beatty
SKY & TELESCOPE
---------------
From the Sky & Telescope archive, 14 August 2000
http://www.skypub.com/news/000817_iau.html
Last year, when the International Astronomical Union's higher-ups
interceded
in a testy debate over the status of Pluto and declared the
far-flung world
to be a planet, not everyone was pleased. Brian A. Marsden, who
heads the
IAU's Minor Planet Center, had argued that Pluto should be
considered both a
major planet and a minor planet - and he still feels that way. On
August
11th, during the IAU meeting being held in Manchester, England,
Marsden
informally polled a group of roughly 100 planetary scientists to
ask whether
Pluto should be classified as a regular planet, a trans-Neptunian
object, or
both. (TNOs are icy bodies that populate the solar system beyond
Neptune's
orbit. Currently more than 300 of them have been discovered, most
of them a
few hundred kilometers across.) The vast majority of the audience
voted for
dual citizenship.
During the presentation that preceded Marsden's vote, Michael
A'Hearn
(University of Maryland) had compared Pluto's situation to that
of the
equally mysterious fossil Archeaopteryx - a bird according to
some
paleontologists, but a dinosaur according to others. "A dual
classification
is a practical way to deal with boundary cases" like Pluto,
says A'Hearn.
However, that won't happen any time soon. In early 1999 IAU
General
Secretary Johannes Andersen announced that the IAU considers
Pluto a planet,
period. Moreover, the MPC does not yet have a separate scheme for
classifying TNOs; they continue to receive designations as
asteroids. Pluto
expert Alan Stern (Southwest Research Institute) is among those
who oppose
dual classification. He says the planet-versus-TNO debate is
ill-posed:
"It's like asking whether Mike A'Hearn is a human being or a
North American.
One has to do with [origin], the other with location."
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