PLEASE NOTE:


*

CCNet, 29 Sepetmber 1999
------------------------


     POEM OF THE DAY

     The Shifting Earth

     By Malcolm Miller <stellar2@actonline.com.au>
    
     The world looks flat to most of us, and as well we think
     that it's unchanging, too, its familiar features and its climate
     there forever in the people's memory.  The rocks, the rivers,
     mountains and seas unchanged since 'time immemorial',
     ordained by God to be for evermore to be our home.
     'Not so' these upstart scientists say, the ancient shorelines
     and retreating glaciers only a small part of those clear signs
     laid out for us to read.Faith in the constancy of Earth is natural,
     but those who've learned to see and understand the unambiguous
     book of nature now know we live on shifting ground.
     As our numbers grow our vulnerability increases,
     so earthquake, ice, impact and flood will target more of us,
     unless we learn to develop survival skills to ensure our footing
     on this impermanent surface of a rocky sphere, with strategies
     to minimise the harm from shaking ground or flaming skies.

     MM 29.9.99


(1) HAS EARTH BEEN WATERY PLANET RIGHT FROM THE START?
    Andrew Yee <ayee@nova.astro.utoronto.ca>

(2) INTERPLANETARY EVOLUTION OF HUMAN CULTURE & COMMUNICATION
    Larry Klaes <lklaes@bbn.com>

(3) ANOTHER ICE-MAKING MACHINE IN THE SOLAR SYSTEM?
    ESA <sciweb@estec.esa.nl>

(4) NEW PLANET OR NEW KBO?
    BBC News Online, 28 September 1999


================
(1) HAS EARTH BEEN WATERY PLANET RIGHT FROM THE START?

From Andrew Yee <ayee@nova.astro.utoronto.ca>

[http://helix.nature.com/nsu/990930/990930-4.html]

Monday, September 27, 1999

Water bath
By PHILIP BALL

Prevailing opinion has it that the oceans came from space after the
Earth was formed 4.6 billion years ago. It has been thought that the
impact of icy bodies -- comets or debris left over from the formation
of the planets -- on the early Earth deposited the water that now fills
the ocean basins. But an alternative idea is that the material that
went into the formation of our planet was already wet.

All the planets formed from clumps of matter that condensed within the
cloud of gas and dust surrounding the new-born Sun. Collisions between
these clumps were constantly happening throughout the early Solar
System, and the debris that resulted then stuck together under its own
gravity. The lumps within the inner Solar System may have been dry and
rocky, with the volatile constituents -- the gases and liquids in the
atmospheres of Venus, Earth and Mars -- added by later collisions.

But did it have to be this way, or could the initial clumps have
themselves contained water? If so, it seems likely that most of this
water would have been dissolved in a pole-to-pole ocean of molten rock
-- magma -- when the Earth was still young. Such a magma ocean is
expected to have resulted from the massive collision widely believed to
have split off the material that formed the Moon. As the magma cooled
and froze, the water would then have come steaming out into the
atmosphere, later to condense into oceans.

As the Earth cooled, it separated into an iron-rich core and a rocky
mantle -- like slag separating from the molten metal in an iron
smelting furnace. Other metals similar to iron, such as cobalt, nickel
and tungsten, would have dissolved to different extents in the magma
ocean and the molten iron below. Geophysicists can account for the
known distribution of such metals between the present core and mantle
based on the way that they partition between iron and molten, dry rock
-- but how would water affect this picture?

Kevin Righter and Michael Drake from the University of Arizona have now
measured this partitioning behaviour, with water present, at the high
temperatures and pressures appropriate to the juncture between an iron
core and a magma ocean. They find that small amounts of water, as
postulated for a "wet" accretion of the Earth, do not undermine the
existing explanation for the distribution of metals between core and
mantle.

What is more, they say, water present from the very beginning of
Earth's history can help to explain why there is so much iron oxide in
the mantle today: the oxide is formed by the reaction of water with hot
iron. It is not easy otherwise to account for how the iron oxide got
there.

So the new measurements, reported in the journal Earth and Planetary
Science Letters (September), lend support to the idea that the Earth
has been a watery planet right from the start.

© Macmillan Magazines Ltd 1999 - NATURE NEWS SERVICE

=================
(2) INTERPLANETARY EVOLUTION OF HUMAN CULTURE & COMMUNICATION

From Larry Klaes <lklaes@bbn.com>

INTERPLANETARY INTERNET RESEARCH SEMINAR
Friday, 12 November 1999
09:00 - 12:15
Van Munching Hall, Marriott Room
University of Maryland, College Park

For travel directions to Van Munching Hall, please follow this link:
http://www.inform.umd.edu/CampusInfo/Facilities/Buildings/VMH/
Cost: approx. $16 at the door

Over the last thirty years, the terrestrial Internet has grown from a
few computers that were networked in a prototype laboratory environment
into a vast deployed system that is an indispensable component of the
present and future global economy. Key to its exponential growth has
been its underpinning of flexible and "open" standard communications
protocols (the TCP/IP suite) that permit diverse applications to
instantaneously exchange information. During the coming thirty years,
the terrestrial Internet will experience growth and evolution in ways
which are almost unimaginable. Its communications infrastructure will
experience huge increases in capacity, while a large varied of
"untethered", wireless-based applications will emerge as plug-ins to
the edges of its fiber/copper communications backbone. In the process,
the Internet's communications protocols will evolve to meet new
challenges.

The next thirty years will also see the need to expand the Internet so
that it can serve the communications needs of the progressive expansion
of human intelligence into space. The "InterPlaNetary Internet"
initiative has therefore been initiated by DARPA and NASA to chart a
course whereby the Internet may move gracefully off-planet.  The
purpose of this seminar is to introduce a candidate InterPlanetary
Internet (IPN) architecture to the research community and to solicit
feedback with respect to its unique challenges. To facilitate the
establishment of an interactive dialog with (and within) the community,
the candidate architecture will be presented as a whole, followed by
discussion focused in four key areas, each punctuated by opportunities
for questions and discussion. The preliminary agenda for this seminar
is presented below:

For further information, please contact:
M. Scott Corson
(corson@isr.umd.edu)
301-405-6630
Center for Satellite and Hybrid Communication Networks
Institute for Systems Research
University of Maryland, College Park
     
==================
ANOTHER ICE-MAKING MACHINE IN THE SOLAR SYSTEM?

From ESA <sciweb@estec.esa.nl>

http://sci.esa.int/newsitem.cfm?TypeID=1&ContentID=6891&Storytype=18

Uranus and Neptune are very different from Jupiter and Saturn,
according to examinations of the giant planets by ESA's infrared space
telescope, ISO. Jupiter and Saturn are mainly balls of gas but the more
distant Uranus and Neptune contain relatively large cores of ice. This
difference is confirmed by French and German astronomers who used ISO
to measure heavy hydrogen in the planet's atmospheres. Although the
result fits well with current ideas about planetary origins, it casts
doubt on the part played by comets.

Water ice and other types of ices, including methane, were a raw
material during the birth of the giant planets. Little of it survived
close to the Sun, where the Earth and other rocky planets formed. In 
cooler regions the ices supposedly made quite large planets, with
gravity strong enough to bind gases into the thick atmospheres that
make them giants. The accompanying picture from Stockholm University
illustrates a theoretical study of the building of a giant planet in
the young Solar System.

Although ISO could not see the icy cores, now hidden deep inside the
giant planets, it found a fingerprint of ice - an excess of heavy atoms
in the hydrogen gas of their atmospheres. Due to chemical reactions at
low temperatures ices possess an excess of heavy hydrogen, or
deuterium. Some of this deuterium has found its way into the
atmospheres of the planets,  where ISO's short wavelength spectrometer
(SWS) detected it.

"We have the first accurate values of deuterium's abundance in Uranus
and Neptune," says Helmut Feuchtgruber of Garching, Germany. "And we
can compare them with those in Jupiter and Saturn, obtained with the
same instrument. This enables us to draw conclusions about the deep
interior of the giant planets, which are completely hidden from view".

Uranus and Neptune have three times more deuterium in their hydrogen
gas than Jupiter or Saturn. This is consistent with ices making up more
than half of their mass, whereas in Jupiter and Saturn ices represent a
much smaller part of the total - too small to make any noticeable
enrichment of the deuterium in the atmospheres. The four giant planets
may have started with similar icy cores, each roughly ten times the
mass of the Earth. The differences then arose from the availability of
gases to fill their atmospheres, with Jupiter gathering about forty
times more gas than Uranus or Neptune did.

The ISO results confirm in broad outline the present theories of
planetary formation, but they contradict a popular belief that the ice
came from comets like those still seen today. Comets are icy survivors
from the origin of the Solar System, so it might be easy to imagine
congregations of comets building the icy cores of the giant planets.
But the proportion of deuterium in comets is five times greater than in
Uranus or Neptune, and the ISO scientists calculate that the cores were
made from ice containing much less deuterium. So in the swirling cloud
of gas and dust around the Sun, from which the planets were born,
theorists have to imagine a different ice-making machine.

An extensive study of the outer planets, using ISO observations, is led
by Thèrese Encrenaz and Emmanuel Lellouch of the Observatoire de
Paris-Meudon and Helmut Feuchtgruber of the Max-Planck-Institut für
Extraterrestrische Physik. A full account of results so far has been
included in a new book from ESA, "The Universe as Seen by ISO"
(ESA SP-427).

A video clip on this story will be released at 13:00 UTC today, 29
September on Tracker 2000 - the multimedia service from ESA science
at: http://sci.esa.int/tracker2000/index.htm

The video can be ordered via an on-line form.

Footnote about ISO

The European Space Agency's infrared space telescope, ISO, operated
from November 1995 till May 1998, almost a year longer than expected.
As an unprecedented observatory for infrared astronomy, able to examine
cool and hidden places in the Universe, ISO successfully made nearly 30
000 scientific observations.

For more information please contact:
ESA Public Relations Division:
Tel: +33(0)1.53.69.71.55
Fax: +33(0)1.53.69.76.90

Martin F. Kessler (ISO Project Scientist):
Tel: +34 918131254
mkessler@iso.vilspa.esa.es

===================
(4) NEW PLANET OR NEW KBO?

From the BBC News Online, 28 September 1999
http://news.bbc.co.uk/hi/english/sci/tech/newsid_460000/460095.stm

Old spacecraft makes surprise discovery

By BBC News Online Science Editor Dr David Whitehouse

Scientists have discovered a new object orbiting the Sun after a
spaceprobe was mysteriously knocked off course.

Researchers have yet to identify the object, but they are confident
it exists because of the way it appears to have deflected the tiny
Pioneer 10 craft, which is hurtling out towards the stars.

If the observations are confirmed by other astronomers, it will be
only the second time in history that a Solar System object has been
discovered by its gravitational effect alone.

The first was the planet Neptune which was discovered in 1846. Its
position was predicted because of its gravitational tug on the planet
Uranus, which appeared to be behaving oddly following its discovery
59 years earlier.

The new body, found by a team at Queen Mary and Westfield College in
London, UK, and the Jet Propulsion Laboratory in California, is
probably a so-called Kuiper Belt object.

The astronomers looked at Pioneer 10's tracking data obtained with
the Nasa Deep Space Network, an array of large radio telescopes
designed to communicate with far-off space probes.

Rocky swarm

On 8 December, 1992, when Pioneer was 8.4 billion km (5.2 billion
miles) away, they saw that it had been deflected from its course for
about 25 days.

The scientists have been looking for such an effect for years and are
currently analysing the data using several different methods to
confirm their findings.

In a few weeks time, they are expected to be able to place an upper
limit on the mass of the object and make predictions about its
position. Early indications suggest it may be an object that is being
ejected from our Solar System after encountering a major planet.

"We are quite excited that we have found one of these events. It is a
very neat signal," Dr Giacomo Giampieri of Queen Mary and Westfield
College told BBC News Online.

If confirmed, it would be one of over 100 known icy and rocky objects
that circle the Sun at vast distances, mostly beyond the most distant
planet Pluto.

They are small in planetary terms, just a few hundred kilometres at
most, but astronomers believe there are millions of them swarming
around the Sun in a vast belt. The first one was detected in 1992.

Starbound probe

The Pioneer 10 spacecraft was launched in March 1972 and has lived up
to its name.

It was the first spacecraft to travel through the asteroid belt, the
ring of rocky debris that orbits the Sun between Mars and Jupiter.
Before it successfully traversed this region of space, scientists did
not know if a spacecraft could get through unharmed.

It was also the first craft to reach a gas-giant planet, Jupiter,
after which it left the solar system becoming the first craft to
effectively leave the Sun's planetary system, even though it has not
yet passed into interstellar space.

It is currently 11 billion km (6.8 billion miles) away and still
transmitting even though Nasa ceased monitoring its signals in 1997
after it had spent 25 years in space.

Earlier this year, scientists were puzzled by what was described as a
mysterious force acting on the probe. It led to speculation that
there was something wrong in our understanding of the force of
gravity.

Eventually the effect was tracked down to the probe itself, which was
unexpectedly pushing itself in one particular direction. Pioneer 10
will reach the stars of the constellation of Taurus in about two
million years.

Copyright 1999, BBC


----------------------------------------
THE CAMBRIDGE-CONFERENCE NETWORK (CCNet)
----------------------------------------
The CCNet is a scholarly electronic network. To subscribe/unsubscribe,
please contact the moderator Benny J Peiser <b.j.peiser@livjm.ac.uk>.
Information circulated on this network is for scholarly and
educational use only. The attached information may not be copied or
reproduced for any other purposes without prior permission of the
copyright holders. The fully indexed archive of the CCNet, from
February 1997 on, can be found at http://abob.libs.uga.edu/bobk/cccmenu.html



CCCMENU CCC for 1999

The content and opinions expressed on this Web page do not necessarily reflect the views of nor are they endorsed by the University of

The content and opinions expressed on this Web page do not necessarily reflect the views of nor are they endorsed by the University of Georgia or the University System of Georgia.