PLEASE NOTE:
*
CCNet DIGEST, 19 January 1999
-----------------------------
(1) NEAR UPDATE
Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
(2) AFTER 8000 YEARS, NOAH'S FLOOD MAKES HEADLINES AGAIN
NEW SCIENTIST, 16 January 1999, p. 43
(3) PLUTO MAY BE 'DEMOTED'
BBC News Online
http://news.bbc.co.uk:80/hi/english/sci/tech/newsid_257000/257360.stm
(4) 20-YEAR EARTH TEMPERATURE RECORD
NASA Science News
http://science.nasa.gov/newhome/headlines/essd12jan99_1.htm
(5) A TUNGUSKA-TYPE EVENT IN 1867?
Timo Niroma <timo.niroma@tilmari.pp.fi>
(6) THE SOLAR GAS RECORD IN LUNAR SAMPLES AND METEORITES
R. Wieler, ETH ZURICH
(7) IS THE SUN A SUN-LIKE STAR?
B. Gustafsson, ASTRONOMICAL OBSERVATORY
UPPSALA
(8) SPECIAL ISSUE: THE CASSINI/HUYGENS MISSION
PLANETARY AND SPACE SCIENCE, Vol.46 Iss.9-10
SEP-OCT 1998
====================
(1) NEAR UPDATE
From Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
NEAR Clean-Up Hydrazine Engine Burn Scheduled for Jan. 20
http://near.jhuapl.edu/news/flash/99jan15_1.html
A small hydrazine engine burn is scheduled for Jan. 20 at noon,
EST.
This burn is intended to fine-tune the spacecraft's trajectory by
approximately one degree and to increase its speed by 31 miles
per hour
(14 meters/second), allowing NEAR to gain on the faster-moving
Eros
asteroid. This trajectory correction maneuver was planned
following the
successful completion of the large bipropellant engine burn on
Jan. 3.
======================
(2) AFTER 8000 YEARS, NOAH'S FLOOD MAKES HEADLINES AGAIN
From NEW SCIENTIST, 16 January 1999, p. 43
GRAB YOUR WADERS?
Book Review: Noah's Flood by William Ryan and Walter Pitman,
Simon &
Schuster, $25, ISBN 0684810522
The sea is splashing round your ankles, and showering every sign
of
rising. What do you do if you are one of the first farmers who
settled on fertile plains by the sea shore? First wonder, then
worry,
then head for boats or the high ground, taking your essentials:
food
stores, animals, seeds and a granny or two. It would be something
you
would never forget, and your grandchildren would hear the Story
of
the Rising Sea many times.
Such stories, of a great flood and how it was survived, are
recorded
in the Bible and other ancient texts. But do these stories have
any
factual basis? in NOAH'S FLOOD, Bill Ryan and Walter Pitman set
out
to show that they do. There was a truly great flood around the
Black
Sea, recounted orally and eventually in writing by descendants of
the
scattered groups of survivors. Geology, climatology, archaeology,
linguistics, history and international subterfuge bordering on
espionage all play a part in a fascinating story that reveals as
much
about how science works today as it does about the world 7000
years
ago.
Ryan and Pitman are geologists; their interest in this area began
in
the early 1970s, at the time when the curious history of the
Mediterranean was first revealed. Around 6 million years ago,
this sea
had become a hot desert, with shallow lagoons so rich in mineral
salts that little could live there. The waters returned abruptly,
flooding back through the Straits of Gibraltar in less than a
century. This idea seemed strange at first, but the evidence
collected by Ryan, among others, was incontrovertible.
A chance remark from a colleague set Ryan and Pitman wondering
whether a similar catastrophic flood could have been witnessed
and
remembered as the story of Noah. Strands of evidence from diverse
fields slowly came together to implicate the Black Sea, around
5600
BC. The geography and climate were right for a spectacular
refilling
of this inland sea; people lived there and may have moved to, for
example, the Middle East, bringing their tales of a disastrous
flood
with them. The pieces finally began to fall into place with the
aid
of precise methods dating archaeological and climatological
records,
and, especially, a geophysical survey of the Black Sea.
Ryan and Pitman found the sea had shrunk and become a freshwater
lake, cut off from the oceans by a natural dam across the
Bosphorus.
The lake was surrounded by plains where, they presume, people
lived,
traded and may have been the first farmers. Eventually, the
world's
oceans rose again and the flood came, with the waters advancing
around a quarter of a mile inland each day for a year or two.
People
fled to start new lives elsewhere. These disparate groups are
thought
to be the ancestors of, among others, the Sumerians who handed
down
accounts of the great flood in Gilgamesh's tale.
The flood is a fascinating story, all the better for being told
by
working scientists. What comes across clearly is the thrill of
discovery: being on the boat when the drill core brings up
shallow
water sediments, from the floor of a deep sea, or seeing the
significance of observations made in the 19th century by intrepid
science-explorers. Parts of the book fling the reader almost too
far
into the world of these individual scientists, but they also
serve to
highlight the chances of the past century. Now collaboration
breeds
success: gone are the days of the lone wolf researcher, competent
in
every discipline.
But the scientific goal has not changed: all these researchers
want
to understand is the world, past and present. Ryan and Pitman's
book
is a mind-expanding read. The mixture of disciplines and ways of
doing science is exhilarating and paints a realistic picture of
the
way research works. It makes you really wonder if similar hard
science might lie behind other folk-tales around the world.
Sue Bowler edits the Royal Astronomical Society journal, and
teaches
earth sciences at the University of Leeds
Copyright 1999, New Scientist
=============================
(3) PLUTO MAY BE 'DEMOTED'
From The BBC News Online
http://news.bbc.co.uk:80/hi/english/sci/tech/newsid_257000/257360.stm
by BBC News Online's Science Editor Dr David Whitehouse
In just a few weeks time tiny Pluto will regain its crown as the
most
distant planet orbiting the Sun. Soon afterwards however it may
lose
its planetary status forever.
Pluto revolves around the Sun every 248 years in a highly
elliptical
path. This means that for a few years every orbit it comes closer
to
the Sun than Neptune, the next most distant planet.
That will end at 11.22 GMT on February 11th when it will cross
Neptune's path and once again become the solar system's most
distant
planet.
It will be 220 years before it again comes closer than Neptune.
But
long before that it may have been demoted from its status as a
planet.
Depending upon an email vote among astronomers our solar system
may
soon have eight instead of nine planets as all the textbooks say.
Always strange
Discovered in 1930 Pluto almost defies classification, there is
no
other body quite like it. It is only two-thirds the diameter of
our
Moon and it has a relatively large companion Charon, discovered
in
1978.
Charon may have been born through a head-on collision between
Pluto and
another large ice body, in much the same way as the Earth-Moon
system
is believed to have formed.
According to computer models, some of the debris from this giant
impact
on Pluto went into orbit around Pluto and coalesced to form
Charon.
Made of a mixture of rock and ice Pluto has always been an
oddity. It
neither qualifies as an Earth-like or a gas giant planet.
Very little is known about its surface. Images taken by the
powerful
Hubble Space Telescope show only fuzzy details.
Experts disagree about what it is, but a growing number
say that if it was discovered now, it would never even
occur to them to call it a proper planet.
It may be the last survivor of a lost population of ice dwarfs
that
inhabited the primeval solar system. It may even be an escaped
satellite of Neptune.
Last to be visited
Pluto's significance in the solar system has been a point of
contention
since soon after it was discovered in 1930 by Clyde Tombaugh, an
astronomer at the Lowell Observatory in Arizona.
Since Tombaugh's death in 1997 pressure has grown for the
International
Astronomical Union, the international authority for naming
celestial
bodies, to take a tough line on Pluto.
The latest blow came in 1995 with the discovery of the first
object in
the so-called Kuiper Belt. Since then about 60 more objects, made
of
rock and ice and a few hundred km in size, have been found in the
solar
systems cold outer reaches.
Pluto remains the only major body in the solar system not to have
been
visited by a spacecraft. Plans are being drawn up for a mission
called
the Pluto-Kuiper Express that would fly past Pluto after having
spent
over ten years getting there.
One of the reasons scientists want to see it at close quarters is
that
despite its small size and remote location, Pluto undergoes
dramatic
seasonal changes.
As Pluto recedes from the Sun, much of its atmosphere is believed
to
freeze out onto the surface. This explains the observation of
fresh
white ice on its surface.
Copyright 1999, BBC
=================
(4) 20-YEAR EARTH TEMPERATURE RECORD
From NASA Science News
http://science.nasa.gov/newhome/headlines/essd12jan99_1.htm
Scientists Present 1998 Earth-Temperature Trends
Updated 20-year temperature record unveiled at 1999 AMS Meeting
January 12, 1999: Since late 1978, polar-orbiting satellites have
monitored the microwave emissions from oxygen in the Earth's
atmosphere. These emissions, measured with the Microwave Sounding
Unit (MSU) instruments aboard TIROS-N weather satellites, are
proportional to the temperature of the atmosphere, and have
allowed
scientists to build a 20-year record of the temperature of the
Earth
as measured from space.
==================
(5) A TUNGUSKA-TYPE EVENT IN 1867?
From Timo Niroma <timo.niroma@tilmari.pp.fi>
The Helsinki temperature shows a curious temporary decline in
1867 and
similarly that year was so cold all over in Finland that the
severe
frost caused a famine. A sizable percentage of the Finnish people
died
of hunger. Already the January had a mean temperature of -13.1
degrees
C, which was rivalled only in 1893, 1942, 1985 and 1987. By
comparison
the January 1866 had a mean temperature of -0.1 degrees. The
April
temperature was -1.1 degrees C, rivalled only in 1881. This means
the
second coldest April in 170 years (1829-1998).
May 1867 has then been the coldest in Helsinki during the last
170
years, mean temperature in Helsinki was only 1.8 degrees. This is
not
only the record, but several degrees below the second coldest
May. The
May 1866 had a temperature of 6 degrees, and the May 1868 a
temperature
of 8 degrees. The mean temperature in 1961-1990 was 10 degrees.
The
catastrophe was ready, June temperature being still below
average, 12.2
degrees. Only the July and August were nearly normal, 15 degrees
both,
but it was too late to get a normal harvest anymore and besides
at
nighttime there were severe frost.
In fact, something peculiar happened already in September 1866.
The
mean temperature was a high 14.3 degrees C, rivalled only in 1949
and
1955.
Although I here talk about Helsinki and Finland, there are
similar
measurements of a year without spring in 1867 in many other
places
around Europe and United States.
I have found three possible explanations.
1. Sun. As I show on my webpage
(personal.inet.fi/tiede/tilmari/sunspots.html) there exists a
clear
correlation between a low Sun (few sunspots) and a low
temperature on
Earth and a high Sun (rich sunspot activity) and a high
temperature.on
Earth. The most famous case is the Maunder minimum whose coldest
decade
in 1690's was both spotless in Sun and cold on Earth. Also during
the
1810's the Sun's activity was very low (in fact 1810 is the only
spotless year since 1749 since when we have monthly statistics).
The
maxima in 1805 and 1816 are also the lowest ones after 1749. So
Tambora
is not needed to explain the summerless year 1816 (although it
may have
helped a bit to lower it still). The chill years began already
years
before Tambora (for example the California cold in 1812-13).
In Helsinki temperature records (kept uninterruptibly since 1829)
the
warmest decade measured by summer temperatures is still the
1930's. In
1930's there began in Sun a growing trend in intensity. At the
moment
we are approaching surely the highest intensity for half a
millennium,
possible the highest since the medieval high in the 12th century.
This
correlates very well with the socalled "greenhouse
warming". As in the
Tambora case Sun is also here all that is needed for an
explanation of
the warming (see for example my web page, part 8). Correlation of
course doesn't mean a cause and effect relationship, but as
statistics
is based on probability, the more we have these correlations, the
more
confident we can be that such a relation exists. This of course
does
not exclude other factors (such as Tambora or man) supporting the
ongoing tendency.
But in 1867? There was a sunspot minimum in 1867, but it was a
typical
one, such that happens in intervals of 10-12 years, nothing like
in
1689-90 or in 1810, which most probable were the main reason for
the
cold decades of 1690's and 1810's, peaking 1695 and 1815-16,
respectively. In fact this cycle was the second highest in the
19th
century, so the Sun is not a likely explanation.
2. A volcano. The last frost event before 1867 in the United
States
occurred in 1837 and can be correlated with the volcanic eruption
of
Sopka in 1837 and the next occurred in 1884 and can be correlated
with
Krakatoa in 1883. But the frost event of 1867 in Europe and 1866
in US
cannot be correlated with any known volcanic activity.
3. An impact. "In 1867 the largest recorded flood disaster
occurred on
the Nepean River, Australia. When Saynor and Erskine (Australian
Journal of Marine and Freshwater Research 44(5), 1993) studied
sediment
cores along the river, they were able to identify high-level
flood
deposits dating to the 19th century inundation." A tsunami
or flood is
of course not a cause-and-effect indicator of an impact,
earthquakes
are more common reasons for tsunamis for example.
Now the big question is: was the anomalous frost event in 1866-67
caused by the same event that caused the flood disaster in 1867.
And
furthermore, could this event have been an impact near the
Australian
coastline, possibly of a size of 1 to 2 tunguskas?
Crowley-North: Paleoclimatology (Oxford 1991) indicates that this
was
not a Finnish-Australian event. Paris Summer temperature was
lowest
ever since the measurements began in late 18th century. The
acidity of
the Greenland ice sheet dropped to its lowest value since 540 AD.
There was a frost ring in bristlecone pine in western US in 1866
as
previously mentioned. There had been 29 years from the previous
frost
ring and would last 18 years to the next. The previous and the
next are
neatly correlated with big eruptions of volcanous, but the 1866
frost
event not. There is also another intriguing question: why was the
frost
event a year ahead in US than in Finland. If we assume an impact,
it
must have happened in 1866. If it occurred near Australia, could
it
have been possible that a blanketing dust veil prevailed over
western
US in 1866 and drifted to Greenland and Finland only in 1867?
A further interesting thing is that the Greenland
CO2concentration
dropped in 1868 from 240 ppm suddenly 180 ppm. There has been
other
drops also at other times, but the other drops has lasted a year
or
two, this lasted over a decade.
What then explains the a possible impact in 1866 and an
Australian
flood in 1867. Tsunami isn't that slow. If one looks at the
Nepean
area, the explanation is readily at hand. "Freshwater
wetland
communities were once common in backswamps along the Nepean,
Hawkesbury
and Georges Rivers and their tributary creeks. Most have now been
cleared or drained. Where they remain, permanent standing water
with no
emergent vegetation occupies the lowest areas of large swamps.
Around
this is more shallow water, with a zone of emergent
vegetation." (D. H.
Benson: The Native Vegetation Of Western Sydney.) If this kind of
land
gets a tsunami on it in 1866, it will still flood in 1867.
Timo Niroma
http://www.tilmari.pp.fi
================
(6) THE SOLAR GAS RECORD IN LUNAR SAMPLES AND METEORITES
R. Wieler: The solar noble gas record in lunar samples and
meteorites.
SPACE SCIENCE REVIEWS, 1998, Vol.85, No.1-2, pp.303-314
ETH ZURICH, ISOTOPE GEOL, NO C61, CH-8092 ZURICH, SWITZERLAND
Lunar soil and certain meteorites contain noble gases trapped
from the
solar wind at various times in the past. The progress in the last
decade to decipher these precious archives of solar history is
reviewed. The samples appear to contain two solar noble gas
components
with different isotopic composition. The solar wind component
resides
very close to grain surfaces and its isotopic composition is
identical
to that of present-day solar wind. Experimental evidence seems by
now
overwhelming that somewhat deeper inside the grains there exists
a
second, isotopically heavier component. To explain the origin of
this
component remains a challenge, because it is much too abundant to
be
readily reconciled with the known present day flux of solar
particles
with energies above those of the solar wind. The isotopic
composition
of solar wind noble gases may have changed slightly over the past
few
Ga, but such a change is not firmly established. The upper limit
of
similar to 5% per Ga for a secular increase of the He-3/He-4
ratio sets
stringent limits on the amount of He that may have been brought
from
the solar interior to the surface (cf. Bochsler, 1992). Relative
abundances of He, Ne, and Ar in present-day solar wind are the
same as the long term average recorded in metallic Fe grains in
meteorites within error limits of some 15-20%. Xe, and to a
lesser
extent Kr, are enriched in the solar wind similar to elements
with a
first ionisation potential < 10 eV, although Kr and Xe have
higher
FIPs. This can be explained if the ionisation time governs the
FIP
effect (Geiss and Bochsler, 1986). Copyright 1999,
Institute for
Scientific Information Inc.
==========================
(7) IS THE SUN A SUN-LIKE STAR?
B. Gustafsson: Is the Sun a Sun-like star? SPACE SCIENCE REVIEWS,
1998,
Vol.85, No.1-2, pp.419-428
ASTRONOMICAL OBSERVATORY, BOX 515, S-75120 UPPSALA, SWEDEN
Various observable properties of the Sun are compared with those
of
solar-type stars. It is concluded that the Sun, to a remarkable
degree,
is ''solar-type''. As regards its particular mass and age, and
probably
its non-binarity, ''anthropic'' explanations may seem in place.
The
possible tendency for the Sun, as compared with similar stars, to
be
somewhat rich in iron relative to other elements needs further
exploration. This is also true concerning its presently small
micro-variability amplitude. Copyright 1999, Institute for
Scientific
Information Inc.
========================
(8) SPECIAL ISSUE: THE CASSINI/HUYGENS MISSION
The Cassini Mission was launched in October 1997 to study
the physical
structure and chemical composition of Saturn as well as all its
moons.
PLANETARY AND SPACE SCIENCE, Vol.46 Iss.9-10 SEP-OCT 1998
SPECIAL ISSUE: THE CASSINI/HUYGENS MISSION
(1) Editorial
(2) A. Braccesi: Gian Domenico Cassini in Bologna and his
contributions to the assessment of the planetary system.
PLANETARY
AND SPACE SCIENCE, 1998, Vol.46, No.9-10, pp.1079- 1084
UNIVERSITY OF BOLOGNA, DIPARTIMENTO ASTRON, VIA ZAMBONI 33,
I-40126
BOLOGNA,ITALY
G. D. Cassini was hired as a professor of astronomy in Bologna in
1649, at the age of only 24, and left for Paris in 1669, when he
was
44. We will outline in this Paper his major contributions to
astronomy during those year according to the judgement of the
scholars: the demonstration of the physical inequality of the
Sun's
motion using the meridian line he had built in the church of S.
Petronio and the discovery of Mars and Jupiter rotation. The
first
result unequivocally dismissed Aristotle's celestial mechanics
based
on uniform circular motions, pointing to the unity of the
terrestrial and celestial worlds; the second contributed to renew
the
debate on whether the dynamical structure of the planetary system
was
Ptolemaic or Copernican. In this respect, some recently
discovered
lessons, which Cassini gave in Bologna in the year 1666, appear
enlightening. Excerpts are reported and commented upon. (C) 1998
Elsevier Science Ltd. All rights reserved.
(3) Titan in the solar system
(4) Some speculations on Titan's past, present and future
(5) The composition of Titan's atmosphere: a meteorological
perspective
(6) The dynamic meteorology of Titan
(7) Titan's ionosphere: A review
(8) Model of Titan's ionosphere with detailed hydrocarbon ion
chemistry
(9) A three-dimensional MHD model of plasma flow around Titan
(10)A two-dimensional multifluid MHD model of Titan's plasma
environment
(11)Dynamic escape of H from Titan as consequence of sputtering
induced heating
(12)The temperature dependent absorption cross sections of C4H2
at
mid ultraviolet wavelengths
(13)Cassini UVIS observations of Saturn's rings
(14)PPI results from the balloon drop experiment of the HASI
pressure
profile instrument
(15)The microwave sensing in the Cassini Mission: the radar from
Jet
Propulsion Laboratory (JPL
(16)Atmospheric calibration for precision Doppler tracking of
spacecraft
(17)Imaging spectroscopy of Saturn and its satellites: VIMS-V
onboard Cassini
(18)An imaging spectrometer operating in the visible near
infrared for the study of planetary surfaces
(19)VIRTIS: an imaging spectrometer for the ROSETTA mission
(20)Atmospheric studies with spectro-imaging: prospects for the
VIMS experiment on Cassini
(21)Investigation of Saturn's atmosphere by Cassini
(22)Analysis of dynamic performances of HASI temperature sensor
during the entry in the Titan atmosphere
(23)Cassini Huygens mission: the exploration of the Saturn
system.
Radio science experiments: Radio Frequency
Instrument
Subsystem
(24)Evolution of icy surfaces: an experimental approach
(25)Imaging Saturn's dust rings using energetic neutral atoms
(26)Cassini radar: system concept and simulation results
(27)Cassini as a heliospheric probe - the potential of pick-up
ion measurements during its cruise phase
(28)Scientific objectives and implementation of the Pressure
Profile Instrument (PPI/HASI) for the Huygens
spacecraft
(29)An Italian tracking station for Cassini
(30)Dynamically depleted zones for Cassini's safe passage beyond
Saturn's rings
(31)The Cassini-Huygens SSP refractometer: REF
(32)Doppler receiver for Cassini radio science experiments
(33)Fluid dynamics of liquids on Titan's surface
----------------------------------------
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*
LETTERS TO THE MODERATOR, 19 January 1999
-----------------------------------------
(1) CHANGING SWORDS INTO SPACESHIPS
Ian Crawford <iac@star.ucl.ac.uk>
(2) CHANGING WAR CRIMINALS INTO PACIFISTS?
Walt Hadley <walth@inter-linc.net>
(3) DEFENCE OF THE REALM & SPACE COLONISATION
Andrew Y. Glikson <aygsearch@cos.com.au>
================================
(1) CHANGING SWORDS INTO SPACESHIPS
From Ian Crawford <iac@star.ucl.ac.uk>
I am grateful to all those who have contributed to the debate
following my "swords into spaceships" contribution.
However, it seems
to me that several contributors have missed the essential points
of
my argument, which I would like to take this opportunity to
clarify.
The first point is that my original note was in response to
Andrew
Glikson's argument that expenditure on space development is
difficult
to justify ethically because the resources are required to
improve
conditions here on Earth. I certainly agree that there are many
global developmental and environmental projects which are more
deserving of support than space exploration. HOWEVER, as the
world
spends about $1 trillion p.a. on military hardware, and only
about
$0.02 trillion p.a. on civilian space projects, it is nonsensical
to
criticise the latter on ethical grounds without trying to do
something about the former (especially since the military
spending is
positively dangerous, whereas the much cheaper space programmes
are
at least harmless and, arguably, positively beneficial for
economic,
social and scientific reasons).
Having made this comparison, the next point is whether we should
go a
stage further and actually advocate financing space development
by a
transfer of resources from the (very large, but utterly
unproductive)
military sector of the world economy. I have presented these
arguments in the articles already referenced (New Scientist 19
May
1990, p. 67; Space Policy vol. 11, p. 219, 1995) and won't
reiterate
them all here. However, I would say that I am slightly
disappointed
by Pete Worden's "been there, done that" approach. Of
course it is
disappointing that nothing came of the SEI, however that isn't an
argument for giving up. The basic argument remains valid: the
Cold
War has ended, the military still soaks up at least 50 times the
resources currently devoted to space projects, the military
contractors are, very largely, the same ones that would be called
upon to develop a space infrastructure, and a transfer of
resources
from one to the other would therefore be largely compatible with
the
powerful corporate and political interests involved. What we need
to
do is to keep making the case.
I have to say that I disagree profoundly with Jim Benson's
arguments.
It cannot be true to say that we cannot "afford taxpayer's
dollars to
.... subsidize humans in space." If the US can afford $300
billion
p.a. on maintaining a vast military infrastructure (this being
approximately the US share of the $1 trillion p.a. global arms
budget
referred to above) then it can certainly *afford* a (say) $100
billion p.a. space programme (roughly ten times NASA's current
budget) PROVIDED that resources are transferred from one to the
other
(there being no other sector of the economy from which such a
transfer would be socially or politically justifiable). Of
course,
the extent to which this will ever be politically possible will
depend on perceptions of the geopolitical environment, and on
resulting political imperatives. However, as citizens who
presumably
want to live in a peaceful (and disarming) world, and who believe
in
the importance of space exploration/colonisation for the future
of
humanity, I believe that we should keep trying to draw these
arguments to the attention of policy makers.
Finally, I would like to express my agreement with Louis
Friedman,
and therefore disagreement with Benson, about the role of
government
in space. Of course private enerprise will have a role in
developing
the space frontier, but before this is likely to be significant
it
will be necessary to build up some sort of space infrastructure
(e.g.
economic ground-to-orbit spaceplanes, space stations,
interplanetary
transports, lunar and planetary outposts). Private industry is
most
unlikely to take the risk of building up such an infrastructure
when
the economic returns are so distant and so uncertain.
Infrastructural
development is an appropriate economic role for government, and
space
infrastructure will be no exception.
Ian Crawford
=================
(2) BEFORE GIVING UP YOUR SWORDS, GET RID OF WAR CRIMINALS FIRST
From Walt Hadley <walth@inter-linc.net>
Hi,
The concepts of peace and tranquility and little or no military
budgets
is a wonderful concept. It is also remarkably stupid! As a
retired
military officer, (line officer) I would very much like to live
in a
world like this. What I would like to know is how do some people
propose to rid the human race of the people that start wars, make
biological and nuclear weapons, make war on their neighbors. In
my
life of 66 years, I have seen no peace nor any sign of a time
when we
would not need a strong military, even in periods as now when we
do
not have one.
Walter H. Hadley
Major USAFR
======================
DEFENCE OF THE REALM & SPACE COLONISATION
From ANDREW Y. Glikson <aygsearch@cos.com.au>
Dear Benny,
I like to respond to comments by Julian Hiscox (CCNet 8.1.99) (my
reply points 1-4) and Ian Crawford (CCNet 13.1.99) (my reply
point 5)
"Defence of the realm and space colonisation" (CCNet
8.1.99), in the
context of biological evolution and human survival:
1. Survival of the oldest life forms: The present-day Shark Bay
stromatolite species (Cryptozoon) is of course different from the
3.5
billion years-old Pilbara species - the point in my letter
relates to
the longevity of single-celled colonial organisms, exceeding that
of
other species and that of Homo Sapiens by a factor larger than
700 000 000. I am unaware of confirmation of early Archaean
stromatolites from Greenland, where the main evidence for life
comes
from isotopically light carbon inclusions in apatite.
2. Biological success of parasitic versus symbiotic organisms:
The
survival of infectious micro-organisms, such as the smallpox
virus,
measles virus, pneumonia mycoplasms or tetanus germs, depends
critically on the availability of human carriers, on the longer
term
survival of the carriers - which these micro-organisms often kill
-
and on critical carrier population densities. Unless these
conditions are met, such micro-organisms recede to remote
niches. By
definition these species are self-limiting, as compared to
symbiotic
species. For Homo Sapiens the corollary is evident - good
planets
are hard to come by.
3. Exponential growth and the purpose of life:
If the sole
biological purpose of life is the promotion of the "Selfish
Gene"
(Richard Dawkins) through exponential growth aimed at maximising
mutational diversity, does human intelligence lie in (1) blind
adherence to "survival of the fittest" theories (whose
consequences
this century are evident) or (2) in an intelligent and ethical
choice
in favour of the qualitative value of life and of bio diversity?
This of course raises the question of determinism versus free
choice...
4. Prehistoric humans and modern civilisation:
The point to bear
in mind is that pre-historic humans have lived on Earth for some
5
million years in (relative) equilibrium with their environments,
developing an daptability that allowed them to survive calamities
such as asteroid/comet impacts.
Projectile size/frequency plots suggest that over 5000 impacts by
bodies larger than 100 meters occurred during the last 5 million
years (see fig. 13-1 in Verchuur's "Impact", Oxford
University Press,
1996). Regarding the "barbarism" or otherwise of
Amazonian tribes -
as J. Hiscox may be aware, some of the worst fatalities suffered
by
these people were due to infected blankets deliberately dropped
from
planes over their villages for many years ...
5. Arms into spaceships: I am in support space exploration for
scientific purposes, and could not agree more with Ian Crawford
that
conversion of arms into spaceships is much preferable to, as well
as
less destructive than, military expenditures. The point is
- by any
economic estimate the costs of space colonisation (establishment
of
human colonies on planets and moons) would exceed that of space
exploration (remote control surveys) by orders of magnitude.
Following western democratic principles, surly whether the
remaining
$$$trillions extracted from Earth's fast dwindling resources
should
be used for environmental restoration, alleviation of hunger,
or/and
space colonisation, is an issue which should be a subject for an
informed public debate, including inputs by life scientists
(biologists, botanists, foresters, soil scientists,
meteorologists)
with their understanding of the survival requirements of
terrestrial
living systems. The $$$hundreds of billions now expended on
attempts
to avert the Y2K bug underpin the futility of purely
tehcnological
solutions to the human condition. Had such sums been used
to plant
enough trees - the progressive encroachment of the terrestrial
deserts could perhaps be arrested, as well as jobs provided to
young
unemployed generations in many parts of the world ...
Choices relating to space exploration and colonisation go far
beyond
purely technical questions - but constitute major economic,
social
and ethical issues.
Andrew Glikson
16 January, 1999
aygsearch@cos.com.au
*
NOT TRUE THAT PLUTO IS DOWNGRADED
From Mark R. Kidger <mrk@ll.iac.es>
Benny:
I wrote a small piece on Pluto before the British media broke the
Pluto
story. Here is my text, based on an article which will appear in
"The
Astronomer" this month and which was put on my Web site here
in
Tenerife at Christmas.
Mark Kidger
---------------------
PLUTO: A NEW CLASS OF DUAL CITIZENSHIP
Mark R. Kidger
Instituto de Astrofisica de Canarias
According to a report published in the Boston Globe just before
Christmas, the Nomenclature Committee of the IAU (actually the
Executive Committee of Division III) has been holding an Internet
vote
over Christmas to decide on the fate of the planet Pluto. Within
a very
few weeks now, according to the Boston Globe article, Pluto may
cease
to be officially a planet and the solar system may return to its
8-planet status.
This story was picked up by the Spanish media around Christmas
and has
reached the British media this week. However, it seems that the
Boston
Globe was a little quick off the mark to downgrade Pluto with its
news
story. Gareth Williams at the Minor Planet Center issued a rapid
denial
of the story by Christmas, which was published on the Internet.
In
fact, the idea is to give Pluto "dual citizenship" as a
planet and the
king of the Trans-Neptunian Objects. This would even permit a
similar
double status for Ceres in the future.
For some time now it has become obvious that the outer solar
system
needs to be tidied up.. The number of TNOs (Trans-Neptunian
Objects),
making up the inner edge of the Kuiper Belt, has increased
steadily, to
approach 100. After the initial lack of follow-up observations of
many
of these objects such that at least one of the first discovered
(1993
RP) is totally and unretrievably lost, reliable orbits are being
calculated for a reasonable number of objects, although about
half have
still only been observed at a single opposition (often along an
arc of
only a few days). There is still a significant risk that a
sizeable
fraction of TNOs, particularly the fainter ones, may be lost
still.
Others, fortunately, are now multiple-opposition objects and are
beginning to satisfy the criteria for numbering.
At the current rate of asteroid discovery, Number 10 000 could
have
fallen as early as the January batch of Minor Planet Circulars,
where
new numbers are allocated. In fact, in January, after two months
where
more than 150 asteroids had been numbered, had a smaller crop
and, at
present, we are "only" at asteroid 9913 - when, twenty
years ago, the
prediction was made that 6000 might be reached by the millennium!
With asteroid 10 000 there is an obvious breakpoint to number
TNOs. A
logical thing to do is to number the best-observed now with 10
000-series numbers, to distinguish them from "normal"
asteroids and
maybe add new TNOs at 15 000 and 20 000 (at the current rate, 20
000
may be reached around mid-2005).
For some time now it has become clear that Pluto is nothing more
than
the largest of the objects of the Kuiper Belt. In fact, there is
a
whole class of TNOs with similar orbits which are called -
Plutinos -
little Plutos - which, it seems, are similar to their big brother
in
all but their size. Many times in the past the status of Pluto
has been
questioned and now it is being questioned more insistently than
ever.
What would the reasons be for down-grading Pluto? Even for those
emotionally tied to it as a planet, they are fairly convincing.
It is
now known that the mass of Pluto is only about one fifth of the
mass of
the Moon and, as such, it is very hard to claim that Pluto really
is a
planet. However, this still means that its mass is about
1.5x1022kg -
ten or more times the mass of Ceres, the largest asteroid. In
fact, of
the known TNOs, Pluto is still about a factor of 100 more massive
than
any other, apart from its satellite Charon and Charon is, by far,
the
second largest known TNO.
Doing some very rough numbers, it is likely that Pluto and Charon
make
up more than 50% of the mass of all the TNOs found to date. This
makes
Pluto an object intermediate in size and mass between the
asteroids and
Kuiper Belt comets on the one hand, and even Mercury, the
smallest
planet, on the other. This still marks Pluto as a special type of
object, which deserves a special status, but probably not as a
genuine
major planet.
As I understand it, the plan is to make Pluto asteroid number 10
000,
but the Minor Planet Center has denied that there is any plan to
remove
its planetary status. The title of the Boston Globe story,
"Planetary
Demotion" is misleading because Pluto will be both asteroid
number
10 000 and the ninth planet simultaneously. Other TNOs will then
follow
as 10 001, 10 002, etc.
The reason for the dual status is that there is a strong case for
both
sides. Pluto can be considered a major planet because, like the
others,
it is a gravitationally collapsed body (i.e. its interior has
been
differentiated as a consequence of heating by the collapse of its
mass), quite apart from the historical reasons which are so
important
to many people. However, as the largest object in the Kuiper
Belt,
there is undoubtedly a very strong case for including it as a
minor
body like the other Trans Neptunian Objects, quite apart from the
fact
that its mass is far smaller than for any other major planet.
By giving to Pluto the number (10000), in addition to retaining
it as
the ninth planet, we are giving Pluto a unique and very special
status.
This potentially allows Ceres to be given some kind of similar
double
status at a future date, as the largest object of the Asteroid
Belt.
The alternative proposal is to start a fourth list of solar
system
bodies (after the planets, the comets, and the asteroids). The
group
that supports this idea would like to designate Pluto as K/1 (for
Kuiper Belt Object #1), or TN-1 (for Trans-Neptunian Object #1).
The
problem with this option is obvious. There is a whole group of
objects
which are neither normal asteroids, nor strictly Trans-Neptunian
- the
Centaurs. Some Centaurs have already been numbered, the first
being
(2060) Chiron (although some might argue that (944) Hidalgo
should also
be considered a Centaur), but more have been added. Some Centaurs
are
recognised as having their aphelion in the Kuiper Belt and are
probably
objects in transfer orbits, others, may be dead or inactive
comets. The
question obviously arises of how to treat the Centaurs on this
scheme
and even of how to define a Centaur.
The numbered sequence (1)-(9913), or (1) - (10 000), merely
indicates
high-quality orbits of small objects of stellar appearance
orbiting the
sun. As Pluto's observable disk is actually smaller than that of
several asteroids, it is undoubtedly "of stellar
appearance", unlike
Uranus and Neptune which do have easily resolvable disks.
Just to make the debate a little more interesting, some people
even
argue that Pluto has actually shown itself to be an active comet.
When
it reached perihelion, sublimation for its surface gave rise to
an
extensive temporary atmosphere (a coma), which is recondensing as
Pluto
moves away from the Sun. If you really wanted to be difficult you
could
suggest that Pluto should be renamed C/1930 B1 (Thombaugh), or
C/1930
B1 (Pluto) - it could not be a periodic comet unless the rule
stating
that only objects of less than 200 years orbital period should be
designated as a periodic comet. This was the solution adopted for
Chiron which is now designated both (2060) Chiron (as an
asteroid) and
as 95P/Chiron (as a periodic comet observed now at three
perihelion
passages since 1895 and at no less than 29 oppositions). If the
same
rule were followed for Pluto, it would become 141P/Pluto, always
supposing that the 200-year period rule could be waived. Such a
solution would certainly maintain Pluto's name and give it a
special
status. The objection here is that comets and planets are clearly
different type of object, whilst asteroids and planets are
generically
similar - to have an object classed as comet and planet would
take us
back to the days of Velikovsky.
However, designating Pluto as 141P/Pluto does not have the
element of
"ceremonial gesture”" which beholds its status as,
after all, it would
be just another comet. In contrast, asteroid 10 000 does lend
itself to
ceremony, particularly as the Minor Planet Center has
traditionally
arranged a celebration every 1000 asteroids and to reach number
10 000
is a major landmark which should be marked by something more
distinguished than a tiny, rock which is never brighter than
magnitude
20 (which most of the new numbered asteroids are). This makes
Pluto a
fitting candidate.
The most intriguing option though is that, assuming number 10 000
is
not reached in the January list of new minor planet designations,
it
would be reached in the February list which should be released on
or
about February 10th 1999. This, as was pointed out by the Dutch
scientific journalist, Govert Schilling, would coincide with the
day
when Pluto crosses Neptune's orbit towards aphelion and, once
again,
becomes the most distant planet. If you want a symbolic gesture,
what
finer one could there be than that!
Copyright 1999, Mark R. Kidger