PLEASE NOTE:
*
CCNet, 68/2000 - 13 June 2000
------------------------------
"The largest robotic telescope so
far is the 80-inch Liverpool
Robotic Telescope, which is now under
construction. It will be
located in La Palma in the Canary
Islands, and monitored from a
control center 2000 miles away in the
United Kingdom. 'It’s like
having a space probe on the ground'
Michael Bode of the Liverpool
John Moores University told Space.Com.
If an astronomer needs the
telescope to look at something special
that night, it can be
re-programmed via the Internet to halt
its planned observing
schedule and go looking off in another
direction. Bode’s goal is
to ultimately build "RoboNet"
six duplicate telescopes equally
spaced around the globe. Tied together
by the Internet, they would
provide non-stop coverage of any
unfolding celestial drama."
-- Ray
Villard, Space.com, 11 June 2000
"Everything about the origin of
life on earth is a mystery, and it
seems the more that is known, the more
acute the puzzles get."
--
Nicolas Wade, The New York Times, 13 June 2000
(1) ROBOTIC TELESCOPES: THE FUTURE OF WHOLE SKY SURVEILLANCE
Space.com, 11 June 2000
(2) LIFE'S ORIGINS GET MURKIER AND MESSIER
The New York Times, 13 June 2000
(3) FIREBALL OBSERVED OVER COLORADO
Ron Baalke <baalke@jpl.nasa.gov>
(4) FUGITIVES FRTOM THE EROS FAMILY
V. Zappala et al., OSSERV ASTRON TORINO
(5) SIZE & SHAPE OF TROJAN ASTEROID (1437) DIOMEDES
I. Sato et al., WATANABE TECHNOL LAB
(6) EARTH TROJAN ASTEROIDS
P. Wiegert et al., YORK UNIVERSITY
(7) RADAR MICROMETEOR OBSERVATIONS
D. Janches et al., PENN STATE UNIVERSITY
(8) WAVE DISTURBANCES FROM THE COMET SL-P IMPACTS ON JUPITER
R.L. Walterscheid et al., AEROSP CORP
(9) EFFECTS OF COMETESIMAL COLLISIONS
S. Sirono& J.M. Greenberg, HOKKAIDO
UNIVERSITY
(10) GREAT BALL OF FIRE IN AUGUST 1571?
Luz Santamarta <l_lmsl@hotmail.com>
(11) DEMILILITARIZED PLUTONIUM COULD BE USED FOR
PLANETARY DEFENSE & SPACE
EXPLORATION
Mark Sonter <sonter@camtech.net.au>
(12) INSTANT ASTEROID DEATH A BLESSING COMPARED TO CONTINUING
USE OF NUCLEAR POWER
Russell D. Hoffman <rhoffman@animatedsoftware.com>
==========
(1) ROBOTIC TELESCOPES: THE FUTURE OF WHOLE SKY SURVEILLANCE
From Space.com, 11 June 2000
http://www.space.com/scienceastronomy/astronomy/robotic_telescopes_000608.html
Robotic Telescopes Keep Universe Under Surveillance
By Ray Villard
The nighttime sky looks deceptively tranquil. In reality it is
alive
with a variety of brief but violent outbursts popping on and off
like
July 4th fireworks. Stars explode in faraway galaxies and neutron
stars
hiccup in a burst of radiation as they devour companion stars.
Mysterious blasts of gamma rays, possibly from collapsing black
holes,
zap earth from deep space.
It’s a daunting task for astronomers to keep an eye on all
these
spectacular but totally unpredictable happenings. Yet, they are
critical to understanding the most violent activities affecting
our
universe.
Needle in the haystack
Catching sight of these so-called transient phenomena is like
looking
for a needle in a haystack. An astronomer typically spends only a
few
nights per year looking at a selection of predetermined celestial
targets. Aside from doing a tedious survey, coming across a
cosmic
"flash-in-the-pan" has been largely good luck -- being
at the right
place at the right time.
Enter the "robo-telecope" an autonomous, rapid response
all-sky
monitor, where silicon not only replaces the human eye, but
largely the
human brain. Like surveillance cameras in a department store,
robo-telescopes, sitting alone and untended on isolated mountain
tops,
nightly patrol the sky, looking for any changes from the far
corners of
the universe. They move quickly and precisely, relying on their
own
onboard sky maps to prowl the heavens. The nightly flood of data
is
automatically archived and analyzed to note any changes in the
present
state-of-the universe.
Robo-telescopes are a boon to astronomers who want to catalog
variable
stars. They are ideal for studying supernovae (exploding stars)
as well
as the optical counterparts to gamma-ray bursts, the most
powerful
explosions known in the universe. And a host of other elusive and
exotic phenomena are well suited to the robo-telescope concept.
Big bang of information for astronomers
The result has been a "big bang" of information for
astronomers.
Research that required over a decade of meticulous and patient
observation can be now accomplished in a few months by these
tireless,
efficient sky sentinels. The nightly sky harvest has yielded huge
databases of new phenomena that would have gone forever unnoticed
by
traditional human-tended observing techniques.
Located at Lick Observatory atop Mount Hamilton near San Jose,
CA, the
Katzman Automatic Imaging Telescope (KAIT) is an entirely
autonomous
telescope dedicated to searching for supernovae in 1,000 galaxies
nightly. It also monitors a variety of other elusive celestial
phenomena.
"This is a huge revolution in astronomy, where massive data
processing,
large format electronic imaging detectors (called charge-coupled
devices, or CCDs), and the Internet have all suddenly come
together to
fundamentally change the way we explore the universe," said
Jeffrey
Bloch of the Los Alamos National Laboratory.
At Lick Observatory on Mt. Hamilton outside San Jose, Calif., a
30-inch
mirror robotic telescope called the Katzman Automatic Imaging
Telescope
(KAIT) checks in on 1,000 galaxies every night. The telescope
hunts for
an elusive prey -- the flicker of light from a star that has
self-destructed as a supernova. For a brief instant in the star’s
life
it shines with the radiance of an entire galaxy.
Weather-check
Every night computers check the weather, automatically open the
observatory dome, point and focus the telescope and take digital
pictures. The images are sent via the Internet to a computer at
the
University of California at Berkeley, where they are compared
automatically to earlier pictures of the same region of sky.
Images
with new points of light are flagged so that the next morning
astronomers can double-check them and identify the best
candidates.
Since it began operation in 1996, KAIT has pinpointed 70
supernovas in
galaxies within 500 million light years of earth. "KAIT
finds
essentially all of the supernovas in the galaxies we
monitor. We are
surprised to find so many supernovas in such a short amount of
time,"
says Alex Filippenko of UC Berkeley.
Filippenko and colleagues are building a much better idea of how
common
supernovas are, and how they vary in behavior. The supernovas are
invaluable for studying the origin of elements, and the expansion
rate
of the universe.
Rapid-response sky hunter
Another rapid-respond sky hunter is the University of Michigan’s
Robotic Optical Transient Search Experiment (ROTSE), consisting
of four
telephoto photographic lenses mounted on CCDs. When a gamma-ray
burst
goes off, its position as measured by a constellation of
satellites is
automatically and instantly relayed to ROTSE. Within three
seconds of
the receipt of this information ROTSE pivots to the target
position,
and begins snapping off pictures to pinpoint the rapidly fading
optical
fireball resulting from the burst.
The largest robotic telescope so far is the 80-inch Liverpool
Robotic
Telescope, which is now under construction. It will be located in
La
Palma in the Canary Islands, and monitored from a control center
2000
miles away in the United Kingdom. "It’s like having a
space probe on
the ground" Michael Bode of the Liverpool John Moores
University told
Space.Com. If an astronomer needs the telescope to look at
something
special that night, it can be re-programmed via the Internet to
halt
its planned observing schedule and go looking off in another
direction.
Bode’s goal is to ultimately build "RoboNet" six
duplicate telescopes
equally spaced around the globe. Tied together by the Internet,
they
would provide non-stop coverage of any unfolding celestial drama.
Such
a "whole earth" telescope could look for planets beyond
the sun by
continuously monitoring the light from many stars simultaneously.
A
subtle and transitory brightening of a star’s light would
signal the
passage of an intervening planet.
Copyright 2000, Space.com
===================
(2) LIFE'S ORIGINS GET MURKIER AND MESSIER
From The New York Times, 13 June 2000
http://www.nytimes.com/library/national/science/061300sci-life-origins.html
Genetic Analysis Yields Intimations of a Primordial Commune
By NICHOLAS WADE
The surface of the earth is molten rock. The oceans are steam or
superheated water. Every so often a wandering asteroid slams in
with such energy that any incipient crust of hardened rock is
melted
again and the oceans are reboiled to an incandescent mist.
Welcome to Hades, or at least to what geologists call the Hadean
interval of earth's history. It is reckoned to have lasted from
the
planet's formation 4.6 billion years ago until 3.8 billion years
ago,
when the rain of ocean-boiling asteroids ended.
The Isua greenstone belt of western Greenland, one of the oldest
known
rocks, was formed as the Hadean interval ended. And amazingly, to
judge
by chemical traces in the Isuan rocks, life on earth was already
old.
Everything about the origin of life on earth is a mystery, and it
seems
the more that is known, the more acute the puzzles get.
The dates have become increasingly awkward. Instead of there
being
a billion or so years for the first cells to emerge from a warm
broth of chemicals, life seems to pop up almost instantly after
the last of the titanic asteroid impacts that routinely
sterilized
the infant planet.
FULL STORY at:
http://www.nytimes.com/library/national/science/061300sci-life-origins.html
==================
(3) FIREBALL OBSERVED OVER COLORADO
From Ron Baalke <baalke@jpl.nasa.gov>
Eyeball On the Fireball: Meteorite Lights Up Colorado Night
By Andrew Bridges
space.com
09 June 2000
Scientists from the Denver Museum of Nature and Science are
continuing
to interview eyewitnesses about a recent fireball that
illuminated the
Colorado night, dazzling holiday campers with an explosive
display of
nature's majesty.
The museum has recorded interviews with more than 200 people who
witnessed the bolide streak northward across the night sky before
exploding in a shower of sparks, perhaps showering meteorite
fragments
across a forested, mountainous swath of the western state.
"Anyone who was out camping that weekend was blown away by
the sight,"
said Laura Danly, the museum's space-science curator.
Full story here:
http://www.space.com/scienceastronomy/astronomy/fireball_colorado_000609.html
=======================
(4) FUGITIVES FROM THE EROS FAMILY
V. Zappala*), P. Bendjoya, A. Cellino, M. DiMartino, A.
Doressoundiram,
A. Manara, F. Migliorini: Fugitives from the Eos family: First
spectroscopic confirmation. ICARUS, 2000, Vol.145, No.1, pp.4-11
*) OSSERV ASTRON TORINO,I-10025 PINO TORINESE,ITALY
The fact that some asteroids presently located in the 9/4
mean-motion
resonance with Jupiter could be ''Eos fugitives,'' that is,
original
members of this asteroid family injected into the resonance and
experiencing a gradual eccentricity increase, was first suggested
a few
years ago (Morbidelli, A., V. Zappala, M, Moons, A. Cellino, and
R.
Gonczi 1995, Icarus 118, 132-154), We present here the results of
a
campaign of spectroscopic observations of candidate Eos
fugitives, and
we confirm that some of these objects should come from this
family,
according to their observed spectral characteristics. We find
also
indications that these objects are probably relatively young. We
can
conclude that Eos fugitives are a first example of family objects
observed during the dynamical process of leaving the asteroid
main
belt. The results confirm current ideas about the dynamics
governing
bodies injected into the 9/4 resonance. This can be important
also from
the point of view of a possible relationship between the Eos
family and
CV/CO chondrites as suggested by spectral analogies. (C) 2000
Academic
Press.
=============
(5) SIZE & SHAPE OF TROJAN ASTEROID (1437) DIOMEDES
I. Sato*), L. Sarounova, H. Fukushima: Size and shape of Trojan
asteroid diomedes from its occultation and photometry. ICARUS,
2000,
Vol.145, No.1, pp.25-32
*) WATANABE TECHNOL LAB,SUNRIZE AKIMOTO BLDG 401,2-8-17
KYONANCHO,MUSASHINO,TOKYO 1800023,JAPAN
The first Trojan asteroid occultation, the occultation of HIP
014402A
by (1437) Diomedes, was successfully observed from Japan on
November 7,
1997, From its occultation timings at six sites including two
video
observations, an elongated occultation silhouette of (180 +/- 28
km) x
(96 +/- 5 km), at position angle PA = 150 +/- 4 degrees was
revealed.
Follow-up photometry of Diomedes obtained at Ondrejov on November
10
and 11 and at Mitaka on November 18, 19, and 24 revealed that its
rotation period is 1.019 +/- 0.004 days, its amplitude of light
variation is 0.70 +/- 0.15 mag, and its rotational phase at the
occultation was almost at a minimum of the lightcurve. From these
observations, a probability distribution ellipsoidal model for
Diomedes
is derived, It shows that two families of ellipsoidal models are
possible. One is a triaxial ellipsoid of b/a approximate to 0.55;
the
other is a rather prolate ellipsoid of b/a approximate to 0.4,
c/b
approximate to 1. Possible orientation of the rotation axis is
very
restricted to two great circles on the celestial sphere. Mean
lengths
of the three principal axes of the model ellipsoid are (284 +/-
61 km)
x (126 +/- 35 km) x (65 +/- 24 km), i.e., approximately a : b : c
approximate to 4 :2: 1. (C) 2000 Academic Press.
======
(6) EARTH TROJAN ASTEROIDS
P. Wiegert*), K. Innanen, S. Mikkola: Earth Trojan asteroids: A
study
in support of observational searches. ICARUS, 2000, Vol.145,
No.1,
pp.33-43
*) YORK UNIVERSITY,DEPT PHYS & ASTRON,TORONTO,ON M3J
1P3,CANADA
Observational searches for asteroids orbiting near Earth's
triangular
Lagrange points face unique obstacles. A population of such
asteroids
would occupy a large projected area on the sky (possibly hundreds
of
square degrees) and is not favorably placed with respect to the
Sun.
Here we examine the properties of synthetic populations of Earth
''Trojans'' in order to aid in the optimization of observational
searches for them. We find that the highest on-sky projected
number
densities are not located at the positions of the L-4 and L-5
points
themselves, but rather a few degrees closer to the Sun. Also,
asteroids
on orbits about the L-4 and L-5 points typically brighten as the
difference between their ecliptic longitude and that of the Sun
increases owing to phase effects, but their number density on the
sky
concurrently falls rapidly. (C) 2000 Academic Press.
==========
(7) RADAR MICROMETEOR OBSERVATIONS
D. Janches*), J.D. Mathews, D.D. Meisel, Q.H. Zhou: Micrometeor
observations using the Arecibo 430 MHz radar I. Determination of
the
ballistic parameter from measured Doppler velocity and
deceleration
results. ICARUS, 2000, Vol.145, No.1, pp.53-63
*) PENN STATE UNIVERSITY,COMMUN & SPACE SCI LAB,316 EE
E,UNIVERSITY
PK,PA,16802
We present a sample of radar meteors detected during the November
1997
Leonids shower period using the narrow-beam, high-power Arecibo
Observatory 430-MHz radar. During this period similar to 7700
events
were detected over 73 h of observations that included six
mornings.
Near apex-crossing, 6-10 events per minute were observed in the
similar
to 300-m diameter beam. From these events a total of 390 meteors
are
characterized by a clear linear deceleration as derived from
the radial Doppler speed determined from the meteor-echo
leading-edge
(head-echo). We interpret our results in terms of the meteor
ballistic
parameter-the ratio of the meteoroid mass to cross-sectional
area-yielding a physical characterization of these particles
prior to
any assumptions regarding meteoroid shape and mass density. In
addition, we compare these measurements with the results of a
numerical
solution of the meteor deceleration equation and find them in
good
agreement. The size and dynamical mass of the meteoroids are
estimated
considering these particles to be spheres with densities of 3
g/cm(3).
We also discuss atmospheric energy-loss mechanisms of these
meteroids.
We believe these are the first radar meteor decelerations
detected
since those ones reported by J. V. Evans (1966, J. Geophys, Res.
71,
171-188) and F. Verniani (1966, J. Geophys, Res, 71, 2749-2761;
1973,
J. Geophys, Res, 78, 8429-8462) and the first ones for meteors of
this
size. (C) 2000 Academic Press.
=========
(8) WAVE DISTURBANCES FROM THE COMET SL-9 IMPACTS ON JUPITER
R.L. Walterscheid*), D.G. Brinkman, G. Schubert: Wave
disturbances from
the comet SL-9 impacts into Jupiter's atmosphere. ICARUS, 2000,
Vol.145, No.1, pp.140-146
*) AEROSP CORP,SPACE & ENVIRONM TECHNOL CTR,POB 92957,LOS
ANGELES,CA,90009
Wave disturbances due to the Shoemaker-Levy 9 (SL-9) cometary
impacts
into Jupiter's atmosphere have been simulated with a fully
compressible
(nonhydrostatic), time-dependent, nonlinear, axisymmetric,
f-plane,
finite difference computational scheme, Energy is released in a
cylindrical region with a radius of 250 to 1000 km as suggested
by
models of the reentry of impact ejecta following the initial
explosion.
The model produces outward moving gravity waves at stratospheric
altitudes with speeds and relative amplitudes in agreement with
observations. The waves emerge from a cylindrical region of
alternating
inflow and outflow that extends high into the atmosphere in the
main
region of energy release, The disturbances originate as
horizontally
propagating waves at the periphery of this region, thereby
providing an
explanation for the observed large initial radius (similar to
450-700
km) of the main ring. The model results suggest that the waves
are made
visible by the inflow of particulate impact debris into outward
moving
rings of wave horizontal convergence. The inner edge of the
extensive
clear zone outside of the main dark ring may be the divergence
phase of
the leading fast wave. The results of this study remove the
necessity
to invoke a stable, water-rich, wave-trapping layer in Jupiter's
atmosphere in order to understand the Comet SL-9 observations of
dark
wave-like rings expanding radially away from the impact sites.
(C) 2000
Academic Press.
============
(9) EFFECTS OF COMETESIMAL COLLISIONS
S. Sirono*), J.M. Greenberg: Do cometesimal collisions lead to
bound
rubble piles or to aggregates held together by gravity? ICARUS,
2000,
Vol.145, No.1, pp.230-238
*) HOKKAIDO UNIV,DEPT EARTH & PLANETARY SCI,SAPPORO,HOKKAIDO
060081,JAPAN
Although the collisions of cometesimals have been widely
discussed in
the context of the so-called ''rubble-pile'' model of comet
nuclei,
there has been little discussion of the physical consequences of
collisions between cometesimals, Here we calculate analytically
the
compressive strength of grain aggregates which compose the
cometesimals
and discuss possible consequences of collisions of cometesimals,
It is
shown that heterogeneity in density results from collisions
between
cometesimals in a protoplanetary nebula and that the forces
necessary
to separate the merged cometesimals are orders of magnitude
larger than
gravitational attraction. Similarly, substantial compaction takes
place
in the regions of the Kuiperbelt and the collisions result in
relatively tightly bound aggregates. (C) 2000 Academic Press.
=============================
* LETTERS TO THE MODERATOR *
=============================
(10) GREAT BALL OF FIRE IN AUGUST 1571?
From Luz Santamarta <l_lmsl@hotmail.com>
Dear Sir,
Let me introduce myself. I am a Spanish student who is doing
research work for Oviedo University in the field of English
History. In the develoment of my thesis, I have come across of
some information that states that at the beginning of August 1571
some people saw "a great circle of fire in the Heaven",
I guess a
comet. I have already made this enquiry to your colleague Mr.
Robin Catchpole, who kindly has recommendmed me to get in contact
with you due that he has not found the information requested.
Therefore, I would like to ask you if there was any comet or
another phenomenon visible from the British Isles during those
days I have already mentioned.
Looking forward to hearing from you soon,
yours faithfully,
Luz Marķa Santamarta Lozano
Universidad de Oviedo
Spain
======================
(11) DEMILILITARIZED PLUTONIUM COULD BE USED FOR
PLANETARY DEFENSE & SPACE
EXPLORATION
From Mark Sonter <sonter@camtech.net.au>
Dear Benny,
With reference to Bob Kobres' posting regarding the Clinton -
Putin
deal to demilitarize umpteen tonnes of plutonium:
This stuff should be used in nuclear rockets, for Impact Threat
defence, and for opening up the solar system to human visitation.
The NERVA design of the 1960's pumped hydrogen through a sealed
high
temperature reactorcore, to achieve some tens of thousands of
kilograms
(sorry, hundreds of thousands of Newtons) thrust, at Specific
Impulse
of something like 800 seconds. This stuff actually ran, in
several
ground based test-firings.
The Orion design proposed exploding bomblets behind a pusher
plate:
read all about it in Freeman Dyson's "Disturbing the
Universe". Their
motto was "Saturn by 1970", and they meant manned
missions!!!.
Some years ago, the ever-fertile mind of Bob Zubrin proposed a
"Nuclear
Salt-Water Rocket", fuelled by a few percent solution of
U235-nitrate
or similar, with the solution (stored in a fuel tank intersected
with
boron or cadmium plates to ensure subcritcality) pumped into a
reaction
chamber where it is allowed to go critical and flash to 10 000 K
plasma, giving a Specific impulse of (maybe) 10 000 seconds and a
thrust of tens of thousands of Newtons.
Now, Carlos Rubbia of CERN has proposed another, vaguely similar
concept, again using fission products as the exhaust mass to give
an
enormous Specific Impulse.
Point to note: if we want to be able to get to Mars in a few days
rather than six months, which is Rubbia's desire, OR if we want
to be
able to get out to a threatening impactor on a cometary orbit,
and
intercept it at a decent distance from Mother Earth, (the further
away,
the lower the impulse requirement for successful deflection) then
the
most energy density is available in nuclear fuel.
The requirement for high thrust AND high Isp (specific
impulse)
--which is what determines the delta-v capability of your
rocket-- --
is only achievable via an exotic, very energetic, nuclear
propulsion
method.
Mark Sonter
===============
(12) INSTANT ASTEROID DEATH A BLESSING COMPARED TO CONTINUING
USE OF NUCLEAR POWER
From Russell D. Hoffman <rhoffman@animatedsoftware.com>
Re: CCNet, 64/2000 - 5 June 2000
"Armageddon - triggered by an
asteroid hurtling into our planet -
is a genuine risk. Now some
scientists are pressing the European
Space Agency (Esa) to construct a
satellite called Gaia which
could pinpoint errant chunks of
rock that threaten Earth. The
probe - the most accurate
telescope ever built - would track
objects a kilometre or more in
diameter, allowing scientists to
predict their path years before
their collision with our planet.
Rocket-born nuclear bombs could
then be launched to nudge them
from their deadly paths."
-- Robin McKie, The Observer
Dear Dr. Peiser:
Your opening quote (shown below) for Monday, June 5th, 2000's
CCNet was
astounding. To realize to what extent the nuclear dream lives on
would
be funny if it wasn't so dangerous.
While Robin McKie is dreaming of nudging big rocks with nuclear
bombs
(while somehow managing not to disintegrate them into irradiated
chunks, thus creating a whole-Earth firestorm and subsequent
burnt-ember winter as the world's forests all incinerate at once,
real-life experience with nuclear materials for more than 50
years
indicates, over and over, that the mere process of mining,
transporting, purifying, transporting, molding and milling, and
finally
transporting whatever to wherever is, in itself, a burden --
indeed, a
pox -- upon society. Who bears the burden of failures whilst
waiting
for THE BIG ASTEROID, ever-and-again preparing nuclear solutions
to
serious -- but solvable by many alternate methods -- problems?
The
answer is we do. Our bodies do, in the form of cancer, leukemia,
and
birth defects.
Energy? Nuclear Power Plants. War? Nuclear Intercontinental
Ballistic
Missiles. Incoming ICBMs? Nuclear-powered lasers. Asteroids?
Nuclear
Bombs. Cancer caused by all these other "solutions"?
Why, you've got a
nuclear solution for that too: Chemotherapy and other radiation
treatments, which are
closing-the-door-after-the-horse-has-left-the-barn
sorts of solutions in the first place (cancer prevention is a far
better practice) and which are often totally ineffective, and add
a
radiological burden to the rest of society as the waste products
and
byproducts of these treatments enter the human eco-stream.
For this particular case, your solution to an approaching
doomsday
asteroid, one that's just a certain size -- bigger, and there
would be
nothing we could do about it, smaller, and we could use other
methods
to solve the problem -- but for that perfect asteroid for which
you
want to support the entire Nuclear Mafia and the Demon Hot Atom,
try
this: Get to it sooner, nudge it more gently but over a longer
period
of time, and expect it to miss us by mere inches. Move the
entire
human and animal population away from the impact zone.
Indeed, I have fought all my life for just the tools to allow us
to do
those very things. For example, for decades I have advocated a
permanently-staffed moon base, from where the heavens could be
closely
studied, so we could anticipate these things sooner. It could
also
serve as a "starter colony" for human life should Earth
become
uninhabitable for a few years or even centuries (however, if it
becomes
a nuclear wasteland, it will have to be abandoned for a good deal
longer than that). And I have advocated for greatly increased use
of
public transportation systems, which could be used to move large
populations away from impact zones quickly and efficiently.
The question, then, is what is the most efficient way to reduce
the
dangers from asteroids?
Perhaps it is best that we nudge asteroids lightly, not breaking
them
up for others to have to deal with the pieces, at least some of
which
will spread out at terrific speeds from the original trajectory
and
from the other pieces after even a "small" nuclear
blast. Instead we
need to nudge them for longer periods, in non-nuclear ways. We
can
choose to nudge things either way, either or both systems could
be
implemented, and humanity has many choices. It's worth trying the
non-nuclear solution, because the nuclear solutions we
continually
embrace are choking this planet to death -- it can be fairly
argued
that a nearly instant asteroid death would be a blessing in
comparison
to what is being done here spill by spill, dilution by dilution,
leakage by leakage, drop by drop. There is No Minimum Dose, and
humanity suffers daily from the effects of choosing the nuclear
"solution" to each problem we face.
Sincerely,
Russell Hoffman
Carlsbad, California
----------------------------------------
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