PLEASE NOTE:
*
CCNet 23/2001 - 8 February 2001
-------------------------------
"For a long time now, Earthlings have been threatening to
move
heaven and Earth in order to get this or that accomplished.
Politicians
promise to do so before every election. Moms seem to manage, at
least
metaphorically, to do it every day. Now a group of scientists
says it
could be done for real."
--Robert Roy Britt, Space.com, 7 February 2001
"There is, of course, no need to move our planets position
in the
solar system. [...]
Perhaps the most interesting implication of this suggestion is
what
it means for the human race as a whole. The Russian astronomer
Nikolai
Kardashev suggested that civilisations could be classified into
four groups
of which ours is a type 0 civilisation, struggling for survival
on a single
planet that we can't control. The knowledge and the ability to
modify the
configuration of a planetary system to create a more hospitable
and
efficient environment is one of the criteria for a type II
civilisation. Shifting planets around in a game of cosmic
billiards
being an ingenious alternative to the construction of a Dyson
sphere. We
now have the knowledge and the ability, all we lack is the
impetus. In short
it appears the human race has just been promoted."
--Matthew Genge, The Natural History Museum, 7 February 2001
(1) UA SCIENCE TEAM READIES FOR NEAR LANDING
Ron Baalke <baalke@jpl.nasa.gov>
(2) RECIPE FOR SAVING EARTH: MOVE IT
Space.com, 7 February 2001
(3) DEBRIS COLLISION ADVOIDANCE PREDICTIONS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(4) SPECTAL FEATURES USED TO DETERMINE ORBITAL DEBRIS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(5) REMINDER: RAS MEETING TOMORROW ON THE GEOLOGICAL RECORD OF
IMPACTS ON
THE EARTH
Jacqueline Mitton <aco01@dial.pipex.com>
(6) PERMO-TRIASSIC
Doug Erwin <Erwin.Doug@NMNH.SI.EDU>
(7) COSMIC BILLIARDS AND THE PROMOTION OF THE HUMAN RACE
Matthew Genge <M.Genge@nhm.ac.uk>
(8) A BETTER UNDERSTANDING OF DR. SIMONENKO'S POSITION
Worth Crouch <doagain@jps.net>
(9) PLANETARY DEFENSE
Andy Smith <astrosafe@yahoo.com>
============
(1) UA SCIENCE TEAM READIES FOR NEAR LANDING
From Ron Baalke <baalke@jpl.nasa.gov>
http://uanews.opi.arizona.edu/cgi-bin/WebObjects/UANews.woa/wa/SRStoryDetails?ArticleID=3134
UA SCIENCE TEAM READIES FOR NEAR LANDING
(From Agnieszka Przychodzen, UA Lunar and Planetary Lab)
CONTACT: William V. Boynton, 520-621-6941, wboynton@lpl.arizona.edu
(EDITORS - Boynton is available for interviews at the UA through
Friday,
Feb. 9)
NASA's Near Earth Asteroid Rendezvous (NEAR) mission, the first
to orbit an
asteroid, is coming to an end.
February 7, 2001
With the spacecraft almost out of fuel, on Feb. 12 mission
engineers will
attempt the first-ever, controlled descent to the surface of an
asteroid.
NEAR has been orbiting asteroid 433 Eros since Feb. 14, 2000 and
is now more
than 196 million miles (316 million kilometers) from Earth
The main goal of the controlled descent is to gather close-up
pictures of
the surface of Eros, particularly the saddle area, a six-mile
(10-km) wide
depression peppered with huge boulders and cut with grooves.
"The landing will take a few hours. We'll see the images
coming in real time
as the NEAR spacecraft is approaching closer and closer to the
asteroid's
surface," William V. Boynton said. Boynton, professor
of planetary sciences
in the UA Lunar and Planetary Laboratory, leads the UA group
involved in the
NEAR mission.
Boyton and the UA team will watch the descent at the Applied
Physics
Laboratory (APL) in Laurel, Md., which built the spacecraft and
managed the
mission.
NEAR Shoemaker's 4-hour descent is scheduled to start at 10:31
a.m. EST. A
series of thruster firings will decelerate the spacecraft from
about 20 mph
to 5 mph.
"It is not really a landing in the sense of a spacecraft
being alive once it
touches down. NEAR has no legs to steady it, so it's just going
to fall
over. The antenna will no longer point to the Earth so we'll not
be able to
communicate with it," Boynton said.
NEAR's camera will be taking a photo every minute. The last clear
images,
shot from about 1,650 feet (500 meters), could details on the
surface as
small as 4 inches (10 centimeters) across.
"If the instruments survive the touch down we will not be
able to see
whatever the camera will be looking at. NEAR will snap the last
image just
before it reaches the surface," Boynton added.
During its one-year orbiting mission, the NEAR Shoemaker
spacecraft provided
among other data X-ray, gamma ray, and infrared readings on the
composition
and spectral properties of the asteroid. Initial results from the
X-ray
Gamma Ray Spectrometer suggested that Eros might be similar in
elemental
composition to primitive meteorites called chondrites.
"Previously Eros was thought to be a very standard
meteorite, but now it
looks that it might be like a meteorite we've never seen
before. Its
composition might be different than that of typical meteorites.
There might
be some very rare meteorites that resemble Eros, but right now
we're not
sure. We need to wait for another few months for complete
analyses results
to find out, says Boynton, who is the principal investigator for
NEAR's
X-ray Gamma Ray Spectrometer.
"One thing that has been learned from this mission is how to
operate the
spacecraft up close with an irregularly shaped body that has very
little
gravity. Because of its strange shape, the gravity on Eros is not
constant
like it is with a spherical body, such as Earth or Mars.
When one of the
asteroid's lobes comes by, the pull of gravity is greater. It is
very
complicated to take all of these effects into account,"
Boynton explained.
Though the mission has been successful, there are still some
mysteries to be
solved.
"One interesting thing we still don't understand is why
there are some
places which have a lot of very large boulders. They are
unexpected. We
don't see them on the moon. The saddle area is the region where
we see
grooves looking like cracks around Eros, and we are not sure what
caused
them," he said.
Eros almost certainly used to be a piece of a now extinct, bigger
object. At
one time in the past, Eros got knocked off due to a large impact.
The shock
from that event might have left the cracks.
"We don't know when it happened. The space where Eros
resides is crowded
enough to have such collisions today. In order to answer this
question we
would have to land on it, pick up a sample, and bring it back to
Earth for
analysis." Boynton said.
What would he recommend for future asteroid missions?
"If we had the opportunity to do this again, I'd want to
land on the surface
with instruments designed to measure the surface composition and
bring the
samples back," Boynton said.
The UA NEAR team has began archiving the spectra data collected
by
NEAR-Shoemaker and will make them available to other scientists
for
analysis. The task will take about 12 months.
=============
(2) RECIPE FOR SAVING EARTH: MOVE IT
From Space.com, 7 February 2001
http://www.space.com/scienceastronomy/planetearth/earth_move_010207.html
By Robert Roy Britt
Senior Science Writer
Give me a place to stand, and I will move the Earth.
-- Archimedes, circa 235 BC
For a long time now, Earthlings have been threatening to move
heaven and
Earth in order to get this or that accomplished. Politicians
promise to do
so before every election. Moms seem to manage, at least
metaphorically, to
do it every day. Now a group of scientists says it could be done
for real.
Well, heaven might have to stay put. But with existing
technology, some
advance planning and a little orbital energy, courtesy of a
redirected
asteroid, Earth's distance from the Sun could be increased by 50
percent in
just a few billion years.
It's a scheme that could save the planet, at least for a while.
Because if
Earth stays in its current orbit, we are doomed.
Hot death
Just as sure as the Sun comes up every morning, it is scheduled
to die.
Experts give it some 7 billion years, when it will turn into a
bloated red
giant. As the name implies, a red giant is a star swelled to
gargantuan
proportions. Earth would be first engulfed in heat and light,
then
vaporized.
Well before then, things will turn real nasty. In just a billion
years, the
Sun could be 11-percent brighter, scientists say, rendering Earth
an
inhospitable greenhouse. In 3.5 billion years, the Sun could be
40-percent
brighter than it is today.
With our demise so clear on the cosmic horizon, astrophysicist
Fred Adams of
the University of Michigan and NASA's Gregory Laughlin got to
wondering in
recent years how the planet might be saved by gravitational
interaction with
a passing star. They ran computer simulations of possible
encounters over
the next 3.5 billion years, finding last year that the odds of
the Earth
being completely ejected from the solar system are
one-in-100,000.
Slim odds. And life in the frigidity of deep space would be no
summer
picnic.
So Adams and Laughlin, along with Don Korycansky of the
University of
California, Santa Cruz, began to discuss consider how human
intervention
might bring about a more suitable long-term orbit, one that
gradually
expands with the aging Sun.
Their idea, which evolved from interaction with a star to
rerouting a giant
space rock to save Earth, will be published in an upcoming issue
of the
journal Astrophysics and Space Science.
Just an idea
"This is not an urgent problem," Adams stressed, adding
that the researchers
merely wanted to prove -- on paper -- that such a scheme was
possible. "And
we are in no way advocating policy."
Call it mathematical recreation.
After working for years and to determine the fate of the entire
universe --
with results published in the 1999 book, The Five Ages of the
Universe:
Inside the Physics of Eternity -- the researchers spent two weeks
modeling
our escape because, Adams said, scientists and reporters kept
asking, "What
happens to Earth? Is there a way out?"
They started with a simulated comet or asteroid 62 miles (100
kilometers)
wide, about six times larger than the one thought to have killed
off the
dinosaurs 65 million years ago. The solar system has plenty of
objects like
this -- in the main Asteroid Belt between Mars and Jupiter, and
farther out
in the Kuiper Belt. The trick is to find one that's headed our
way, then use
a small amount of energy to guide it, like a spacecraft, onto a
new course
through our solar system.
FULL STORY at
http://www.space.com/scienceastronomy/planetearth/earth_move_010207.html
=========
(3) DEBRIS COLLISION ADVOIDANCE PREDICTIONS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
[From January 2001 issue of ORBITAL DEBRIS QUARTERLY NEWS, NASA
JSC
http://www.orbitaldebris.jsc.nasa.gov/newsletter/v6i1/v6i1-3.html]
Flight Readiness Review Report
By M. Matney
Before every Shuttle mission, the Orbital Debris Program Office
performs a
Flight Readiness Review (FRR) for the mission. Primarily, this
consists of a
detailed analysis of the Shuttle sensitive surfaces with the
Bumper code to
determine the debris and meteoroid risk to the vehicle and
mission. Each
mission has a target risk level that can be altered by the flight
geometry
during the mission. This risk calculation is based on the
standard debris
and meteoroid models and does not take into account short
time-scale
variations in the collision risk. For this reason several
analyses are
performed to estimate any enhancement to the baseline risk for a
particular
mission.
The first source of possible enhancement is that an annual
meteoroid shower
could peak during the mission that might temporarily increase the
net
meteoroid flux over the short two-week Shuttle mission.
Currently, we use a
model of shower activity based on ground observations to compute
a simple
meteoroid flux enhancement factor to be added to the Bumper
results. Because
meteor showers typically last only a few days, it may be possible
to shift
the launch time of a mission to avoid the strongest outbursts of
meteoroid
activity such as a Leonid meteor storm.
The second source of possible enhancement is that the Shuttle
might fly
through a dense region of debris from a recent on-orbit breakup
event. This
could potentially add an enhanced flux onto the time-averaged
ORDEM flux
used by Bumper. The SBRAM code is used each Shuttle mission to
compare all
recent breakups to the future Shuttle orbit to look for potential
debris
cloud enhancements.
During each Shuttle mission, US Space Command performs collision
avoidance
predictions for all catalogued objects in Earth orbit. The
purpose is to
give the Shuttle a warning in case an object is predicted to
enter a
collision warning "box". Currently, this "shoe
box" is 10 km long in
down-track direction, and 4 km wide in radial and cross-track
directions.
NASA is assessing a new "pizza box" that is 14 km wide
in down-range and
cross-track directions, and 2 km wide in the radial direction.
Future
collision avoidance calculations should include more
sophisticated estimates
of the actual estimated position uncertainties computed by Space
Command.
The FRRs are performed some weeks before the actual mission --
too early to
compute actual collision probabilities. However, the flight
directors like a
"heads-up" on the expected number of collision warnings
they may expect for
the mission. For typical Shuttle missions, this number is less
than one, so
that the prediction becomes the probability that a collision
warning will be
issued during this mission. This probability is computed using
the latest
catalog at the time of the FRR using simple estimates of the
collision flux
based on average flux models. We are working on improving our
ability to
make these estimates by using more orbit plane prediction
information.
We are always improving the FRR process, and are also assessing
how we can
provide similar information on a regular basis to the
International Space
Station program in the future.
===========
(4) SPECTAL FEATURES USED TO DETERMINE ORBITAL DEBRIS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
[From January 2001 issue of ORBITAL DEBRIS QUARTERLY NEWS, NASA
JSC
http://www.orbitaldebris.jsc.nasa.gov/newsletter/v6i1/v6i1-3.html]
Spectral Features Used to Determine Material Type of Orbital
Debris
By K. Jorgensen
An ongoing investigation continues on determining the material
type of
small-to medium-sized debris using reflectance spectra features.
Knowledge
of the physical properties of orbital debris is necessary for
modeling the
debris environment. Current methods determine the size and mass
of orbital
debris based on knowledge or assumption of the material type of
the piece.
By using spectroscopy, one can determine the material type of the
piece by comparing
the absorption features of its spectra to that of lab spectra for
given
materials. By isolating three wavelength regions, material types
can be
placed into three main categories: aluminum, other metals, and
plastics.
Using these three categories, one can make better-educated
assumptions of
the material type. The goal of this research is not to improve
the models
themselves, but to improve the information others use to make the
models.
A database of common spacecraft material spectra has been
collected and
contains currently over 300 types of materials. This database
will be used
as a comparison library once observations of orbital debris have
been taken.
The material type will be determined based on comparisons to the
library.
As an example of the absorption features seen on spacecraft
materials,
Figure 1
[ http://www.orbitaldebris.jsc.nasa.gov/newsletter/v6i1/jorgensenfig1.jpg
]
displays three spacecraft materials, aluminum 1100, carbon epoxy,
and steel,
over the same wavelength region. The three wavelength regions
used to
determine material type are 0.5-1.0 µm, 1.5-1.9 µm, and 2.1-2.3
µm. In the
first region, aluminum shows a strong absorption feature near 0.8
µm, which
makes the material easy to pick out when comparing spectra.
Steel, as well
as other metals, tends to show a general increase in slope as
wavelength
increases. Plastics and epoxies of organic nature show absorption
features
due to C-H and/or O-H in the final two regions in the infrared.
Seen in
Figure 1 are absorption features in the carbon material due to
C-H near 1.6
µm and between 2.1 and 2.3 µm.
In order to determine the effects of the space environment on the
reflectance spectra of spacecraft materials, researchers measured
materials
from returned spacecraft. Measurements of material degradation
for returned
missions such as the Long Duration Exposure Facility (LDEF), the
Passive
Optical Sample Assembly I and II (POSA I and II), and the
Evaluation of
Oxygen Interaction with Materials (EOIM-3) were conducted. The
measurements
gave insight to the effect of thermal coatings and paints on the
reflectance
spectra of various materials.
Figure 2 shows a plastic, Polyetheretherketone (PEEK), flown as
part of
experiment number A0171 in experiment tray A8 on LDEF.
[ http://www.orbitaldebris.jsc.nasa.gov/newsletter/v6i1/jorgensenfig2.jpg
]
This sample was obtained from Marshall Space Flight Center
(MSFC);
accompanying the sample was a control piece of PEEK. When
compared to the
control sample the flown sample shows a decrease in the total
reflectance as
seen in Figure 2. A slight discoloration is seen on the exposed
sample near
0.55 µm and was noted visually while testing the sample. A
comparison of the
strengths of the absorption feature in near 1.7 µm shows the C-H
band
decreasing in the flight sample. The feature is still apparent
and still
strong enough to detect through on-orbit observations, but is
definitely not
as strong as it was prior to flight. The C-H features in near 2.1
and 2.35
µm are both the same strength in the control and flight samples.
When the
regions deemed necessary for determining the material type of
orbital debris
through on-orbit spectral measurements are examined, it appears
that the
space environment does not change significantly the absorption
features seen
in plastics in those regions.
When the spectra of returned spacecraft materials were compared
with the
pre-flight laboratory spectra degradation in the samples were
seen mostly in
the visible wavelengths, while the samples showed similar
features in the
near-infrared. Overall, the results displayed less degradation on
the
spaceflight samples than anticipated. The strengths of absorption
features
were relatively the same in pre- and post-flight measurements.
The three
wavelength regions chosen, 0.5 - 1 µm, 1.5 - 1.8 µm, and 2.1 -
2.35 µm were
proven to be viable regions in their ability to determine the
material type
of the spacecraft sample using the absorption features.
The next step in this study is to begin examining of the
reflectance spectra
of debris still in orbit. Along with on-orbit observations, a
continual
building of the spacecraft material database is very important.
As different
paints, plastics, and metals are put onto spacecraft, pre-flight
and
post-flight measurements should be taken. A more detailed study
of the
various coatings would be ideal as well. Currently, the majority
of coatings
placed on the metals have been tested, but the plastics and
paints should be
tested also. Since physical characteristic data on the small- and
medium-sized debris is relatively unknown, any information
obtained on the
material type and thus albedo would help researchers improve
models and
shields. Continued correlation of radar observations and optical
observations coupled with spectral observations would greatly
improve the
knowledge base of physical characteristics of the debris
environment.
============
(5) REMINDER: RAS MEETING TOMORROW ON THE GEOLOGICAL RECORD OF
IMPACTS ON
THE EARTH
From Jacqueline Mitton <aco01@dial.pipex.com>
ROYAL ASTRONOMICAL SOCIETY
PRESS INFORMATION NOTE
Date: 5 February 2001
Ref. PN 02/04
Issued by: Dr Jacqueline Mitton
RAS Press Officer
Office & home phone: Cambridge ((0)1223) 564914
FAX: Cambridge ((0)1223) 572892
E-mail: jmitton@dial.pipex.com
(On the day of the meeting, please use Jacqueline Mitton's mobile
phone
number, 07770 386133.)
RAS Web: http://www.ras.org.uk
THE GEOLOGICAL RECORD OF IMPACTS ON THE EARTH AT ROYAL
ASTRONOMICAL
SOCIETY'S LONDON MEETING ON FEBRUARY 9TH
This one-day discussion meeting in the Royal Astronomical
Society's regular
monthly programme will review and challenge current understanding
of
cratering and impacts throughout the history of the Earth,
setting a context
for possible disaster scenarios in the future, which might
involve comets,
meteorites, or asteroids. There will be contributions on
some of the best
direct geological evidence for impacts, discussions of global
threats,
frequency of impacts, known and potential extinction events, and
the
devastating secondary consequences of impacts, which may include
earthquakes, tsunamis, landslides, and volcano activity. The
keynote talk is
by Christian Koeberl (Vienna), President of the IMPACT
programme of the
European Science Foundation (web site http://ww.esf.org/).
Media representatives are welcome to attend. The meeting is in
the
Geological Society Lecture Theatre at Burlington House,
Piccadilly, London,
W1.
Meeting organisers: Dr Adrian Jones, University College London
(adrian.jones@ucl.ac.uk),
Professor David Price, University College London
(d.price@ucl.ac.uk), and
Dr Monica Grady, Natural History Museum (mmg@nhm.ac.uk).
An outline of the programme is given below.
For more information, contact Dr Adrian Jones
Department of Geological Sciences, University College London,
Gower Street,
London WC1E 6BT
Tel: 0207 679 2415/2408
Fax: 0207 388 7614
email: adrian.jones@ucl.ac.uk
Programme:
10.25-10.30 Introduction by
Chairman, Professor G. David Price,
University College London
10.30-11.00
1 Evidence of the late heavy bombardment
Christian Koeberl (Institute of Geochemistry/Vienna)
11.00-11.20
2 The Chicxulub impact structure: a
review
Mike Warner (Imperial College London)
11.20-11.40
3 ChicxulubII: Nature of the K/T
projectile?
Matthew Genge (Natural History Museum, London)
11.40-12.00
4 Large impacts and impact volcanism?
Adrian Jones (University College London)
12.00-12.20
5 Timing between flood basalts and
impacts.
Simon Kelly (Open University, Milton Keynes)
12.20-12.40
6 Holocene Impacts and the Difficulties
of Detection
Benny Peiser (Liverpool John Moores University)
12.40-12.55
7 Simulation of terrestrial shock
metamorphism
Emma Bowden (University College London)
Afternoon session: (Chair Monica Grady)
14.00-14.15
5 The flux of extraterrestrial material
to the Earth'
Phil Bland (Open University, Milton Keynes)
14.15-14.30
6 NEO-uniformitarianism: are impacts
random in time?
Duncan Steel (University of Salford)
14.30-15.00
7 Regularities in impact records;
possible cometary causes
Bill Napier (Armagh Observatory, Northern Ireland)
15.00-15.15
8 Origin of the K/T Impactor: Comet or
Asteroid?
Mark Bailey (Armagh Observatory, Northern Ireland)
15.15-15.30
9 Microtektites: exoatmospheric
distribution of impact ejecta.
Ralph Lorenz (Lunar Planetary Lab, Arizona)
============================
* LETTERS TO THE MODERATOR *
============================
(6) PERMO-TRIASSIC
From Doug Erwin <Erwin.Doug@NMNH.SI.EDU>
Dear Dr. Peiser,
Relative to Dr. Simonenko's message today, I should remind
participants that
although there is fairly credible evidence of impact associated
with the KT
boundary, there is as yet NO credible evidence of impact
associated with the
Permo-Triassic mass extinction. The paleontologic,
geochronologic and
carbon isotopic data from South China is CONSISTENT with an
impact, but is
also consistent with other scenarios. The Woodleigh
structure in western
Australia is not well dated, and in a recent comment and reply in
Earth and
Planetary Science Letters Mory et al. revealed the structure may
be as old
as Late Devonian - Early Carboniferous. Curiously, a paper
will be
appearing in several weeks with evidence that might suggest a PT
impact, and
it will be interesting to see how the impact community evaluates
this paper.
Best,
Doug Erwin
===========
(7) COSMIC BILLIARDS AND THE PROMOTION OF THE HUMAN RACE
From Matthew Genge <M.Genge@nhm.ac.uk>
Don Korycansky, Gregory Laughlin and Fred Adams have suggested
that the
Earth's orbit could be changed in order to moderate the Earth's
climate. The
technique is relatively simple and, rather worryingly, perfectly
possible
using modern day technology. Just change the orbit of a large
asteroid so that it comes close enough to the Earth to change our
planet's
angular momentum. This technique is nothing new, in fact it was
responsible
for the migration of the planets four and a half billion years
ago whilst
they cleared the solar system of left over planetesimals.
Korycansky,
Laughlin and Adams rather sensibly acknowledge that this would be
a delicate
operation since aiming a huge rock at the Earth does have one or
two minor
risks associated with it. The extinction of 75% of species on the
planet
being one of them. Rather a heafty price to pay for clement
weather.
Using long term propulsion techniques such as mass drivers or
solar sails
the change in the orbit of an asteroid could be achieved very
reliably and,
secular perturbations allowing, the idea would work. There would
be some
small things to check first. Changing the Earth's orbit would
change its
perturbation of the orbits of the other planets, asteroids and
comets and
you would certainly not want to move directly into the path of an
impactor.
It is perhaps this 'safety first' task that is beyond our current
knowledge.
There is, of course, no need to move our planets position in the
solar
system. It would be folly indeed to try and compensate for a
short term
climatic disturbance such as global warming even if we could
reliably
predict how our planet's climate would change after the move.
Only in 4.5
billion years or so when our Sun starts to become a red giant
will the
inhabitants of the Earth perhaps have to think about taking such
drastic
action. It would, in any case, be politically rather difficult
for any
government to unilaterally decide to move the global vegetable
patch to a
sunnier part of the cosmic garden. The chances of all world
governments
agreeing on any course of action being very slim indeed.
Perhaps the most interesting implication of this suggestion is
what it means
for the human race as a whole. The Russian astronomer Nikolai
Kardashev
suggested that civilisations could be classified into four groups
of which
ours is a type 0 civilisation, struggling for survival on a
single planet
that we can't control. The knowledge and the ability to modify
the
configuration of a planetary system to create a more hospitable
and
efficient environment is one of the criteria for a type II
civilisation.
Shifting planets around in a game of cosmic billiards being an
ingenious
alternative to the construction of a Dyson sphere. We now have
the knowledge
and the ability, all we lack is the impetus. In short it appears
the human
race has just been promoted.
____________________
Dr Matthew J. Genge
Researcher (Meteoritics)
Department of Mineralogy, The Natural History Museum
Cromwell Road, London SW7 5BD, UK.
Tel: Int + 020 7 942 5581
Fax: Int.+ 020 7 942 5537
email: M.Genge@nhm.ac.uk
Staff internet page http://www.nhm.ac.uk/mineralogy/genge/genge.htm
==============
(8) A BETTER UNDERSTANDING OF DR. SIMONENKO'S POSITION
From Worth Crouch <doagain@jps.net>
Dear Dr. Peiser,
I am thankful Dr. Vadim Simonenko replied to my inquiries about
difficulties
I had in understanding Russian ideas and projections on asteroid
and
comet/Earth impacts. I was also pleased that E.P. Grondine
in the following
article explained some difficulties he had encountered with
Russian
publications. I concur that another persons language can
often be
misunderstood. Even Voltaire wrote, "Sometimes a man has
nothing more to say
and yet is not persuaded."
After reading Dr. Simonenko's reply to my questions I now
understand that he
doesn't propose some of the messages I concluded from the
SpaceDaily article
that was reproduced. I had the impression that Russian scientists
thought
all the NEO had been discovered. In fact in his reply to me he
writes about
global-scale impactors, "There is the hope that the main
numbers of them
will be discovered before one of them can terminate human
existence"
As far as the threat of Tunguska size asteroids and upwards to
about 300
meters (pardon the American spelling) I think Dr. Simonenko made
it clear
that they do present a considerable threat. Furthermore, he
elaborated on
the size/threat capabilities of different asteroids and I am
secure in the
knowledge that he is aware of the potential of impact
devastation.
Furthermore, even though Dr. Simonenko was reported to have said,
" . .
technology would be able to cope with any danger by finding the
hazardous
object in space and by adopting measures able to prevent its
impact with
Earth." I understand from his explanation that he was
speaking about mankind
's technological future. However, a catastrophe like a
Shoemaker-Levy
9/Earth collision would probably be devastating. Especially when
Dr.
Simonenko writes, "Yes, it is possible that such a
large-scale event can
also happen to our planet. But having even the unexperienced
technology
which exists now, the danger will essentially be discovered
earlier."
The final question that Dr. Simonenko answered revolved around
his saying,
"But global catastrophes occurred only once every 100,000 to
one million years, with
consequences ranging from degradation of the human race to its
total
elimination." I answered his quoted belief by writing,
" . . . the
scientific community only recently deduced the 1908 Tunguska
explosion
resulted from as asteroid impact and scientists were on that
sight almost
immediately. Furthermore, only in that last 30 years has the
credibility of
global catastrophes such as asteroid/comet impacts and massive
volcanic
eruptions been accepted in the scientific community as worthwhile
theories
for ecosystem changes. Therefore, I find it rather presumptuous
to assign
credibility to prehistoric data that at best only approximated
fractionally
what may have actually occurred. Furthermore, when was the
Earth's last
great asteroid collision? I don't think Vadim Simonenko or anyone
has the
data to enable them to forecast an asteroid or comet Earth
collision with
any certainty. In fact because of the mathematical concept of
chaos, even
rainy weather forecasting is imperfect. All that is certain is
that it will
happen." After commenting correctly on the philosophical
nature of much of
my response Dr. Simonenko answered, "As for randomness in
space, it is a
deficiency of our knowledge."
The fact is that understanding randomness in space, it is a
deficiency of
our knowledge and that deficiency has precisely been my point in
questioning
the Russian rational that confidently predicts, " . . .
global catastrophes
occurred only once every 100,000 to one million years . . ."
If Dr.
Simonenko and I can agree that mankind doesn't have the data, and
may not
ever have enough to predict the chaotic randomness of space then
we should
agree that there might not be many generations left to prepare
Earth's
defense for an unexpected collision. Moreover, it is just a
matter of time,
and mankind's deficient ability to understand randomness in
space, until a
space defense is overwhelmed. Consequently, we should not only
defend
ourselves as quickly as possible, but prepare to construct a
place in our
solar system where we can disperse our species and transport the
symbiotic
life that is essential to our existence.
Sincerely,
Worth F. Crouch
(Talako)
==========
(9) PLANETARY DEFENSE
From Andy Smith <astrosafe@yahoo.com>
Hello Benny and CCNet,
We enjoyed the Planetary Defense Special and the associated
Simonenko/Zaitsev/Crouch dialogue, which was enhanced by Ed
Grondine. It is
refreshing to talk about the defensive specifics of this
important challenge
and such positive dialogue is great.
We have been impressed, for some time, with the capabilities of
the
Zenit/Phobos (ZP) system, as a first-line asteroid/comet
planetary
protection system and we want to see plans developed to use such
systems,
quickly, should we have an asteroid/comet emergency (ACE).
Another
first-line system would be the US Delta (Boeing) with a
Clementine Class
spacecraft (CLEMENTINE, NEAR, DEEP IMPACT, DEEP SPACE 1, etc.).
We are now classifying the candidate protective systems in 3
groups, based
on their payload capacity. The Class 1 Systems can carry
spacecraft weighing
1 or 2 tons (deflection energies in the 1 or 2 megaton range).
The Class 2
systems can carry spacecraft in the 5 ton range(5 megatons or
so). Class 3
systems can carry double-digit payloads and deflection devices.
We want to encourage our Russian colleagues to design, now, as
much as
possible of the hardware and software necessary to make this ZP
Asteroid
Deflection System (ZPADS)work...so that it could be employed
quickly, in an
emergency (few days or weeks, instead of months to years). We are
trying to
get the US engineering organizations to do the same thing.
It is especially important to examine all of the issues having to
do with
the mating and operation of the deflection devices....including,
of course,
all of the safety considerations.
One of the objectives of the Planetary Protection Alliance or
Association
(PPA) will be to promote this kind of contingency planning.
Early-Warning Status
The world-wide average NEO discovery rate was at the single-digit
level for
most of the 20th Century. It moved up to double digits in the
last decade or
so and to 3 digits, in the last 3 years....thanks to LINEAR.
Most of the major facilities are now completing major upgrades
(SPACEWATCH,
LONEOS, NEAT, CATALINA) and Bisei is coming on-line. We would
like to see
our Russian colleagues join in this great race.
We are hoping the global discovery rate can reach the 4 digit
output level
before 2005 and that we will have at least one orbiting asteroid
telescope
in operation, in this decade. If we could find 1,000 new NEO per
year, we
could complete most of the hunt (for the 100,000 or so NEO, in
this
Century). 3,000 discoveries per year would bring the total
required
discovery time down to a few decades.
The limiting factor, for the US asteroid hunting facilities,
seems to be
restrictive operating budgets and we are appealing to NASA and
the Congress
to see that the annual national asteroid/comet telescope budget
is
increased, this year, to at least $7 million (or double the
present level).
It is our impression that the $10 million annual funding level
was promised,
in the mid-90's, but only about $3 million per year has been
delivered. We
feel this is a very small price to pay for planetary
security....and
adequate NEO data is the key to a viable planetary defense
progam. At
present, it seems only LINEAR has an adequate operating budget.
There is a detailed discussion of this issue on the Web. It is
associated
with the 1998 Congressional Hearing (Space Science Subcommittee)
and you can
find that on the NASA/Ames Asteroid Hazard Home Page and at
http://www5.onramp.net/~binder/congmethaz.html
We are also optimistic that the Japanese and United Kingdom
programs will be
adequately funded.
The 4 digit annual NEO discovery rate is well within our
grasp....all we
need are modest increases in the operating budgets of these key
facilities.
If all of the concerned countries would build and staff at least
one small
automatic terrestrial asteroid hunting facility (and we could
couple this
with an orbiting system), we could reach the high 4 digit NEO
discovery
level and complete the critical basic data collection effort, in
a few
decades.
Global Planning and Policy Development
Many of the needs identified by Drs. Simonenko and Zaitsev are
very
important. We want to discuss some of them and especially the
international
treaty needs in PPA workshops and report back to the CCNet.
Request for Russian Graphics
If it is possible to post some briefing graphics of the
Zenit/Phobos concept
and the Space Observational Segment (SOS) on the SPACE SHIELD Web
site, we
would like to study them and present the concepts to others, as
part of our
educational/informational outreach
effort.
Cheers
Andy Smith
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