PLEASE NOTE:
*
CCNet 100/2001 - 11 September 2001
---------------------------------
"A University of Arkansas team will work in zero gravity to
test a
sample collector for a proposed NASA mission that one day may
bring
asteroids to Earth from space. The test will be a crucial step in
proposing a NASA space mission called HERA that would collect
samples from
three near-Earth asteroids and return those samples to Earth.
[...] The
collector has two sharp blades made of tungsten carbide that
counter-rotate at various speeds, chopping up small bits of rock
and
sending them flying upwards into the collector -- at least in
theory, a
theory the researchers plan to test on board NASA's KC-135 in
September."
--University Of Arkansas, 10 September 2001
"The amazing little Deep Space 1 probe is now on final
approach to
an extraordinarily risky close encounter of the most exciting
kind
with comet Borrelly. On September 22 it will plunge into the
comet's
coma, the fog of gas and dust expanding away from the nucleus
that
lurks somewhere deep inside. It will attempt to pass within 2000
kilometers
(1250 miles) of the nucleus at about 3:30 pm PDT while traveling
at
16.5 kilometers/second (36,900 miles/hour). The craft will try to
smell,
see, and hear the comet with its instruments, and if it survives
it
will describe its spine-tingling adventures to its anxious human
colleagues elsewhere in the solar system."
-- Marc Rayman, Deep Space 1 Mission Log
"The methods are applied to the study of near-earth
asteroids within
an advanced relativistic NASA model of the solar system with the
ultimate goal of assessing the possibility of collision with
earth. Because
of the relatively large set of initial conditions compatible with
measured
orbit data, great care has to be taken to limit overestimation of
the possible range of final coordinates. [...] This approach
yields
accuracies that are sufficient to guarantee absence-of
collisions."
--M. Berz et al., Verified integration of dynamics in the
solar system
(1) RESEARCHERS TEST ASTEROID COLLECTOR IN ZERO GRAVITY
CONDITIONS
Science Daily Magazine, 10 September 2001
(2) 'KILLER' ELECTRONS AND THE PREDICTION OF SPACE WEATHER
Andrew Yee <ayee@nova.astro.utoronto.ca>
(3) DEEP SPACE 1 MISSION LOG - 9 SEPTEMBER 2001
Ron Baalke <baalke@zagami.jpl.nasa.gov>
(4) DO MINDS PLAY DICE? UNPREDICTABILITY MAY BE BUILT INTO OUR
BRAINS
Nature Science Update, 10 September 2001
(5) NEW METHOD TO CALCULATE ASTEROIDAL DYNAMICS CLAIMS TO HAVE
HIGHER
ACCURACY
M. Berz
(6) DYNAMICS OF SMALL EARTH-APPROACHERS (SEAs)
P. Michel
(7) INTERPRETATION OF LIGHTCURVES OF PRECESSING ASTEROIDS
M. Kaasalainen
(8) RELAXATION OF WOBBLING ASTEROIDS AND COMETS
M. Efroimsky
(9) PROBABLE ASTEROIDAL ORIGIN OF THE TUNGUSKA COSMIC BODY
P. Farinella et al.
(10) EXPLORING THE SITE OF THE TUNGUSKA IMPACT
G. LONGO et al.
(11) GEOPHYSICAL STUDY OF LAKE CLOSE TO TUNGUSKA EPICENTE
L. GASPERINI et al.
(12) DISCOVERY OF PROBABLE TUNGUSKA COSMIC BODY MATERIAL
Q.L. Hou et al.
(13) NO EVIDENCE FOR HIGH CO2/IRIDIUM RATIO IN TUNGUSKA IMPACTOR
A. Jull et al.
(14) MORE ON CO2/IRIDIUM RATIO IN TUNGUSKA IMPACTOR
K.L. Rasmussen et al.
(15) MIRROR, MIRROR ON THE WALL, WHO'S GOT THE WEIRDEST TUNGUSKA
THEORY OF
ALL?
R. Foot
(16) "ACCEPTING OUR FATE"?
Duncan Steel <D.I.Steel@salford.ac.uk>
(17) CHEERS FOR NEAT AND LINEAR
Andy Smith <astrosafe@yahoo.com>
(18) AND FINALLY: UNIVERSE COULD BECOME JELLY, SAYS EXPERT
(REMAINS RETICENT
ON FLAVOUR)
Ananova, 7 September 2001
==================
(1) RESEARCHERS TEST ASTEROID COLLECTOR IN ZERO GRAVITY
CONDITIONS
>From Science Daily Magazine, 10 September 2001
http://www.sciencedaily.com/releases/2001/09/010905074108.htm
Source: University Of Arkansas (http://www.uark.edu)
FAYETTEVILLE, Ark. -- A University of Arkansas team will work in
zero
gravity to test a sample collector for a proposed NASA mission
that one day
may bring asteroids to Earth from space.
The test will be a crucial step in proposing a NASA space mission
called
HERA that would collect samples from three near-Earth asteroids
and return
those samples to Earth.
The test flight will take place the week of Sept. 25 aboard
NASA's KC-135
airplane at Johnson Space Center in Houston. A team led by Derek
Sears,
professor of cosmochemistry and director of the Arkansas-Oklahoma
Center for
Space and Planetary Science, (AOCSPS) will fly for several hours
while the
plane makes parabolic dips in the air, creating pockets of
microgravity
conditions that last for up to 20 seconds. The researchers will
have two
days of flights to test the sample collector, and will experience
microgravity anywhere from 30-40 times on each day.
"The collector is not only the most technically difficult
portion of the
mission. It's the only thing that hasn't been flight tested
before," Sears
said.
Researchers flying on the test mission will include Sears;
Melissa Franzen,
a AOCSPS summer research student from Loras College in Dubuque,
Iowa;
Jeffrey Preble and John DiPalma from SpaceWorks, Inc.; and Paul
Bartlett of
Honeybee Robotics, Inc. Honeybee Robotics recently secured a NASA
contract
to create tools for the next Mars lander. Engineers from Honeybee
designed the
asteroid sample collector, modifying a similar prototype for
comets, which they
had developed some time ago. SpaceWorks, Inc. built the test
fixture that will
enable the collector to be tested on the plane.
The collector has two sharp blades made of tungsten carbide that
counter-rotate
at various speeds, chopping up small bits of rock and sending
them flying upwards
into the collector -- at least in theory, a theory the
researchers plan to test on
board NASA's KC-135 in September.
To test the collector, the researchers need asteroid-like
materials, so
Sears and his colleagues have ordered large bags of concrete,
gravel, sand
and iron filings to create different mixtures for use while in
flight. From
what scientists know about asteroids from images and from
meteorites, Sears
speculates that a mixture of iron, sand and gravel will come
closest to
re-creating an asteroid surface.
The researchers hope to answer several questions through this
flight:
* Does the collector work? Can it transfer material from the
surface to the container?
* How much of the surface material does the collector pick up?
* What's the largest particle the collector can pick up?
* Does the collector physically change the particles (for
example, does it crush them)?
* To what extent does the collector change the composition of the
surface particles?
"We don't want to pick up just the light materials, for
example," Sears
said.
Five people will fly aboard the KC-135 and conduct the
experiments. One
person will work with the samples. The second person will operate
the
cutter. A third person will record everything with a digital
video camera.
And a fourth person will keep records of all the experiments on a
laptop
computer.
The "asteroid" materials will be mixed together in
three different ways -- a
combination of sand and iron filings, a gravel mixture and
concrete -- to
provide a range of possible surfaces that the collector might
encounter in
space.
"We're not optimistic that we can sample concrete,"
Sears said. "But these
materials get to the heart of the really interesting question --
what will
the real asteroid surfaces be like?"
The question has become more pressing in recent years with the
discovery of
hundreds of near-Earth asteroids. These discoveries have caused
an
increasing public concern about asteroid collisions and have
generated
growing scientific interest in asteroid composition.
Scientists can guess at what an asteroid might have in it through
examination of pictures from EROS taken by the Near-Earth
Asteroid
Rendezvous (NEAR) mission or through meteorite data. But
investigations of
actual asteroid pieces would give concrete answers to some of
their
questions.
The proposed HERA mission would use technology derived from the
NEAR mission
to visit three near-Earth asteroids. The spacecraft would then
collect
samples of rocks upon the surface of all three bodies before
returning to
Earth.
An official proposal for the mission could be sent to NASA
sometime next
year, but first the collector must pass another test -- this one
in a vacuum
created by the AOCSPS Andromeda Chamber, a barrel-like collector
that
researchers can use to simulate the conditions of space. Those
tests are
planned for December.
Copyright © 1995-2001 Science Daily Magazine
==============
(2) 'KILLER' ELECTRONS AND THE PREDICTION OF SPACE WEATHER
>From Andrew Yee <ayee@nova.astro.utoronto.ca>
Mullard Space Science Laboratory
University College London
Dorking, UK
Contacts:
Dr. Andrew Coates, ajc@mssl.ucl.ac.uk
phone: 01483 204145 fax: 01483 278312
BA meeting website: www.indigowebdev.com/the-ba/page.asp
MSSL website: www.mssl.ucl.ac.uk
MSSL switchboard: 01483 204100
7 September 2001
Predicting the weather in space
At the British Association for the Advancement of Science meeting
in Glasgow
today, Dr Andrew Coates will unveil some of the new results from
a year-long
study for the satellite insurance industry, via the Tsunami
initiative, on
the effects of space weather on spacecraft. In particular a
web-based
prediction system has been developed to warn of potential danger
for
satellites, using a 'red/amber/green' traffic light system. This
uses real
measured conditions from spacecraft upstream of Earth's magnetic
shield, to
predict the amount of dangerous 'killer electrons' nearer to
Earth over the
following days. The team have found that conditions in the solar
wind give
the best hope for prediction of these potentially damaging
particles. They
are also developing a 'black box' detector for use on commercial
spacecraft.
Space weather produces real problems for humankind and for space
and
ground-based technology although we are shielded from the charged
particle
onslaught by Earth's magnetic field. As well as heat and light,
the Sun
produces a million tonnes per second of solar wind on average.
But the
average picture does not always hold. Events called coronal mass
ejections
fling 10 million megatons of solar material into space, and some
of these
are directed at Earth. When they reach Earth, charged particles
from these
events penetrate Earth's magnetic shield and cause problems for
power
distribution systems, astronauts and satellites. In addition,
solar flares
can send particles towards us at speeds close to the velocity of
light.
These in turn can cause problems for satellites on which we
increasingly
rely for communications, weather forecasting and positioning. The
'killer
electrons' in the Earth's environment are produced when particles
entering
from the solar wind are accelerated to relativistic energies
becoming part
of the radiation belts. The new predictions used by the web-based
system are
of when this process occurs. Other work in MSSL's space plasma
group, which
Dr Coates leads, examines why the acceleration happens
*****
BA presentation
[ http://www.mssl.ucl.ac.uk/pages/news/spaceweather07Sept01/ba2001.htm
]
As well as heat and light, the Sun emits a million tonnes of hot
'solar
wind' per second on average. But the average picture does not
always hold.
During brief 'solar flares' the Sun emits bursts of X- and gamma-
rays, and
sometimes protons and electrons moving near the speed of light
which can
reach Earth in less than an hour. Huge amounts, tens of billions
of tonnes,
of charged solar material from events called 'coronal mass
ejections' can
disrupt the solar wind and buffet Earth's magnetic shield days
later.
Energetic cosmic rays from beyond our solar system can punch
though the
shield too, reaching the Earth's atmosphere. And while we
recently passed
the solar maximum, we are not even safe at the minimum of the
11-year solar
activity cycle.
All of these 'space weather' effects can have important
implications for
humankind. In space, they can cause problems for satellites and
astronauts,
on the ground, power systems can be affected, and in the
atmosphere between,
there are effects on aircraft and on climate. There is much
current interest
in understanding these problems and in predicting when they are
likely to
happen.
The key to predicting space weather events is an understanding of
the
science behind space weather. At the moment space weather
prediction is at
the same state as terrestrial weather prediction was 50 years
ago. To
improve this we need to understand how and why continuous and
impulsive
emissions from the Sun occur. We need to understand how they
propagate
between Sun and Earth, and how our magnetic shield is penetrated.
We need to
understand the effects of solar wind changes on the Earth's
magnetosphere
and radiation belts, where satellites used in our daily lives are
stationed
and where 'killer' relativistic electrons are found. And we need
to
understand the coupling all the way through from the Sun to our
atmosphere.
Now, several international (European, American, Japanese and
Russian)
scientific space missions are studying the chain of events from
Sun to
Earth. Staring at the Sun like SOHO and TRACE, measuring the
upstream solar
wind like ACE and Wind and inside our magnetosphere like Cluster,
Polar and
Geotail, the results are helping us understand the coupling
processes. For
example, the average electrical power incident on the Earth's
magnetic
shield is about 3 million megawatts, equivalent to mankind's
current energy
consumption, corresponding to only 40kg of solar wind material
per second.
Only a few percent of this energy leaks in via 'magnetic
reconnection' -- an
explosive small-scale plasma process which results in magnetic
field being
pulled over Earth's magnetic shield like peeling a banana and
particles
entering along punctures in our shield.
A search for understanding is vital. But we can also use the
knowledge we
have so far to perform applied research and provide forecasting
for specific
problems. For example, at MSSL we are working on practical
applications of
solar and space plasma physics for space weather users. First, we
have two
contracts part funded by the insurance industry as part of the
Tsunami
initiative, one to study satellite failures and the other to
build a 'black
box' detector for commercial satellites. Second, we are working
with Virgin
Atlantic Airways to measure and understand radiation in aircraft
cabins.
In this presentation we will look at four main questions: (1)
what is space
weather? (2) what causes space weather? (3) what effects
does space weather
have? and (4) what are we doing about space weather?
Along the way we will see spectacular movies of the Sun's
effects, look at
the effects of huge solar disturbances including this year's
record solar
flare, look at exciting new results from Cluster and see what is
the 'state
of the art' in space weather prediction. Also, for the first time
in public
we will present results from our work on space environment
prediction and
diagnosis for the satellite insurance industry.
Key finding
The key finding to be presented (although much of the talk is
general) is
that we can, with a reasonable level of skill, predict the
intensity of
'killer' electrons in the Earth's radiation belts using only a
few measured
parameters, and therefore predict and analyse dangerous
conditions for
satellites.
New and interesting
Even after decades of study, only a few aspects of space weather
can be
predicted. 'Killer' electrons can cause danger for satellites on
which we
depend in our daily lives. A new website which can now predict
dangerous
conditions for satellites, using a 'red/amber/green' traffic
light system,
will be unveiled. In addition, new results from Cluster will be
presented
which will help us understand the magnetic shield's response to
space
weather events and we will show results from Cassini which reveal
the
effects of solar activity near Jupiter.
Relevance to general audience
We depend on space for communications, weather forecasting and
positioning
on the Earth's surface. Each applications satellite costs some
$250 million
and is insured. We have an increasing volume of air travel and a
tendency to
use higher altitudes and polar routes. All of these can be
affected by space
weather, making this an important and relevant topic.
Next step
The next step is to improve the skill of predictions and to
broaden the
range of space weather effects that can be predicted.
Others working in area
Many research groups are active in solar and solar-terrestrial
physics (see
RAS MIST webpage at http://www.nerc-bas.ac.uk/public/uasd/mist.html,
solar
groups listed at http://www.mssl.ucl.ac.uk/www_solar/solarlinks.html
). UK
groups are playing lead roles on the SOHO, Cluster and Yohkoh
missions and
are involved in many other space missions and are also strong in
data
interpretation, modelling and theory.
Several UK groups are involved in space weather related work. The
studies at
MSSL involving the insurance industry and airline companies are
particularly
relevant to the BA meeting theme 'Science and Society'.
[NOTE: An image supporting this release is available at
http://www.mssl.ucl.ac.uk/pages/news/spaceweather07Sept01/assets/images/sample_page.JPG
]
================
(3) DEEP SPACE 1 MISSION LOG - 9 SEPTEMBER 2001
>From Ron Baalke <baalke@zagami.jpl.nasa.gov>
http://nmp.jpl.nasa.gov/ds1/mrlog.html
Dr. Marc Rayman's Deep Space 1 Mission Log
Mission Update:
Thank you for visiting the Deep Space 1 mission status
information site,
widely thought of and commonly spoken of in the spiral arms of
the Milky Way
galaxy as the most reliable source of information on this bold
mission of
exploration. This message was logged at 2:00 am Pacific Time on
Sunday,
September 9.
The amazing little Deep Space 1 probe is now on final approach to
an
extraordinarily risky close encounter of the most exciting kind
with comet
Borrelly. On September 22 it will plunge into the comet's coma,
the fog of
gas and dust expanding away from the nucleus that lurks somewhere
deep
inside. It will attempt to pass within 2000 kilometers (1250
miles) of the
nucleus at about 3:30 pm PDT while traveling at 16.5
kilometers/second
(36,900 miles/hour). The craft will try to smell, see, and hear
the comet
with its instruments, and if it survives it will describe its
spine-tingling
adventures to its anxious human colleagues elsewhere in the solar
system.
This log will be updated within a day or two of the encounter or
sooner if
there is important news (and time to report it).
The June 30 and July 29 logs described the measurements to be
undertaken by
devices that are well known to loyal DS1 fans. PEPE, the nose of
the
spacecraft, measures charged particles and will try to reveal the
composition of the gas in the coma and the strange interaction of
the solar
wind with the comet. MICAS, serving as the eyes, contains an
infrared
spectrometer to infer the composition of the nucleus and a black
and white
camera to photograph the nucleus and coma. And taking advantage
of
everything that's on board, the reprogrammed diagnostic sensors
for the ion
propulsion system will serve as the ears, attempting to measure
the magnetic
field and plasma waves in the comet. PEPE and the diagnostic
sensors will
collect data throughout the entire encounter. MICAS will make
measurements
intermittently starting about 1 hour 20 minutes before the
spacecraft makes
its closest passage by the nucleus and concluding a few minutes
before that
time.
But to be honest, DS1's visit with the comet simply is unlikely
to work as
well as we hope. Many mission logs have described the difficulty
of keeping
this aged and wounded bird aloft, and the encounter with Borrelly
will
present Deep Space 1 with the greatest challenge yet in its
historic trek through the solar system. Sometimes it feels to
your
correspondent as if the spacecraft is kept flying with duct tape
and good
wishes! If all the risks for the encounter were listed here, this
log would
be far far too large to download to your computer.
Against such odds, why do we even bother at all? Well, as members
of a
self-respecting space-faring species, how can we not try to do
our best? I
hope you won't be disappointed if we are unsuccessful; of course,
if we
don't try, we are guaranteed not to achieve anything!
One of DS1's objectives will be to photograph the nucleus. But
where is it?
(Urgent note: if you know, please send me an e-mail right away!)
From Earth,
even using the Hubble Space Telescope, the nucleus has never been
directly
observed, as it is shrouded in the secrecy of the obscuring
coma. When DS1 streaks through the coma, it will have to get a
fix on the
nucleus on its own; we can only give it an estimate of the
location. The
July 29 log gave a suggestion of how difficult this is. As a
result of the
rescue following the failure of the star tracker in 1999, the
camera that
has to try to locate the nucleus and try to record images of it
also has to
be used to provide a stable pointing reference for the
spacecraft. These
multifarious responsibilities mean the camera can't be devoted to
performing
any one job completely.
To visualize how accurate the pointing needs to be, suppose MICAS
is at the
center of a clock face and the nucleus is at the 12. If
everything's
perfect, MICAS will point at the 12, just as the hour and minute
hands of
the clock would at 12:00. Now if the pointing is off (either
because the
nucleus is not where the spacecraft thinks it is or because there
is a
pointing problem on the debilitated spacecraft) by an amount
equal to how
far the minute hand moves in 2.5
seconds, it will not get pictures of the nucleus. In other words,
if it
points to where the minute hand is at 12:00:03, it will not see
the nucleus.
And if the pointing is off by only half a second, or 12:00:00.5,
the
infrared measurements will not work.
While many cameras available to amateur photographers
automatically adjust
their exposures to account for how much light reaches them, such
a feature
is not available on most spacecraft. One of the mysteries of the
nucleus is
how bright (or, perhaps more suggestively, how dark) it is, so
choosing
beforehand what exposure to program for the pictures and the
infrared
spectra is an extremely difficult problem. Although a range of
exposures is
planned, the spacecraft will be in the vicinity of the nucleus so
briefly
that there won't be time to take many at all the different
possible values.
We have a few tricks for how to compensate for this, but none of
them is
certain to work.
Many logs have referred to the dwindling supply of hydrazine. The
spacecraft
will die within just a few hours of exhausting that critical
resource, which
was not intended for such a long mission. (In fact, the night
before the
hydrazine was loaded onto the spacecraft, we decided to add a
little extra
and take a bit of a chance with the launch, just in case the
additional
hydrazine might come in handy. Had we not done that, by now DS1
would already have
become just a piece of cosmic flotsam.) Only extraordinary care
by
controllers has stretched the supply this long. Indeed, the whole
ship is
well beyond its planned life.
Let's say DS1's primary mission corresponded to a human lifetime
of 80
years. (Note to editor: before sending this to other planets,
please adjust
these numbers to correspond to the typical lifetimes of the
indigenous
intelligent species.) In that case, it completed all of its
technology
testing when it was 64 -- just about the right time for
retirement. Still
quite spry however, it conducted a bonus encounter with an
asteroid at the
age of 67 before taking it easy. It sailed right through the
equivalent of
its 80th birthday and remained healthy until it was 93. It then
suffered
what should have been a fatal blow, with the loss of its star
tracker. But
the DS1 rescue team eventually completed an amazing recovery,
giving the
veteran adventurer a second chance at life. At the equivalent of
the
incredible age of 149, the rejuvenated DS1 returned to service
and began
heading toward distant Borrelly again. Shortly thereafter, this
Methuselah
set the record for the longest operating time of any propulsion
system on
any spacecraft in history, highly appropriate for an ion
propulsion system
often described as achieving acceleration with patience. When it
reaches
Borrelly, DS1 will correspond to a person 259 years old. The
craft has
certainly lived a full and remarkably productive life!
Keeping DS1 flying smoothly is a difficult (albeit incredibly
neat) job for
the tiny team that is also responsible for planning the comet
encounter. For
example, following the recovery last year, there have been 3
occasions on
which the camera lost lock on its reference star. Two of those
times (in
July 2000 and August 2001) it was the result of unusually strong
solar
storms gusting over the spacecraft and flooding the camera with
radiation. The radiation
registers on the camera's electronic light detector, so instead
of tracking
a single bright star, it appeared that there was a blizzard of
stars, and
the system got confused and ended up pointing in the wrong
direction. The
one other incident, in July 2001, was a consequence of trying to
track a
dimmer star than usual in the presence of the distracting effect
of stray
light that afflicts the camera. In each case, the crack DS1 team
managed to
coax the spacecraft back to its intended configuration, but it is
stressful
and risky work. Now there's nothing quite as neat as having just
half a
dozen space experts, powered in part by Oreo cookies (filled with
chocolate
creme!) in the middle of the night, trying to joystick a
spacecraft two
thirds of a million times farther away than the International
Space Station.
But this illustrates the fragility of the mission at this point;
and another
occurrence of such a problem shortly before the encounter would
eliminate
any chances for images or infrared spectra.
Only one comet nucleus has been glimpsed by a spacecraft before
-- comet
Halley, which was visited in 1986 by several spacecraft,
including the
impressive Giotto. Just as to know humanity it would not be
adequate to meet
only one person (aliens, take note), that one view of Halley is
not sufficient for us to understand the mysteries of comets. The
goal for
imaging on DS1 is to get a picture when the nucleus is about 50
pixels
across (a pixel is the smallest element of the digital camera's
view). This
very difficult objective is unlikely to be achieved for several
reasons
already described and many more. In fact, the spacecraft might
not even
still be operating when it is close enough to get such a picture.
When the probe enters the coma, it will be subjected to a
fusillade of
high-speed debris from the comet. Unlike Giotto, DS1 was not
built to
encounter a comet. As the lowest cost mission into the solar
system yet
undertaken by NASA, no resources could be devoted to anything
other than the
prime mission objectives, so it carries no shielding. When a
single particle
of dust just the thickness of a human hair strikes the
spacecraft, it will
deliver as much energy as a bowling ball does when it crashes
into the pins.
We don't know exactly what the dust environment of the comet is,
but it is
probable that the spacecraft will be hit by a few hundred pieces
of dust of
that size and still larger.
Why not fly farther from the comet so the spacecraft intercepts
much less
dust? This adventure is purely a bonus, coming two years after
the end of
the highly successful primary mission. This isn't the time to be
conservative. As long as we've gone this far, we should take the
chance and
get the most out of this opportunity we can. By flying into the
heart of the
comet, we expose PEPE, the diagnostic sensors, and MICAS to their
best views
of what Borrelly has been hiding for the past 4.6 billion years.
Soon, we'll
know whether DS1 is lucky enough to reveal any of those secrets.
DS1 is now about 19 million kilometers, or 12 million miles, from
comet
Borrelly.
Deep Space 1 is over 1.5 times as far from Earth as the Sun is
and 600 times
as far as the moon. At this distance of 230 million kilometers,
or 143
million miles, radio signals, traveling at the universal limit of
the speed
of light, take 25 and a half minutes to make the round trip.
Thanks again for visiting!
============
(4) DO MINDS PLAY DICE? UNPREDICTABILITY MAY BE BUILT INTO OUR
BRAINS
>From Nature Science Update, 10 September 2001
http://www.nature.com/nsu/010913/010913-7.html
ERICA KLARREICH
Making life-or-death decisions on the toss of a coin is hardly
advisable,
but it happens all the time in our brain's subconscious,
according to new
research. Neurophysiologists have found that clusters of nerve
cells respond
to the same stimulus differently each time, as randomly as heads
or tails.
"It seems that the brain has a gratuitous randomizer, a sort
of cerebral
roulette wheel," said Roger Carpenter of the University of
Cambridge, UK, at
the British Association for the Advancement of Science's annual
meeting in
Glasgow on Friday.
Randomness could be a valuable aid to survival in a complex
world, Carpenter
suggested. "A wildebeest being chased by a lion has a better
chance of
shaking it off if it jumps randomly from right to left," he
said. "And there
are many human activities, for example sports like tennis, in
which it is
desirable to be as unpredictable as possible."
Previously, unexplained variability in the brain's responses was
thought to
be due to 'noise' in incoming stimuli. But then Carpenter and
colleagues
found that the time taken for brain cells to register a flash of
light
varies widely from one flash to the next, between 15 and 35
hundredths of a
second. Added up, the reaction speeds were completely random.
This distribution also showed up in cats, frogs and even
jellyfish.
"Randomness seems to be a fundamental underlying property of
brains,"
Carpenter said.
Now Carpenter's team has found that each tiny packet of brain
cells
randomizes separately from the others. When they flashed two
lights
separated by three hundredths of a second, observers usually
looked at the
light that flashed first, but not always.
The number of times observers chose the later flash exactly
matched what
would be expected to happen if the packets of nerve cells were
processing
the stimuli independently - now and then, randomness would make
the packet
processing the second light fire first.
"If there are several different stimuli, the parts of the
brain processing
them run a race," Carpenter said, claiming that this
independence means that
the brain's reactions are truly unpredictable. "On different
occasions,
changes in the response times will result in different
actions," he said.
Unpredictability in the brain could even be at the root of
creativity,
Carpenter speculated, arguing that "randomness results in
new kinds of
behaviour and combinations of ideas, which are essential to the
process of
discovery".
© Nature News Service / Macmillan Magazines Ltd 2001
===============
(5) NEW METHOD TO CALCULATE ASTEROIDAL DYNAMICS CLAIMS TO HAVE
HIGHER
ACCURACY
Berz M, Makino K, Hoefkens J: Verified integration of dynamics in
the solar
system
NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS 47
(1): 179-190, Part 1
AUG 2001
The motion of objects in the solar system is studied with the use
of
verified integration methods. Providing rigorous bounds for the
possible
coordinates of objects whose initial coordinates are known to lie
in a
certain region, the methods are applied to the study of
near-earth asteroids
within an advanced relativistic NASA model of the solar system
with the
ultimate goal of assessing the possibility of collision with
earth. Because
of the relatively large set of initial conditions compatible with
measured
orbit data, great care has to be taken to limit overestimation of
the
possible range of final coordinates. This is achieved using the
approach of
Taylor models. Within this framework, it is possible to control
the
so-called dependency problem as well as the wrapping effect
commonly
observed in verified integration. This approach yields accuracies
that are
sufficient to guarantee absence-of collisions. Examples of orbit
integrations are given, showing that even relatively large domain
boxes can
be transported over extended time periods with a relative
overestimation in
the range of only around 10(-5).
Addresses:
Berz M, Michigan State Univ, Dept Phys & Astron, E Lansing,
MI 48824 USA
Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824
USA
Michigan State Univ, Natl Superconducting Cyclotron Lab, E
Lansing, MI 48824
USA
Copyright © 2001 Institute for Scientific Information
==============
(6) DYNAMICS OF SMALL EARTH-APPROACHERS (SEAs)
Michel P, Froeschle C: Dynamics of small earth-approachers on
low-eccentricity orbits and implications for their origins
CELESTIAL MECHANICS & DYNAMICAL ASTRONOMY 78 (1-4): 93-112
2000
The population of Near-Earth Asteroids (NEAs) appears to be
overabundant at
sizes smaller than 50m, compared to a power-law extrapolation
from
kilometer-sized objects. Several of these small NEAs are also
concentrated
on low-eccentricity orbits, where a few larger Earth-crossers are
observed,
and are called Small Earth-Approachers (SEAs). Their source
region as well
as the dynamical mechanisms involved in their transport close to
the Earth
on low-eccentricity orbits have not yet been determined. In this
paper, we
present our numerical and statistical study of the production and
dynamical
evolution of these SEAs. We first show that three main sources of
Earth-crossers which are, according to recent simulations, the
3/1 and v(6)
resonances in the main belt, and the Mars-crosser population, are
not able
to produce as many bodies on SEAs-like orbits compared to other
Earth-crossing orbits as has been inferred from observations.
From these
sources, SEAs-like orbits are reached through the interplay of
two required
mechanisms: secular resonances and planetary close approaches.
However, the
time spent on these orbits remains smaller than I Myr as
confirmed by the
study of the evolutions of 11 observed SEAs which also reveal the
action of
various mechanisms such as close approaches to planets and/or
secular
resonances. Therefore, our results present some mechanisms which
can be
responsible for their production but none that would preserve the
lifetime
of the SEAs sufficiently to enhance their abundance relative to
other
Earth-crossing orbits at the level observed. The overabundance of
the SEA
population, if real, remains a problem and could be related to
the influence
of collisional disruption and tidal splitting of Earth-crossers,
as well as
to observational biases that might account for a discrepancy
between theory
and observation.
Addresses:
Michel P, Observ Cote Azur, BP 4229, F-06304 Nice 4, France
Observ Cote Azur, F-06304 Nice 4, France
Copyright © 2001 Institute for Scientific Information
============
(7) INTERPRETATION OF LIGHTCURVES OF PRECESSING ASTEROIDS
Kaasalainen M: Interpretation of lightcurves of precessing
asteroids
ASTRONOMY & ASTROPHYSICS 376 (1): 302-309 SEP 2001
I show that the lightcurves of freely precessing asteroids can be
analyzed
using basically the same methods as with objects in relaxed
rotation. At
least two different observation geometries (with respect to the
angular
momentum vector) are needed for a unique full solution; an
informative basic
model can be constructed at only one geometry, if the
observations span
several precession cycles. Even noisy data yield a good estimate
of the
dynamical parameters, whereas accurate data are required for a
good shape
solution.
Addresses:
Kaasalainen M, Univ Helsinki Observ, POB 14, Helsinki 00014,
Finland
Univ Helsinki Observ, Helsinki 00014, Finland
Copyright © 2001 Institute for Scientific Information
=============
(8) RELAXATION OF WOBBLING ASTEROIDS AND COMETS
Efroimsky M: Relaxation of wobbling asteroids and comets -
theoretical
problems, perspectives of experimental observation
PLANETARY AND SPACE SCIENCE 49 (9): 937-955 AUG 2001
A body dissipates energy when it freely rotates about any axis
different
from principal. This entails relaxation, i.e., decrease of the
rotational
energy, with the angular momentum preserved. The spin about the
major-inertia axis corresponds to the minimal kinetic energy, for
a fixed
angular momentum. Thence one may expect comets and asteroids (as
well as
spacecraft or cosmic-dust granules) to stay in this, so-called
principal,
state of rotation, unless they are forced out of this state by a
collision,
or a tidal interaction, or cometary jetting, or by whatever other
reason. As
is well known, comet P/Halley, asteroid 4179 Toutatis, and some
other small
bodies exhibit very complex rotational motions attributed to
these objects
being in non-principal states of spin. Most probably, the
asteroid and
cometary wobble is quite a generic phenomenon. The theory of
wobble with
internal dissipation has not been fully developed as yet. In this
article we
demonstrate that in some spin states the effectiveness of the
inelastic-dissipation process is several orders of magnitude
higher than
believed previously, and can be measured, by the presently
available
observational instruments, within approximately a year span. We
also show
that in some other spin states both the precession and
precession-relaxation
processes slow down considerably. (We call it near-separatrix
lingering
effect.) Such spin states may evolve so slowly that they can
mimic the
principal-rotation state. (C) 2001 Elsevier Science Ltd. All
rights
reserved.
Addresses:
Efroimsky M, Harvard Univ, Dept Phys, Cambridge, MA 02138 USA
Harvard Univ, Dept Phys, Cambridge, MA 02138 USA
Copyright © 2001 Institute for Scientific Information
===============
(9) PROBABLE ASTEROIDAL ORIGIN OF THE TUNGUSKA COSMIC BODY
>From http://www-th.bo.infn.it/tunguska/H2886.pdf
P. Farinella1, L. Foschini2, Ch. Froeschle3, R.Gonczi3, T.J.
Jopek4, G.
Longo5;6 and P. Michel 3
1Dipartimento di Astronomia, Universite a di Trieste, Via Tiepolo
11, 34131
Trieste, Italy
2Istituto TeSRE { CNR, Via Gobetti 101, 40129 Bologna, Italy
3Observatoire de la Cote d'Azur, Departement Cassini, URA CNRS
1362, B.P.
229, 06304 Nice, France
4Obserwatorium Astronomiczne Universytetu A. Mickiewicza,
Sloneczna 36,
60286 Poznan, Poland
5Dipartimento di Fisica, Universite a di Bologna, Via Irnerio 46,
40126
Bologna, Italy
6INFN, Sezione di Bologna, Via Irnerio 46, 40126 Bologna, Italy
Accepted for the publication in Astronomy and Astrophysics
Received 16 May 2001; Accepted 23 July 2001
Abstract. The complete characterisation of the Tunguska event of
30th June
1908 is still a challenge for astrophysicists. We studied the
huge amount of
scientific literature to select data directly available from
measurements
and we introduced parameters calculated by the application of
models, and
evaluated other possibilities. We then selected a range of
meaningful
atmospheric trajectories, from which we extracted a set of
possible orbits.
We obtained 886 orbits, which were used to estimate the
probabilities of the
possible origin of the Tunguska Cosmic Body (TCB). We found that
the
probability that the TCB moved on an asteroidal path is higher
than it moved
on a cometary one, 83% to 17%, respectively.
FULL PAPER at http://www-th.bo.infn.it/tunguska/H2886.pdf
==============
(10) EXPLORING THE SITE OF THE TUNGUSKA IMPACT
>From http://www-th.bo.infn.it/tunguska/Longo_Abstract_full_ref.doc
GIUSEPPE LONGO1, ENRICO BONATTI2, MARIO DI MARTINO3, LUIGI
FOSCHINI4, LUCA
GASPERINI2
1 Dipartimento di Fisica and INFN, via Irnerio 46, I-40126
Bologna,Italy,
longo@bo.infn.it
2 Istituto di Geologia Marina, CNR, via Gobetti 101, I-40129,
Bologna,
Italy, lucag@igm.bo.cnr.it
3 Osservatorio Astronomico di Torino, I-10025 Pino Torinese,
Italy
dimartino@to.astro.it
4 Istituto TeSRE, CNR, via Gobetti 101, I-40129, Bologna, Italy,
foschini@tesre.bo.cnr.it
1.The Tunguska event is the largest cosmic calamity caused by the
impact of
an interplanetary body with the Earth atmosphere that happened
during
historical times.
A two-week scientific expedition (Tunguska99,
http://www-th.bo.infn.it/tunguska/)
to the impact site has been carried out
starting from 14 July 1999 by the Department of Physics of the
University of
Bologna, in collaboration with researchers of the Turin
Astronomical
Observatory and of the Institute of Marine Geology (CNR
Bologna). A camp
was built in the taiga, at some hundred kilometers from the
nearest roads.
Personnel and researchers, mainly from Tomsk (Russia), provided
local
support. The participants and the equipment were transported from
Italy to
Krasnoyarsk by a Russian Iljushin IL-20M aircraft of the GosNIIAS
Institute
and from Krasnoyarsk to Tunguska by a Russian MI-26 helicopter.
The main
goal of the expedition was to carry out a systematic exploration
of the
impact site, in order to assess the nature of the body that
caused the
devastation, felling more than 80 million trees. The explosion
occurred at a
height of 5-10 km, releasing energy between 10 and 20 million
Megatons.
Neither macroscopic fragments of the cosmic body, nor a typical
signature of
an impact, like a crater, have been found. In spite of the vast
amount of
theoretical and experimental work done up to now (Vasilyev V.N.,
1998 and
references therein), the nature and composition of the cosmic
body and the
dynamics of the event have not yet been clarified. Some, but no
conclusive,
data were acquired by the first Italian 1991 expedition (Longo et
al., 1994;
Serra et al., 1994). The "Tunguska99" expedition
(Amaroli et al., 2000) was
organized in order to give an answer about the origin of the
Tunguska event,
and a contribution to the international research programs aiming
at the
study of cosmic impacts with the Earth. The main tasks of the
"Tunguska99"
expedition were: 1) to study the structure and sediments of the
lake Cheko;
2) to carry out a multispectral (from visible to medium infrared)
aerial
photosurvey of the explosion site; 3) to collect peat, rock and
wood
samples; 4) to monitor gamma rays during the flights
Italy-Siberia-Italy and
in Tunguska. The samples and data collected during the expedition
are now
under examination in different Italian laboratories. The
aim of these
analyses is to deduce important characteristics of the Tunguska
event and to
refine, verifying their accuracy, the mathematical models
concerning the
impacts with atmosphere of cosmic bodies having different
composition and
dimensions.
FULL PAPER at http://www-th.bo.infn.it/tunguska/Longo_Abstract_full_ref.doc
===========
(11) GEOPHYSICAL STUDY OF LAKE CLOSE TO TUNGUSKA EPICENTE
>From http://www-th.bo.infn.it/tunguska/gasperini_et_al.rtf
Geophysical/sedimentological study of a lake close to the
epicenter of the
great 1908 Siberian (Tunguska) explosion.
L. GASPERINI1, F. ALVISI1, G. BIASINI2, E. BONATTI1, M. DI
MARTINO3, C.
MORIGI1, G. LONGO4, M. PIPAN5, M. RAVAIOLI1, F. SACCHETTI1, M.
SACCHI6,
L.VIGLIOTTI1.
1 Istituto di Geologia Marina, CNR, Bologna, Italy.
2 Communication Technology, Cesena (FC), Italy.
3 Osservatorio Astronomico di Torino, Torino, Italy.
4 Dipartimento di Fisica, Universita' di Bologna, Bologna, Italy.
5 Dipartimento di Scienze della Terra, Univ. di Trieste, Trieste,
Italy.
6 Istituto Geomare Sud, CNR, Napoli, Italy.
Corresponding Author:
Luca Gasperini, Istituto di Geologia Marina, CNR, via Gobetti
101, 40129,
Bologna, Italy.
Ph.: +39-051-6398910
Fax: +39-051-6398940
Email: lucag@igm.bo.cnr.it
A scientific expedition took place in July 1999 in the region of
Tunguska
(Siberia). The objective (Longo et al., this volume) was to
gather data that
could help understand the so called "Tunguska event",
namely, an explosion
that on June 30 1908 devastated over 2000 square km of Siberian
Taiga.
Several hypotheses have been put forward to explain the Tunguska
event. Most
assume the explosion in the atmosphere of a small asteroid or
comet.
However, fragments of the cosmic body have not been found to
date, although
several data (including iridium anomalies in peat deposits)
support a cosmic
impact hypothesis (Longo et al.,1994; Kolesnikov et al., 1999).
One of the
main tasks of the 1999 expedition was a
geophysical/sedimentological study
of lake Cheko, a small (~ 500m diameter) lake located 8 km from
the inferred
epicenter of the Tunguska event (Florenskij, 1963; Fast et al.,
1967). An
inflatable catamaran was used both for the geophysical survey,
and for the
coring operations. Our work had two main objectives: 1) to check
whether or
not the lake fills an impact crater related to the event; 2) if
the lake is
not an impact crater related to the 1908 event, to detect in the
lake
sediments mineralogical, chemical and biological evidence on the
nature of
the cosmic body.
FULL PAPER at http://www-th.bo.infn.it/tunguska/gasperini_et_al.rtf
===========
(12) DISCOVERY OF PROBABLE TUNGUSKA COSMIC BODY MATERIAL
Hou QL, Kolesnikov EM, Xie LW, Zhou MF, Sun M, Kolesnikova NV:
Discovery of
probable Tunguska cosmic body material: anomalies of platinum
group elements
and rare-earth elements in peat near the Explosion Site (1908)
PLANETARY AND SPACE SCIENCE 48 (15): 1447-1455 DEC 2000
Ten Spagnum fuscum peat samples collected from different depths
of a core
including the layer affected by the 1908 Tunguska explosion in
the Tunguska
area of Central Siberia, Russia, were analyzed by ICP-MS to
determine the
concentrations of Pd, Rh, Ru, Co, REE, Y, Sr, and Sc. The
analytical results
indicate that the Pd and Rh concentrations in the event- and
lower layers
were 14.0-19.9, and 1.23-1.56 ppb, respectively, about 3-9 times
and 3 times
higher than the background values in the normal layers. In
addition, the
patterns of CI-chondrite-normalized REE in the event layers were
much
flatter than in the normal layers, and differed from those in the
nearby
traps. Hence, it can be inferred from the characteristics of the
elemental
geochemistry that the explosion was probably associated with
extraterrestrial material, and which, most probably, was a small
comet core
the dust fraction of which was chemically similar to carbonaceous
chondrites
(CI). In terms of the Pd and REE excess fluxes in the explosion
area, it can
be estimated that the celestial body that exploded over Tunguska
in 1908
weighed more than 10(6) t, corresponding to a radius of > 60
m. If the
celestial body was a comet, then its total mass was more than 2 x
10(7) t,
and it had > 160 m radius, and released an energy of >
10(7) t TNT. (C) 2000
Elsevier Science Ltd. All rights reserved.
Addresses:
Hou QL, Chinese Acad Sci, Inst Geol & Geophys, Lab
Lithosphere Tecton
Evolut, POB 9825, Beijing 100029, Peoples R China
Chinese Acad Sci, Inst Geol & Geophys, Lab Lithosphere Tecton
Evolut,
Beijing 100029, Peoples R China
Univ Hong Kong, Dept Earth Sci, Hong Kong, Hong Kong, Peoples R
China
Moscow MV Lomonosov State Univ, Geol Fac, Moscow 119899, Russia
Copyright © 2001 Institute for Scientific Information
==============
(13) NO EVIDENCE FOR HIGH CO2/IRIDIUM RATIO IN TUNGUSKA IMPACTOR
Jull AJT, Burr GS, Kring DA: Comment on "Evidence for a very
high
carbon/iridium ratio in the Tunguska impactor" by K. L.
Rasmussen, H. J. F.
Olsen, R. Gwozdz and E. M. Kolesnikov
METEORITICS & PLANETARY SCIENCE 36 (7): 999-1001 JUL 2001
We discuss possible evidence for a dilution of C-14 caused by the
Tunguska
impact event, proposed by Rasmussen et al. (1999). The results
presented in
that paper and other available information do not support this
hypothesis.
Addresses:
Jull AJT, Univ Arizona, NSF, Arizona AMS Lab, Tucson, AZ 85721
USA
Univ Arizona, NSF, Arizona AMS Lab, Tucson, AZ 85721 USA
Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA
Copyright © 2001 Institute for Scientific Information
=============
(14) MORE ON CO2/IRIDIUM RATIO IN TUNGUSKA IMPACTOR
Rasmussen KL, Olsen HJF, Gwozdz R, Kolesnikov EM: Comment on
"Evidence for a
very high carbon/iridium ratio in the Tunguska impactor" by
K. L. Rasmussen,
H. J. F. Olsen, R. Gwozdz and E. M. Kolesnikov - Authors' reply
METEORITICS & PLANETARY SCIENCE 36 (7): 1001-1006 JUL 2001
Jull et al. propose an alternative interpretation of our depth
vs. C-14 data
measured on a peat core from the central Tunguska impact site
(Rasmussen et
al., 1999). We find that the proposed alternative is untenable.
Addresses:
Rasmussen KL, Natl Museum Denmark, Radiocarbon Lab, Ny Vestergade
11,
DK-1471 Copenhagen K, Denmark
Natl Museum Denmark, Radiocarbon Lab, DK-1471 Copenhagen K,
Denmark
TraceChem, DK-2300 Copenhagen, Denmark
Moscow MV Lomonosov State Univ, Dept Geol, Moscow 119899, Russia
Copyright © 2001 Institute for Scientific Information
===========
(15) MIRROR, MIRROR ON THE WALL, WHO'S GOT THE WEIRDEST TUNGUSKA
THEORY OF
ALL?
Foot R: Seven (and a half) reasons to believe in mirror matter:
From
neutrino puzzles to the inferred dark matter in the universe
ACTA PHYSICA POLONICA B 32 (7-8): 2253-2269 JUL-AUG 2001
Parity and time reversal are obvious and plausible candidates for
fundamental symmetries of nature. Hypothesising that these
symmetries exist
implies the existence of a new form of matter, called mirror
matter. The
mirror matter theory (or exact parity model) makes four main
predictions:
(1) Dark matter in the form of mirror matter should exist in the
Universe
(i.e. mirror galaxies, stars, planets, meteoroids...), (2)
Maximal ordinary
neutrino-mirror neutrino oscillations if neutrinos have mass, (3)
Orthopositronium should have a shorter effective lifetime than
predicted by
QED (in "vacuum" experiments) because of the effects of
photon-mirror photon
mixing and (4) Higgs production and decay rate should be 50%
lower than in
the standard model due to Higgs mirror-Higgs mixing (assuming
that the
separation of the Higgs masses is larger than their decay
widths). At the
present time there is strong experimental/observational evidence
supporting
the first three of these predictions, while the fourth one is not
tested yet
because the Higgs boson, predicted in the standard model of
particle
physics, is yet to be found. This experimental/observational
evidence is
rich and varied ranging from the atmospheric and solar neutrino
deficits,
MACHO gravitational micro-lensing events, strange properties of
extra-solar
planets, the existence of "isolated" planets,
orthopositronium lifetime
anomaly, Tunguska and other strange "meteor" events
including perhaps, the
origin of the moon. The purpose of this article is to provide a
not too
technical review of these ideas along with some new results.
Addresses:
Foot R, Univ Melbourne, Sch Phys, High Energy Phys Res Ctr,
Melbourne, Vic
3010, Australia
Univ Melbourne, Sch Phys, High Energy Phys Res Ctr, Melbourne,
Vic 3010,
Australia
Copyright © 2001 Institute for Scientific Information
============================
* LETTERS TO THE MODERATOR *
============================
(16) "ACCEPTING OUR FATE"?
>From Duncan Steel <D.I.Steel@salford.ac.uk>
Dear Benny,
I'd like to express my appreciation of the newspaper article by
Lord David
Howell which was carried on CCNet (10 September). He is entirely
correct to
point out that nowadays we tend to worry about disaster scenarios
which, in
the past, people accepted as being undesirable but
unavoidable features of life, along with the many other ills that
have
plagued people for most of human history. Things like infant
mortality,
typhoid epidemics from unclean water, and poverty levels forcing
widows and
orphans into the workhouse, or worse. In many parts of the world
these conditions still prevail, and obviously the people are
happier for it.
Myself I look back fondly on my childhood, when polio-struck
children could
still be seen gaily playing in the street, clumping along in
their calipers.
We have been all too quick to accept the gifts of science without
questioning whether they are truly benefits. Take extinctions,
for example.
One could mention an organism that humankind has ruthlessly and
willfully
exterminated, until now it no longer exists in its natural state,
and is
limited to a few colonies kept in captivity. Perhaps it should be
re-released into the wild. I refer, of course, to the smallpox
virus.
Similarly bacteria have rights, and so we should ban the use of
expensive
antibiotics. Then we could go back to worrying about diseases and
infections, rather than volcanoes, earthquakes, storms, floods
and
asteroids, which are much lesser threats.
We should be more accepting of our fate, and go quietly.
Duncan Steel
================
(17) CHEERS FOR NEAT AND LINEAR
>From Andy Smith <astrosafe@yahoo.com>
Hi Benny and CCNet,
It is just terrific to see NEAT reporting such great new NEO data
and to see
LINEAR back on the track (post-monsoon). The month of August
closed with
excellent results. There were about 43 NEO
discoveries. Each team found about 40% of the total. About 80% of
the
discoveries were smaller than a kilometer.
If it is possible for the six existing teams to operate at the
level
demonstrated by these two teams (last month), the global
discovery rate
could pass 1,000 NEO discoveries a year, in the near future.
Much, of
course, will depend upon the adequacy of their operating funds.
The Dark-Matter Telescope (DMT) or Large Synoptic Survey
Telescope (LSST)
design is progressing, we understand....and that super-system (8
meters)
could possibly speed-up the discovery rate by a factor of 10 and
reduce the
period-of-great-uncertainty (PGU) from a few centuries to a
decade or two.
The Race of Races
It is clearly a race, Benny....a race between us and that next
rock....and
many of our critics may not be fully aware of the odds. The
chance of
another Tunguska (or Barringer) is about 1 in 100, per
year!!!!....an
alarmingly high-risk, in the light of the possible consequences.
Of course, 70% of the time, the rock will hit in water...but that
is no
consolation, because of the tsunami threat to the coastal cities.
It is always also important to note that our generation is the
first one, in
human history, to have the technology and the tools needed (and
on the
shelf), to protect the future of humanity. We have no excuse for
failing to
act.....and both the dead and the unborn are looking to us.
Here's To Our Search Teams
We continue to applaud our search teams and excellent data-base
managers
(MPC and NEODYS), for their dedication to the task. Pehaps,
again, the many
owe a tremendous debt to the few.
We are also looking forward to a major search effort, from the
Japanese team
(thanks to SPACEGUARD/JAPAN) and we wish them the best, as they
dedicate
their new facility, in a few weeks, and host a meeting to enhance
global
search effectiveness.
Finally, it's !!here-here!! for Duncan Steele and his excellent
articles and
the coverage they receive....and to CCNet for reporting the
coverage.
We are promoting the notion of the DMT/LSST as an international
program, in
the spirit of the U.K. Parliamentary resolution. It is important
to do all
we can to speed-up that effort and this might be one way to do
it. As soon
as we learn more about the funding plans, we will advise the Net.
Finally, we ask everyone to push to get the existing large survey
telescopes
to help us.
Cheers
Andy Smith
===============
(18) AND FINALLY: UNIVERSE COULD BECOME JELLY, SAYS EXPERT
(REMAINS RETICENT
ON FLAVOUR THOUGH)
>From Ananova, 7 September 2001
http://www.ananova.com/news/story/sm_391772.html?menu=news.scienceanddiscovery.amazingscience
A scientist says the Universe and everything in it could one day
turn to
jelly. But he says the probability of it happening is so small
that we might
as well not worry about it.
Dr Benjamin Allanach, an expert in particle physics, says the
likelihood is
about one in 169 million million.
His theory is based on the idea of super-symmetry which says
every particle
has a heavier partner with similar but not identical properties.
He says there is a chance of a jelly-like substance associated
with the
partners of the smallest known particles spontaneously appearing.
If it ever happens the laws of physics and the whole nature of
the Universe
would change.
Dr Allanach, from the European laboratory for particle physics,
CERN, in
Geneva, told the British Association Festival of Science in
Glasgow the
Universe "could suddenly condense into jelly".
He added: "This would happen in one point in the universe
and it would
spread out at the speed of light, disintegrating everything, even
changing
the particles of the nuclei in the atoms that are in the path of
this
expanding sphere."
Copyright 2001, Ananova
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