PLEASE NOTE:
*
CCNet 138/2002 - 26 November 2002
---------------------------------
"The day will arrive when an asteroid is discovered on a
collision
course with Earth. The more we know about their orbit and
structure, the
more effective we can be in attempting to deflect it from harm's
way."
--Commission on the Future of the U.S. Aerospace Industry
"All right so how soon is there a likelihood of a crashing
asteroid?
The question reminds me of the American scientist who first
discovered
that our human eyes were beginning to grow closer together, which
provoked
the response from the late Robert Benchley: "My eyes are so
close
together as it is, I bet I make it - I bet I'm the first one-eyed
man in the
world." Happily the answer from NASA is the same as the
answer from the eye
specialist. "Soon", they say, could mean possibly this
century, more
likely through the next millennium or even beyond."
--Alistair Cooke, BBC Online, 25 November 2002
(1) ASTRONOMERS HUNT FOR KILLER ASTEROIDS
The Detroit News, 26 November 2002
(2) A CALL FOR PLANETARY DEFENSE
Space.com, 25 November 2002
(3) ALISTAIR COOKE'S LETTER FROM AMERICA: "ARMAGEDDON CAN
WAIT"
BBC Online, 25 November 2002
(4) SCIENTISTS HURL ROCKS TO STUDY SPACE BACTERIA
The Daily Camera, 25 November, 2002
(5) WHY IS EVERYONE FORGETTING THE IMPACT OF COMETS?, OR,
REALLY BIG NEWS:
COMET SHOEMAKER-LEVY 9 HITS JUPITER
E.P. Grondine <epgrondine@hotmail.com>
(6) AND FINALLY: "ASTEROID DANGER DISCOUNTED"
The Washington Post, 25 November 2002
=============
(1) ASTRONOMERS HUNT FOR KILLER ASTEROIDS
>From The Detroit News, 26 November 2002
http://www.detnews.com/2002/technology/0211/26/a02-20707.htm
About 600 have been identified so far, report says
By Robert Cooke / Newsday
WASHINGTON -- Like prisoners trying to identify snipers taking
aim,
astronomers are spotting more and more chunks of rock in the sky
that may
yet whack us.
As of last year, according to a report in Sky & Telescope
magazine,
observers had already found about 600 asteroids that are half a
mile in
diameter, or bigger, capable of causing enormous damage on impact
with
Earth. Many have a chance of hitting the Earth -- sometime.
More recently, an estimate of how often smaller objects --
asteroids only 50
yards in diameter -- hit Earth's atmosphere was revised downward
by
astronomers in Canada and the United States.
Objects of that size probably arrive, on average, once every
1,000 years,
not every 200 to 300 years, in light of eight years of
observations.
Such asteroids are small enough so they tend to explode at high
altitude,
but their shock waves sometimes reach the ground, as in the
Tunguska event
in Siberia in 1908. That shock flattened a forest for miles
around, even
though the asteroid never hit the ground.
As for the really big objects, those half a mile or more in
diameter, the
latest estimates, by J. Scott Stuart at the Lincoln Laboratory in
Bedford,
Mass., suggest 1,250 such asteroids exist. And some of them are
in orbits
that may yet send them smashing into the Earth.
The 600 or so already identified near Earth asteroids have
actually been
seen and catalogued, unlike many of the smaller asteroids, which
are harder
to see.
Although impacts by the very large objects are rare, occurring
roughly once
every 100,000 years, they are extreme events indeed, and one
would be
capable now of erasing much of what civilization has created.
Scientists think an explosive impact would touch off massive
fires,
windstorms, seismic sea waves and dust clouds that might last for
weeks or
months. The disruption could be global and long-lasting.
A search of the skies has since turned up about 600 of the big
ones, and
some astronomers think there may be twice as many, with half yet
unseen.
Copyright 2002, The Detroit News
=============
(2) A CALL FOR PLANETARY DEFENSE
>From Space.com, 25 November 2002
http://space.com/news/astronotes-1.html
The final report of the Commission on the Future of the U.S.
Aerospace
Industry, released last week, calls for the Department of Defense
(DoD) to
take on the role of planetary defense.
The Commission noted that the U.S. Air Force is looking into use
of
satellites for detecting and tracking human-made satellites in
Earth orbit.
That effort should be broadened, the study group advised, to
include
detection of asteroids.
Given Air Force study and other military space reviews underway,
"planetary
defense should be assigned to the DoD in cooperation with
NASA," the report
states.
"The day will arrive when an asteroid is discovered on a
collision course
with Earth. The more we know about their orbit and structure, the
more
effective we can be in attempting to deflect it from harm's
way," the
Commission report concludes.
-- Leonard David
===========
(3) ALISTAIR COOKE'S LETTER FROM AMERICA: "ARMAGEDDON CAN
WAIT"
>From BBC Online, 25 November 2002
http://news.bbc.co.uk/1/hi/world/letter_from_america/2510595.stm
In a recent letter I remarked on the striking - to me -
resemblance of the
events of the past year or so to the chronicles of the Bible, or
I should
say of the prophetic books that warn us what's in store for
wicked people
everywhere.
I'm thinking of the apocalyptic sequence of worldwide floods and
fires,
earthquakes, terrorist eruptions and the one doomsday hour 14
months ago -
that plume of brimstone, which we learned in childhood is the
fuel of
hellfire.
Well two or three things have happened recently, two of which
stress the
warnings but a third which suggests that we may yet be saved.
Last week a couple arrived in New York city from New Mexico and
within 24
hours were in a hospital being treated for - wait for it -
bubonic plague.
If we had, which happily we don't, a national daily tabloid what
a feast day
they'd have had of it - "Bubonic Plague Strikes New
York!"
Two days later there was a dispatch from out west - from Los
Angeles.
I quote: "A plague has descended from the sky, a rare and
frightening thing.
People are dying on the highways, planes are falling out of the
sky, the
hills are sliding into the city, cell phones have gone to static.
"Traffic is a coiled serpent. A pest or plague has fallen on
Los Angeles -
it is called rain."
It seems that after a 10-month drought, the longest since 1877,
and the
correspondent reporter goes on as pitilessly as Job -
"Poisonous filth is
bleeding into the ocean - oil, gasoline, antifreeze, brake pads,
plastic
bags, industrial waste, lawn fertiliser, animal dung.
"People," he ends, "are nervous about the rain.
Very many stayed home."
In the city of the angels no angel was heard from but the burden
of the
story is the old one in Revelation: Babylon - I mean Los Angeles
- is
fallen, is fallen, that great city.
Well on the heels or in the wake of this mock melodramatic piece
came news
from the south which did not lend itself to humour.
In a normal week through the spring and summer the south, the
Deep South -
Louisiana, Mississippi, Alabama, Georgia - tornadoes whirl
through two or
three small towns and destroy them.
This is so common as barely to make the end piece of the evening
news.
But two weeks ago the dreaded black cone on the horizon appeared
between the
Gulf of Mexico and northern Pennsylvania - a 1200-mile path.
Seventy tornadoes whirled through and turned 70 small communities
into trash
heaps.
This unprecedented reach of disaster added another deep sigh to
our daily
anxiety.
But courage, men, the devil is dead.
On Tuesday last came wonderful great news, in a headline, an
immense
headline - one inch high, which is a massive headline for the New
York Times
- "Armageddon can wait."
The piece joyfully announced the discovery, a way of avoiding a
planetary
catastrophe that scientists now say is sooner or later bound to
happen and
that is the crashing on to our Earth of an asteroid.
Though they're always described as small, in comparison with
wonderful us,
they can run as wide, in diameter, as 490 miles.
For many years now scientists, in particular astronomers,
physicists,
engineers, have after careful calculations said that the chance
of an
asteroid colliding with our Earth is exceedingly remote.
However, the head of a scientific group at the national space
administration
says that new and more precise calculations suggest that there is
a very
good possibility of an Earth-crossing asteroid not crossing but
hitting us
with mortal consequences beyond the most satanic dreams of
al-Qaeda.
"Time," says the NASA spokesman, "to begin work on
a new method of dealing
with this prospect."
Until now the agreed technique for destroying an asteroid headed
our way has
been a nuclear weapon, destroying it on its Earthbound path.
But now they've decided that such a weapon would smash the
asteroid into
smaller pieces and spread its lethal damage.
So what the NASA group and other scientists are working on are
ways of
deflecting the asteroid out of its threatening orbit.
There are several new techniques of doing this. But you're saved
from
hearing about them because they're not only too complicated to
explain,
they're too complicated for me to understand.
The simplest and at the moment the most beguiling new principle
is to change
the heat radiating from the asteroid which would change its orbit
and force
it to miss us.
And this can be done either by painting the asteroid black - I'll
leave it
to you to figure out how many teams of astronauts could do this
across a
200-mile rock - or reducing the heat absorbed from the sun by the
Yarkowski
effect.
And if you don't know that Yarkowski invented this effect a
century ago - a
development of Newton's opposite motion theory - then frankly we
have no
business discussing this in front of the children.
All right so how soon is there a likelihood of a crashing
asteroid?
The question reminds me of the American scientist who first
discovered that
our human eyes were beginning to grow closer together, which
provoked the
response from the late Robert Benchley: "My eyes are so
close together as it
is, I bet I make it - I bet I'm the first one-eyed man in the
world."
Happily the answer from NASA is the same as the answer from the
eye
specialist.
"Soon", they say, could mean possibly this century,
more likely through the
next millennium or even beyond.
So the good word is don't panic but don't get too cocky either.
Back to Earth and more pressing problems.
Last Tuesday the Senate of the United States witnessed certainly
an historic
event: the creation of a government department bigger than any
other except
defence 50 years ago.
It's the new Department of Homeland Security and it was voted
into being by
the Senate, by a vote of 90 to 9.
It is, need I say, a massive response to the events of 11
September.
It will have 170,000 employees. It's a huge amalgam of 22
departments that
had, until now, a separate existence.
It includes the entire Customs Service, the Immigration And
Naturalisation
Service, the Federal Emergency Service - which goes to work after
natural
disasters - the Border Patrol, the Coastguard, six or seven
specialist
science departments and - of all proud and until now independent
groups -
the Secret Service, founded during the Civil War to detect and
prosecute
counterfeiting but since the assassination of Lincoln has been
solely
responsible for the protection of the person of the president and
his family
and by extension, since the dreadful 11th, other members of the
cabinet.
There was fierce and inconclusive congressional debate for weeks
about the
feasibility of this new corporation or incorporation but what
swiftly
concluded all useful debate and dealt the death blow to this lame
duck
Congress was simply the totally unexpected landslide of the
president's
party in the congressional elections.
Any possible nucleus of opposition shrank and collapsed. And this
may turn
out to be true of much domestic legislation in the new Congress
which starts
work in January, in the sense that most domestic issues cringe
and shrink
before the looming presence of another terrorist strike.
So the business of government is now enormously devoted to the
physical
safety of 280 million people, on the land, the sea, the ports,
the air, the
lakes, the dams, the centres of business, of diplomacy, of
sports, any
building or institution of the United States at home or abroad
whose
paralysis or poisoning could badly hurt the American economy.
The Twin Towers and the Pentagon were monstrous and from
al-Qaeda's point of
view very effective wounding strikes.
And how does this produce the impotence of the Democrats? Because
if they
were in power they'd have to have the same preoccupation, they'd
be doing
the same things.
The other day the government reported the new system of
protecting every
reservoir in the United States - which may well be an impossible
task - with
24-hour patrols by men on foot, by helicopters and small special
planes
equipped with radar and sonar.
And what would the Democratic policy be? To use radar but not
sonar?
There is, in the present preoccupation of the government, hardly
any place
for party politics. Al-Qaeda has, for the time being anyway, put
it on hold.
In the general anxiety it's hard to get worked up about free
prescription
drugs for grandma, lower interest rates on mortgages and most of
all for
keeping untouched the personal freedom to come and go - the civil
liberties
that always have to go in wartime.
And if you want to know what that general anxiety is - it is
waiting for the
other shoe to drop.
Copyright 2002, BBC
============
(4) SCIENTISTS HURL ROCKS TO STUDY SPACE BACTERIA
>From The Daily Camera, 25 November, 2002
http://www2.dailycamera.com/bdc/science/article/0,1713,BDC_2432_1569238,00.html
By SUE VORENBERG
New Mexico Tech wants to see what happens when bacteria fly.
Scientists at the university are testing bacteria-filled rocks to
see if the
organisms can survive the extreme pressures and temperatures
involved in a
meteor impact on another planet that might send them to Earth. If
the
bacteria prove hardy, it might mean that life could be widespread
across the
universe.
"People kind of thought of this as crazy science fiction in
the past, until
we found this meteorite from Mars and discovered evidence of life
in it in
the 1990s," said Eileen Ryan, a research scientist at Tech's
Magdalena Ridge
Observatory Project. "Studying these rocks has implications
for how we view
ourselves and our place in the universe. It's an exciting idea
that we're
not alone."
Meteor impacts, which can create large explosions, often send
rocks from a
planet's surface hurtling through the atmosphere into space. If
there were
bacteria or other micro-organisms in those rocks, they would be
carried
along for the ride, Ryan said.
If the tiny critters can easily withstand the trip - which is
what Ryan's
research shows so far - then it's possible that bacteria have
hitched rides
on rocks to planets all over the galaxy. And if that's true,
there's a good
chance they have evolved into myriad other life forms on some of
those
planets, Ryan said.
"It would be much cooler if we found little green men
instead of bacteria in
these rocks, but the presence of bacteria has far-reaching
implications,"
Ryan said.
Scientists have already learned through experiments that bacteria
can
survive quite well in a frozen vacuum, which bodes well for
Ryan's theory.
Until recently nobody had tested how well they could survive the
initial
impact conditions that would have sent them into space.
To test that, Ryan and students from Tech, New Mexico State
University and
Highlands University have been blasting bacteria-filled sandstone
rocks from
Arizona - which are similar to rocks that might be on Mars - with
a really
big gun.
"What we hope to do is look at impacts and try our best to
replicate the
environment, including the stress, pressure and temperatures of a
collisional event," Ryan said.
To see just how hardy the tiny critters are, Ryan and her
students tested
how much bacteria was inside the rock before the experiment. Then
they
placed the rock in a 9-foot-by-5-foot chamber that looks a bit
like a small
submarine and fired a hunk of metal at it.
The projectile was shot from a 6-foot-long gun at about 60 miles
a second.
At that speed, one could travel from Albuquerque to Santa Fe in
less than a
minute.
"Even using the gun is pretty dangerous - we all have to
clear the area and
go to a concrete bunker when it's fired," she said.
"When the projectile
hits the rock it creates dramatic pressure and temperature
inside, similar
to that of an impact."
After the rock explodes, Ryan and her students take samples of
the fragments
and test how much bacteria has survived.
"The happy end to the story is that in our tests so far they
all survived,"
Ryan said. "They're alive and doing fine."
Ryan's work is sponsored through a $1.5 million, three-year grant
from the
National Air and Space Administration's Johnson Space Center. Her
studies
will build on work done by David McKay, director of astrobiology
at the
center, who made the initial discovery in the late 1990s of
evidence of life
inside a Martian meteorite.
Ryan's work will also help scientists understand if bacteria can
hitch rides
on comets and asteroids, another hot topic in the space science
community.
Copyright 2002, The Daily Camera and the E.W. Scripps Company
============================
* LETTERS TO THE MODERATOR *
============================
(5) WHY IS EVERYONE FORGETTING THE IMPACT OF COMETS?, OR,
REALLY BIG NEWS:
COMET SHOEMAKER-LEVY 9 HITS JUPITER
>From E.P. Grondine <epgrondine@hotmail.com>
Hello Benny -
It is quite remarkable to note that in the recent coverage of the
Brown/Worden/ReVelle/Tagliafero study nearly all science writers
conveniently forgot about the impact of comets as a part of the
total impact
hazard. This is all the more remarkable when one considers that
presumably
most of those science writers were around eight years ago when
the fragments
of Comet Shoemaker Levy 9 impacted Jupiter between July 16-22,
1994, and
thus witnessed cometary impact with their own eyes.
Why did this lapse in memory occur? Was it simply that the
science writers
were lazy, and thus simply re-wrote the press release which was
handed to
them? I don't think so...
This failure to take into account the cometary impact hazard,
even though it
has been personally observed, is also reflected in both Ed Weiler
and David
Morrison's testimony before the Congress, as well as the
Representatives
re-action to it. The cometary impact impact hazard was not
mentioned for over 2 hours, until Brian Marsden insisted on
bringing it to
the Subcommittee's attention before the hearing closed. The
Representatives
literally stopped in their tracks at Marden's comment; since the
Representatives had earlier requested NASA to report on both
asteroids and
comets, apparently their own memories of Comet Shoemaker Levy
hitting
Jupiter had failed them as well...
It is also interesting to note in this regard that some of the
assumptions
made about comet impact hazard and reported as fact are simply
nonsense. For
example, it is often reported that an asteroid impact killed the
dinosaurs, when the Pacific
seabed sample is now known to be a carbonaceous chondrite likely
of cometary origin. Also
peculiarly, while there have been many pieces written about a
"Nemesis"
gravitational body which no one can find, Clube and Napier's
hypothesis on
the 26 million year periodicity of extinctions and the tie to
comet influx
is simply generally unknown and unreport. Simultaneously, the
role of comet
impact in the bulk of recent small impact events ( for a summary
of these
see
http://abob.libs.uga.edu/bobk/ccc/ce091702.html)
is also generally unknown.
Perhaps these two facts are related, and have some common cause.
Fallacies abound. It is asserted without any supporting evidence
that any
long period comet will be massive enough to be detected quite
early, while
by actually looking at the historic impact record such as it is
(above) it
appears that comets may come in all sizes. It is also sometimes
asserted,
again without evidence, that impacting comets would be impossible
to
distinguish from the Oort Cloud, when in point of fact those on
Earth
approach could be detected by a system such as Dr. Mazanek's
COMET and
Asteroid Protection System (CAPS).
Since Earth impacting comets can both be detected and stopped
from
impacting, if appropriate funds are spent, why is there this
widespread
inability to remember, this failure of
memory on so massive a scale? Is it simply the scale of the
event? Is
Jupiter too remote? I open the floor for discussion.
For Conference participants, while the new study will be of great
use in
getting a better grasp on the asteroid impact threat, it is well
known to
all here that the flux of comets is not constant over time. It
will be
interesting to see how the authors of the study factored out the
impacts of
carbonaceous chondrites (presumably dead comets) from the impacts
of comets
from the outer solar system.
Best wishes,
Ed
=================
(6) AND FINALLY: "ASTEROID DANGER DISCOUNTED"
>From The Washington Post, 25 November 2002
http://www.washingtonpost.com/wp-dyn/articles/A28459-2002Nov22.html
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