PLEASE NOTE:
*
CCNet 5/2002 - 8 January 2002
-----------------------------
"David Jewitt, an astronomer at the University of Hawaii at
Honolulu, has estimated there is a one-percent statistical chance
that the
Earth will be struck by a 300 m asteroid sometime this century.
"Such
an impact would deliver a withering 1,000 megatonne explosion and
cause
perhaps 100,000 deaths," according to his assessment, adding
that in a
densely- populated area, such as the US eastern seaboard or
western
Europe, the fatalities could rise into "tens of
millions."
--Agence France-Presse, 7 January 2002
"Dr Roderick Willstrop, of the Institute of Astronomy at
Cambridge
University, said: "Our knowledge of these smaller NEOs is
rather sketchy.
We don't have a system in place to spot them all. The only way to
deal with it is to give yourself enough time and launch rockets
to
stage an explosion in space which will deflect the asteroid
sufficiently off
course to avoid us."
--The Independent, 8 January 2002
(1) HOW COSMIC RADIATION CAN AFFECT COURSE OF BIOLOGICAL
EVOLUTION
Andrew Yee <ayee@nova.astro.utoronto.ca>
(2) STRANGE OBJECT FOUND, DEFYING IDEAS OF SOLAR SYSTEM FORMATION
Space.com, 7 January 2002
(3) ASTEROID GIVES THE EARTH A CLOSE SHAVE
The Times of India, 7 January 2002
(4) EARTH ESCAPES BRUSH WITH KILLER ASTEROID
CNN, 7 January 2002
(5) CLOSE ENCOUNTER PROMPTS CALL FOR ASTEROID WATCH PLEA FOR NEW
VIGIL SYSTEM
The Independent, 8 January 2002
(6) BEINAHE-KOLLISION: ASTEROID VERFEHLTE ERDE KNAPP
Spiegel Online, 7 January 2002
(7) IMPACT STRUCTURES OF BOLIVIA, CHILE AND URUGUAY: REVIEW AND
BIBLIOGRAPHY
Maximiliano Rocca <maxrocca@hotmail.com>
(8) WATCH A COMET SWING BY THE SUN
Space Weather News for January 7, 2001
(9) NASA WON'T CUT FUNDING FOR RADAR TELESCOPE
Florida Today, 6 January 2002
(10) CERES: A TEXAS-SIZED SPACE ROCK
Ron Baalke <baalke@jpl.nasa.gov>
(11) NEO INFORMATION CENTRE & UK NEO OBSERVATIONS
Alan Fitzsimmons <A.Fitzsimmons@Queens-Belfast.AC.UK>
(12) QUANDRANTID PARENT
Marco Langbroek <m.langbroek@rulpre.leidenuniv.nl>
(13) QUANDRANTID PARENT: A RESPONSE
Duncan Steel <D.I.Steel@salford.ac.uk>
(14) ASTEROID 2001 YB5
Larry Robinson <lrobinsn@ix.netcom.com>
(15) TSUNAMI DANGER FROM A 300m ASTEROID
Michael Paine <mpaine@tpgi.com.au>
(16) HAPPY BIRTHDAY PROFESSOR HAWKING!
Andy Nimmo <andy-nimmo@ntlworld.com>
(17) BIODIVERSITY OR BIOMASS?
Hermann Burchard <burchar@mail.math.okstate.edu>
(18) STONEHENGE: AN EARLY IMPACT WARNING DEVICE?
Pavel Chichikov <fishhook@erols.com>
==============
(1) HOW COSMIC RADIATION CAN AFFECT COURSE OF BIOLOGICAL
EVOLUTION
>From Andrew Yee <ayee@nova.astro.utoronto.ca>
Office of Public Affairs
University of Texas at Austin
P O Box Z
Austin, Texas 78713-7509
(512) 471-3151 FAX (512) 471-5812
Contact:
Rebecca Johnson, (512) 475-6763, rjohnson@astro.as.utexas.edu
January 7, 2002
Radiation zaps Mars and extrasolar planets, affects biological
evolution
AUSTIN, Texas -- Calculations by a team of astronomers at The
University of
Texas at Austin show that jolts of radiation from space may
affect
biological and atmospheric evolution on planets in our own solar
system and
those orbiting other stars. The work by David Smith (a former
UT-Austin
undergraduate, now a graduate student at Harvard University) and
UT-Austin
astronomers John Scalo and J. Craig Wheeler is presented today at
the
American Astronomical Society meeting in Washington, D.C.
Bursts of radiation that can cause biological mutations, or even
deliver
lethal doses, can come from flares given off by the planet's
parent star or
from more remote cosmic events (e.g., supernovae and gamma-ray
bursts). The
magnitude of the effect on life and evolution on a planet is
related to how
much protection it gets from its atmosphere. The work presented
today
concentrates on the transmission of high-energy X-rays and
gamma-rays
through planetary atmospheres.
"It's a multi-level calculation," Scalo said.
"First you have to determine
the spectrum of the source [flare star, supernova, or gamma-ray
burst], then
you must calculate how the radiation propagates through and
disrupts a
planet's atmosphere. Then you follow the radiation down to
the surface of the planet, even underwater, eventually
calculating how
strongly it interacts with cellular material. The calculation
presented
today follows the paths of individual photons as they scatter off
electrons
bound in molecules and gradually lose energy until they are
absorbed by
atoms. The result shows just what fraction of the radiation
reaches a
planet's surface (as function of the intensity and energy of the
source and
the thickness of the planetary atmosphere)."
Today, Mars has a thin atmosphere -- about 100 times thinner than
Earth's.
More than 10 percent of the incident energy reaches its surface
for photons
with energies above about 100 kiloelectron volts (high energy
X-rays and
gamma-rays). "Any organisms unprotected by sufficient solid
or liquid
shields should have been lethally irradiated by cosmic radiation
sources
many times in the last few billion years," David Smith said.
According to John Scalo, "It may have been safe on Mars
during the first few
billion years, when the planet had a much thicker atmosphere, but
today, and
probably for the past billion years or so according to current
climate
evolution models, the planet has had little protection
from high-energy radiation. When the atmosphere thinned, any life
on the
surface was exposed to high-energy radiation from exceptionally
strong solar
flares and occasional stronger bursts from different astronomical
sources
throughout the Galaxy."
The radiation need not be lethal, but may instead induce episodes
of intense
mutational damage and error-prone repair, leading to
interestingly different
evolution than on Earth. Mutations are usually deleterious, but
they provide
the diversity necessary to drive evolution. "Radiation
bursts may spur
evolution by intermittently enlarging the genomic diversity upon
which
natural selection is believed to operate," Scalo said.
"As an example,
chemical pathways adapted to a rapidly fluctuating radiation
environment
might result in organisms whose signatures of biological activity
may be
very different from those of terrestrial organisms.
"Gamma-ray bursts only last 10 seconds or so," Scalo
said, "so the mutations
they cause are unlikely to produce direct evolutionary
effects." Exposure to
gamma-ray bursts will tend to sterilize life on the exposed side
of the
planet that is not protected under enough rock
or water; however gamma-ray bursts may cause long-lived changes
indirectly
by affecting planetary atmospheres. Significant gamma-ray
irradiation from
supernova explosions are more frequent and have a much longer
duration and
may be capable of driving evolutionary effects directly. Both of
these
distant cosmic sources are capable of delivering atmospherically
and
biologically significant high-energy radiation jolts every
hundred thousand
or million years -- possibly hundreds or thousands of such events
over the
history of a planet.
This picture of sporadic zaps of radiation is quite different
than when a
planet is constantly bathed in radiation from its parent star.
"Most stars
in our galaxy aren't like the Sun," Scalo said. "Most
are red dwarfs." These
stars have little ultraviolet radiation that can cause mutations,
but they
flare violently, mostly in X-rays. "Conventional wisdom said
that planets
orbiting these stars couldn't have atmospheres, that any
atmosphere would freeze out
because the planet's rotation would be tidally locked,"
Scalo said. "More recent
calculations show these planets can have atmospheres. What might
life be
like on a planet orbiting a red dwarf with powerful flares and
continuous
intense coronal X-rays? One possibility is that most of the
biosphere would
need to be underground or underwater; another is that the
challenging
mutational radiation environment would accelerate the evolution
of life."
Future work will focus on the reprocessing of the lost gamma-ray
and X-ray
energy to ultraviolet radiation that can reach the ground. The
high-energy
photons lose energy to electrons that in turn excite atoms and
molecules in
the atmosphere. When those atoms de-excite, they can produce
substantial
ultraviolet radiation that can also affect the biosphere on the
surface of
the planet. In this case, bursts of cosmic irradiation would be
important
even when there is a thick atmosphere (like Earth's) that will
stop the
original X-rays or gamma-rays. These jolts of irradiation can
cause the
formation of a "second ionosphere" at fairly low
altitudes and disrupt a
planet's atmospheric chemistry. Smith, Scalo, and Wheeler are
adding these
effects into their calculations.
IMAGE CAPTION:
[ http://stardate.utexas.edu/pr/pressroom_images/20020107/Scalo_Release_Figure.jpg
(164KB)]
Mars: Atmospheric transmission of high energy photons as a
function of time.
=============
(2) STRANGE OBJECT FOUND, DEFYING IDEAS OF SOLAR SYSTEM FORMATION
>From Space.com, 7 January 2002
http://www.space.com/scienceastronomy/gemini_keck_020107.html
By Robert Roy Britt
Senior Science Writer
WASHINGTON D.C. - Solar system creation theorists got more to
chew on Monday
when astronomers announced the discovery a huge object called a
brown dwarf
orbiting a star nearly as closely as Saturn is to our Sun.
Added to recent findings of extrasolar planetary systems that are
markedly
unlike the one around the Sun, the new finding makes our solar
system look
like an oddball in the galaxy.
Brown dwarfs are large balls of gas, much more massive than
Jupiter but not
heavy enough to generate the thermonuclear fusion that powers a
star. In
recent years, these strange, in-between objects have been found
in so many
bizarre configurations that researchers are scrambling to figure
out whether
they are dealing with one class of object or several.
Lone brown dwarfs have been spotted wandering through space
fairly nearby.
Others have been detected at vast distances from other stars,
forming in
nests. Brown dwarfs might even spawn their own planetary systems.
And scientists have struggled and argued over the specific
differences
between brown dwarfs and planets, especially how and where they
are born.
Finding a brown dwarf in a region around a star thought to be
reserved for
planets will only exacerbate ongoing disagreements.
"This finding suggests that a diversity of processes act to
populate the
outer regions of other solar systems," said Michael Liu, a
University of
Hawaii astronomer who led the team that made the discovery.
Liu and his colleagues, a group of venerable planet hunters,
found the
object using the Gemini North and Keck telescopes at Mauna Kea,
Hawaii. The
results were presented here at a meeting of the American
Astronomical
Society.
So close
The brown dwarf is just 14 Astronomical Units away from the star
(1 AU is
the distance from Earth to the Sun). Saturn is 10 AU from the
Sun, and
Uranus, the next planet out, is 19 AU. The object is between 55
and 78 times
as massive as Jupiter, which is the largest planet in our solar
system.
Researchers say the configuration of a star and such a large,
close
companion can't be explained by current theories of solar system
formation.
Stars are created by the gravitational collapse of a cloud of
material.
Planets, however, are thought to develop out of a flat, rotating
disk of
material left over from the creation of a star. Planet evolve
when smaller
rocks, like comets and asteroids, get together. Jupiter and the
other gas
giant planets probably have origins in such rocky cores, which
grew large
enough to attract a huge gas envelope, most astronomers believe.
"This [brown dwarf] companion is probably too massive to
have formed the way
we believe that planets do," Liu said.
Many stars also are known to form as pairs, orbiting each other.
So
researchers will want to learn whether the newly spotted brown
dwarf formed
at the same time as its host star, or perhaps was a drifter that
got drawn
in by the star's gravity.
Hunting planets
Hints of the brown dwarf were initially spotted a decade ago by a
team of
extrasolar planet hunters.
Geoff Marcy and Debra Fischer at the University of California at
Berkeley,
along with Paul Butler of the Carnegie Institution, have helped
find many of
the 80 or so known extrasolar planets. Their technique, which
notes slight
wobbles in a star caused by large, closely-orbiting planets,
could not
definitively identify what they suspected was a brown dwarf
farther out from
a star called HR 7672, which is 58 light-years away from Earth.
Current techniques cannot find small planets, either. The
extrasolar planets
that have been identified in the past 5 years are all very large.
Most are
bigger than Jupiter and orbit very close to their host stars.
Some are as
close as Mercury is to our Sun.
Already, astronomers were struggling to explain how planets so
large could
exist so close to stars. And they wonder whether this is normal,
or whether
other solar systems like ours might be the norm but simply have
eluded
detection so far.
The answer bears on whether there are other Earth-like planets
out there,
which might support life.
Answers won't come, however, until technology allows for the
discovery of
small extrasolar planets, assuming they exist. One space-based
observatory
that would do this, called Kepler, was approved by NASA in late
December and
is scheduled to launch in 2006. Kepler would succeed by doing its
observing
from above the blurring effects of Earth's atmosphere.
Other researchers are working to stretch ground-based observation
techniques
beyond current limits to allow for the discovery of smaller
planets and of
large objects orbiting far from stars. The new discovery
represents one of
these efforts.
How it was found
Brown dwarfs generate enough heat to shine, but only dimly and in
infrared
light.
The newly spotted brown dwarf was found using a relatively new
technique
called adaptive optics, which corrects for some of the blurring
effects of
Earth's atmosphere and allows faint objects to be photographed
with greater
resolution.
Liu imaged the primary star HR 7672 (also called 15 Sge) last
summer, and he
noticed a dim spot of light next to it, described as being akin
to a firefly
next to a bright searchlight. Follow-up images, using adaptive
optics,
showed the faint object moved on the sky along with the primary
star,
proving that it was in fact a companion and not a background
star.
HR 7672 is slightly younger than our Sun, but otherwise very
similar. The
researchers are now looking for similar groupings of other stars
and brown
dwarfs.
"Now that we know brown dwarfs exist in the region of giant
planet
formation, we would like to understand how often these oddball
pairings
occur in the universe, and what that can tell us about the
alternate and
divergent ways in which solar systems form around Sun-like
stars," Liu said.
James Graham and James Lloyd, also from the University of
California at
Berkeley, contributed to the study.
Copyright 2002, Space.com
==============
(3) ASTEROID GIVES THE EARTH A CLOSE SHAVE
>From The Times of India, 7 January 2002
http://timesofindia.indiatimes.com/articleshow.asp?art_id=438188095
AFP, PARIS: An asteroid big enough to wipe out a major country
gave the
Earth a close shave on Monday, passing less than twice the
distance of the
moon from our planet, astronomers reported.
The space rock, designated 2001 YB5, measures between 220 and 490
m and at
its closest point, at 0737 GMT, hurtled past about 600,000 km
from the
Earth, according to varying estimates on US and European
specialist
websites.
2001 YB5 was spotted in early December by a Near-Earth Asteroid
Tracking
(NEAT) survey telescope on Mount Palomar in California, NASA said
on its
Near-Earth Object (NEO) Programme website.
Although there had been no danger of collision from the asteroid,
experts
said the distance was a whisker in cosmic terms.
"Such an object could literally wipe out a medium-sized
country if it
impacted and lead to a global economic meltdown, unless we were
extremely
fortunate and it hit somewhere remote," Benny Peiser, an
asteroid expert at
Liverpool John Moores University, said over phone.
Only one other identified asteroid, a rock called 1999 AN10, will
come
closer, making a flyby on August 7 2027 at about 389,000 km,
about the
distance from the Earth to the moon.
An object 220-490 m across would release energy equivalent to
hundreds of
atomic bombs if it wacked into the Earth.
A large object, believed to be up to 10 km long, smashed into
Mexico's
Yucatan peninsula 65 million years ago.
Scientists believe the object, either a comet or an asteroid,
triggered a
firestorm and then a dust cloud that obscured sunlight. It
inflicted lasting
climate change that destroyed vegetation and ended the long reign
of the
dinosaurs.
In 1908, an asteroid or comet about 60 m long exploded over
Siberia with the
force of 600 times the Hiroshima bomb, reducing a 40 km wide
patch of forest
to matchwood.
2001 YB5 has been categorised by NEAT as a "potentially
hazardous" asteroid.
Although it poses no danger at all to the Earth at the moment,
that could
theoretically change in the future if its orbit around the Sun is
deflected
by the gravitational pull of a nearby planet.
Its trajectory crosses the orbits of Mars, Earth, Venus, and
Mercury, NEAT
said.
Astronomers are becoming increasingly vocal about the risks of
asteroid
collision, saying Earth has simply had a long run of good luck in
escaping
big cosmic debris for so long.
NASA's main focus is on identifying asteroids between one km and
10 km
across.
The number of these bruisers was once put at 1,000-2,000, which
translates
into a roughly one-per cent chance that one of them will smash
into the
Earth in the next thousand years. In January 2001, that estimate
was
downgraded to 700, plus or minus 230.
Even so, that leaves the vast majority of space objects, which
are under one
km, still to be detected.
Noting the belated discovery of 2001 YB5, Peiser said, "had
we discovered
that the thing were on a collision course, there is nothing that
we could
have done... nothing has been done on planetary defence."
David Jewitt, an astronomer at the University of Hawaii at
Honolulu, has
estimated there is a one-percent statistical chance that the
Earth will be
struck by a 300 m asteroid sometime this century.
"Such an impact would deliver a withering 1,000 megatonne
explosion and
cause perhaps 100,000 deaths," according to his assessment,
adding that in a
densely-populated area, such as the US eastern seaboard or
western Europe,
the fatalities could rise into "tens of millions."
On January 1, the British government announced it was setting up
a centre in
Leicester, central England, to pool information about potentially
hazardous
asteroids.
It will also launch a pilot study to track asteroids using a
telescope on
the Canary Islands, in the central-eastern Atlantic.
All rights reserved. © 2000 Agence France-Presse.
==========
(4) EARTH ESCAPES BRUSH WITH KILLER ASTEROID
>From CNN, 7 January 2002
http://europe.cnn.com/2002/TECH/space/01/07/killer.asteroid/index.html
By Richard Stenger
CNN Sci-Tech
(CNN) -- An asteroid that could pulverize a country zipped close
by the
Earth on Monday, only weeks after astronomers first noticed the
big space
boulder heading in our direction.
The Near Earth Object brightened enough for even simple
telescopes to spot
just before it raced past our planet on Monday, only two times
the distance
of the moon, according to spaceweather.com, a NASA-affiliated Web
site.
The range might seem like enough to breath easy, about 600,000 km
(375,000
miles), but many scientists classify it as a relatively close
call.
The asteroid, officially known as 2001 YB5, measures between 300
and 400
meters (1,000 to 1,300 feet) in width. If such a rock were to
smash into the
planet, it would unleash the same amount of energy as many
nuclear bombs,
astronomers estimate.
"The impact would be quite tremendous. It could essentially
wipe out a
medium-sized country," said Benny Peiser of the Royal
Astronomical Society
in Great Britain. "The environmental consequences would be
regional but the
social and economic consequences would be global."
Close encounters with giant space rocks are not uncommon.
Asteroids
comparable to 2001 YB5 could strike the Earth as frequently as
once every
5,000 years, Peiser said.
The space rock 2001 YB5, identified by the arrow, could have
wiped out
France, according to a scientist in Britain.
In much rarer instances, boulders one kilometer or greater in
size have
smacked into the planet and snuffed out most life forms, much
like the
six-mile (10-km) long monster thought to have forced dinosaurs to
exit stage
left about 65 million years ago, according to scientists.
In the year 2027, an asteroid between one kilometer and mile in
length is
expected pass even closer than 2001 YB5. Having pinpointed its
orbital path,
scientists dismissed any potential of danger.
But later on, either asteroid could pose risks to the planet,
along with
countless rocks lurking in the shadows that have yet to be
identified,
astronomers warn.
What particularly troubles Peiser is that scientists only first
spotted 2001
YB5 in early December. What if it had been heading on a collision
course?
"That's not enough time for any initiatives for deflection.
If we had 20 or
30 years' time, then we could develop a technology to deflect an
object.
With our current lacked of preparedness, we are helpless,"
he said.
Copyright 2002, CNN
===========
(5) CLOSE ENCOUNTER PROMPTS CALL FOR ASTEROID WATCH PLEA FOR NEW
VIGIL
SYSTEM
>From The Independent, 8 January 2002
http://news.independent.co.uk/uk/science/story.jsp?story=113341
By Cahal Milmo
In intergalactic terms, it was a close shave. An asteroid capable
of causing
widespread devastation narrowly missed the Earth yesterday.
Although the nearest the asteroid came to Earth was 390,000
miles, had it
arrived four hours earlier on its journey around the Sun it would
have
scored a direct hit.
The asteroid - measuring 300 metres across and known as 2001 YB5
- passed
Earth at 7.37am. For a moment, it was less than twice as far from
the Earth
as is the Moon.
Scientists were unaware of its approach until a month ago, when
it was
spotted by an American observatory dedicated to tracking near
Earth objects
(NEOs).
Astronomers insisted there was never any danger of a collision
with Earth.
But they warned that the asteroid was one of up to 400,000 small
NEOs up to
1,000 metres wide that could strike Earth with little or no
warning because
of the absence of an adequate early- warning system.
The idea of a catastrophic asteroid strike has long been a source
of morbid
fascination, most recently manifesting itself in Hollywood
disaster movies
such as Armageddon and Deep Impact. The potential consequences
are indeed
apocalyptic, according to research on asteroid impacts. If a
300-metre
asteroid hit London, it would destroy everything within a 95-mile
radius and
cause severe damage for a further 500 miles - wiping out the UK,
the Low
Countries and much of France.
In the more likely event of a similarly sized NEO landing in the
sea (70 per
cent of the Earth's surface is covered by water), it would
trigger a series
of tsunamis - massive waves - that would devastate coastal
regions.
Jonathan Tate, director of Spaceguard UK, which campaigns for a
British-funded telescope to watch for such asteroids as part of a
global
network, said: "YB5 is one of hundreds of thousands of
objects which present
an unknown risk to the planet.
"What limited resources exist for tracking asteroids are
dedicated to
spotting the 700 to 1,200 which are more than a kilometre in
diameter and,
if they hit the Earth, could wipe out the planet.
"That leaves very few resources for trying to trace the many
more asteroids
between 100 metres and 1,000 metres in diameter which still
present a very
significant risk.
"This particular asteroid passed us by without any danger
but it remains
that by the time it was spotted last month, there was nothing we
could have
done to avert a catastrophe had it been heading toward us."
YB5 was identified four weeks ago by scientists at the Near Earth
Asteroid
Tracking observatory on Mount Palomar, California, part of
America's system
for picking up large asteroids.
There are estimated to be about three or four "close
encounters" with NEOs
every month. The only known object that will pass nearer to Earth
than YB5
is another asteroid, 1999 AN10, on 7 August 2027.
Astronomers say greater resources are required to provide
long-range
forecasting. Spaceguard UK estimates that the cost of British
participation
in a global early warning network would be £35m.
Dr Roderick Willstrop, of the Institute of Astronomy at Cambridge
University, said: "Our knowledge of these smaller NEOs is
rather sketchy. We
don't have a system in place to spot them all."
Were a dangerous NEO to be spotted, however, fans of the
Hollywood version
of asteroid defence will be glad to know that the solution is
straight out
of the realms of fiction.
Dr Willstrop said: "The only way to deal with it is to give
yourself enough
time and launch rockets to stage an explosion in space which will
deflect
the asteroid sufficiently off course to avoid us."
Copyright 2002, The Independent
===========
(6) BEINAHE-KOLLISION: ASTEROID VERFEHLTE ERDE KNAPP
>From Der Spiegel Online, 7 January 2002
http://www.spiegel.de/wissenschaft/0,1518,175808,00.html
In kurzer Entfernung hat ein Asteroid vor wenigen Stunden die
Erde passiert.
Die Begegnung mit dem Felsbrocken, der bei einem Volltreffer ein
ganzes Land
hätte auslöschen können, betrachten Astronomen als Warnung.
In astronomischen Begriffen verlief das Rendezvous, das die Erde
am Montag
ohne Schaden überstand, äußerst eng: Ein Asteroid von etwa 300
Metern Größe
passierte den Planeten um 8.37 Uhr MEZ in einer Entfernung, die
etwa dem
doppelten Abstand zwischen Erde und Mond entspricht. Zwar bestand
für die
Menschheit keine Gefahr, Astronomen nutzen jedoch die
Gelegenheit, um vor
der Gefahr aus dem Weltraum zu warnen.
Besorgnis erregend ist vor allem, dass der Himmelkörper, dessen
stark
elliptische Bahn die von Mars, Erde, Venus und Merkur schneidet,
erst im
Dezember entdeckt wurde. Das Objekt mit dem Namen 2001 YB5, das
die Sonne
einmal in 1321 Tagen umkreist, war Anfang des Monats
Asteroidenjägern des
Suchprogramms Neat (Near Earth Asteroid Tracking) aufgefallen.
Dass der Fund erst kurz vor der Annäherung an die Erde gelang,
gibt
Astronomen zu denken. Die späte Entdeckung führe zu der Frage,
"ob wir
genügend Zeit zum Handeln gehabt hätten, wenn sich das Objekt
auf einem
Kollisionskurs befunden hätte", sagte Benny Peiser von der
Liverpool John
Moores University gegenüber "BBC News Online". Die
Antwort steht für den
Forscher bereits fest: "Natürlich nicht, wir hätten nichts
daran ändern
können."
Bei einem Einschlag hätte 2001 YB5 wohl nicht die gesamte
Menschheit
ausgelöscht - um solch eine Energie freizusetzen, müsste das
Einschlagsobjekt etwa einen Kilometer Durchmesser besitzen.
Allerdings würde
auch schon ein 300-Meter-Felsbrocken fürchterliche Verwüstungen
anrichten:
Wie Astronomen vermuten, könnte ein solches Geschoss ein
gesamtes Land
vernichten, wobei es noch in über 800 Kilometer Entfernung
schwere Schäden
hervorrufen würde.
Gebannt ist die Gefahr eines solchen Aufpralls nicht: 2001 YB5
könnte, so
spekulieren die Forscher, der Erde in Zukunft noch einmal
gefährlich werden,
auch wenn das Risiko dafür relativ gering ist. Dennoch haben
ähnlich große
Himmelskörper die Erde in der Vergangenheit vermutlich schon
häufig
getroffen. Im Schnitt kommt es alle 5000 Jahre zu einer Kollision
mit einem
300-Meter-Objekt, so die grobe Schätzung der Wissenschaftler.
Auch eine lebensauslöschende Katastrophe durch ein mindestens
kilometergroßes Einschlagsobjekt ist für Astronomen nur eine
Frage der
Wahrscheinlichkeit: Nach neuesten Hochrechnungen betragen die
Chancen, dass
so ein Felsen in den nächsten hundert Jahren auf die Erde
prallen wird, eins
zu 5000.
Derartige Prognosen sind zwar kein Grund, in Panik zu verfallen.
Forscher
halten es jedoch für nötig, Vorsorgemaßnahmen zu ergreifen.
Für Peiser ist
die spät bemerkte Annäherung von 2001 YB5 deshalb ein
Warnzeichen: "Sie
erinnert uns daran, was passieren könnte, wenn wir Asteroiden
nicht genauer
überwachen und bessere Vorbereitungen treffen, um unseren
Planeten zu
schützen."
Copyright 2002, Spiegel Online
------------
Pozor na asteroid
http://www.hd-dennik.sk/index.cgi?2002.1.8+Domace+43
Asteroïde mis aarde rakelings
http://www.news24.co.za/Beeld/Wereld/0,4127,3-71_1127820,00.html
Asteroide passerte nært Jorden
http://www.ba.no/52/42/56/5.html
Un peligroso asteroide rozó la Tierra
http://www.diariohoy.net/notas/verNoticia.phtml?Nota=19853
==============
(7) IMPACT STRUCTURES OF BOLIVIA, CHILE AND URUGUAY: REVIEW AND
BIBLIOGRAPHY
>From Maximiliano Rocca <maxrocca@hotmail.com>
Dear Benny:
Bellow you will find a short article concerning a review and
bibliography
about impact structures in 3 latin american spanish speaking
nations:
Bolivia, Chile and Uruguay.
As far as I know, making the exception of Argentina, no other
spanish
speaking countries in South America have impact structures
reported. This
article remains unpublished too.
Thanks you very much!
Bye: Max
IMPACT STRUCTURES OF BOLIVIA, CHILE AND URUGUAY : REVIEW AND
BIBLIOGRAPHY.
Maximiliano Rocca -Mendoza 2779-16A,Ciudad de Buenos Aires,
Argentina
(1428DKU),maxrocca@hotmail.com
As 2001 the following impact craters/structures have been
reported in
BOLIVIA, CHILE and URUGUAY Republics, South America:
BOLIVIA:
1) Iturralde Structure, Abel Iturralde Province,( S12º35'
W67º38').
This structure ( a possible complex one ) was discovered in 1985
from
LANDSAT images and it is located in the Amazonian lowlnads of
Northwestern
Bolivia. The structure is superimposed on alluvial deposits that
accumulated
over a vast area of SW Amazonia in late Quaternary times.
LANDSAT images reveal a circular structure, about 8 kms.,with a
slightly
elevated rim, with minor radial drainage and shallow interior. An
irregular
rised area , about 2 X 3 kms., lies slightly off-center to the SE
within the
structure: a possible central uplift. Its estimated age is 30,000
to 10,000
years. So far, no "in situ" research has confirmed its
impact origin. Access
to this structure by surface is very difficult. If it is a real
impact, it
would be the youngest complex impact structure on Earth.
REF.:
-Campbell K.E. Jr., et al.: National Geographic Research 5 (4):
495-499,
1989.
CHILE:
1) Monturaqui, ( S 23º56' W68º17').
The Monturaqui simple crater was discovered in 1962 from aerial
photographs.
In 1965 research " In situ" confirmed its impact
origin: iron shale
fragments and glassy impactites were found in its rims. Shocked
minerals
enclosed in the glass confirmed its impact origen too. The
Monturaqui's
impactites also contain rock fragments and Fe-Ni spheres.
REF.:
-Sanchez J. and Cassidy W.A.: Journal of Geophysical Research 71:
4891-4895,
1966.
-Bunch T. and Cassidy W.A.: Contributions to Mineral. Petrol. 36:
95-112,
1972.
URUGUAY
1) La Paloma, Rocha Departament, ( S34º40' W54º10')
So far, no positive impact crater/structure has been found in
this area.
However, there is a report concerning possible impactites: frothy
glass
specimens were found in 1986 along the Atlantic Coast's shores of
the area.
On hand specimens, they resembled Wabar's sand fused glass
impactites. If
real impact, source crater and layers remain, so far, unknown.
The area
demands more research.
REF.: -Rocca M.C.L. : MAPS 36 (9): p.A176, 2002.
============
(8) WATCH A COMET SWING BY THE SUN
Space Weather News for January 7, 2001
http://www.spaceweather.com
Periodic comet 96P/Machholz is heating up. Every 5.24 years the
comet swings
remarkably close to the Sun, and this week is one of those times.
The comet
is growing a long bright tail as it plunges toward our star.
Unfortunately, humans can't see the comet so close to the glaring
Sun, but
coronagraphs on board the Solar and Heliospheric Observatory
(SOHO) will be
able to observe the unfolding encounter. The comet appeared
yesterday within
SOHO's field of view and will remain so for the next few days.
Unlike many Sun-approaching comets, notably the "Kreutz
sungrazers,"
96P/Machholz is expected to survive its fiery encounter.
Perihelion (closest
approach to the Sun) will take place on January 8th at a distance
of 0.12
AU.
Visit SpaceWeather.com for movies of the present encounter (and
one that
happened 5 years ago) as well as links to more information.
=============
(9) NASA WON'T CUT FUNDING FOR RADAR TELESCOPE
>From Florida Today, 6 January 2002
http://www.floridatoday.com/!NEWSROOM/localstoryA7991A.htm
Agency restores $550,000 for asteroid observations
By Kelly Young
FLORIDA TODAY
CAPE CANAVERAL -- Part of the Arecibo Observatory in Puerto Rico
got a late
save last month.
NASA said it would cut $550,000 for the large radar telescope in
Puerto Rico
that examines asteroids near Earth.
The decision drew the ire of the planetary scientists.
Supporters said it is important to study these objects because of
the
possibility of an asteroid or comet crashing into Earth and
causing a
catastrophic event like the one that likely wiped out the
dinosaurs.
Days after announcing the funding cut, NASA changed its mind and
restored
most of its contribution.
"I think that they became well aware of the quality of the
program and the
strong support of the users of the system and the planetary
community in
general," said Donald Campbell, a Cornell University
professor and leader of
the Radar Astronomy Group at Arecibo. "We were very pleased,
of course, that
NASA reconsidered its decision."
The Arecibo Observatory, used in scenes of the films
"Contact" and
"Goldeneye," is the most powerful radio observatory on
the planet and
measures 1,000 feet across. It is part of the National Astronomy
and
Ionosphere Center operated by Cornell University with the
National Science
Foundation.
Arecibo is used for more than asteroid research. For example, the
radar
portion looks at other planets. Arecibo also spotted the first
planet
outside the solar system. It measures the masses and distances of
other
galaxies, and it studies Earth's atmosphere.
Most of Arecibo's funding comes from the National Science
Foundation, which
provides $9.5 million annually for operating costs.
Until this year, NASA's Near Earth Object program contributed
$550,000 of
its $3.55 million annual budget for the observatory's radar
astronomy
program. Among other things, this money paid for the study of
asteroids and
comets larger than one kilometer whose orbits take them close to
our planet.
As part of the reprieve, NASA will pitch in $400,000 through the
end of
fiscal year 2002.
But in 2003, scientists who want to use Arecibo will have to
compete for
NASA money like other groups in the Near Earth Object program.
"There's a lot of uncertainty at this point," Campbell
said.
Arecibo does not find the asteroids; it looks at known asteroids
and
identifies their surface, size, density and orbit.
However, NASA has a congressional mandate to identify 90 percent
of the Near
Earth Objects by 2008.
"Arecibo radar observations are crucial for determining the
exact location,
speed and direction of objects that approach Earth," Louis
Friedman,
executive director of The Planetary Society, said in a statement
Dec. 20.
"We need this information to know how significant the
probability is of any
one asteroid hitting the Earth. It is irresponsible for Congress
to mandate
that NASA undertake asteroid and comet detection, and then to not
provide
sufficient funds for that program."
Finding the asteroids became the office's main objective.
"They ran into a difficulty in terms of the funding required
for their
primary objective," Campbell said. "We were a bit of a
casualty of that
difficulty."
NASA officials said they are making good progress in finding the
near-Earth
asteroids.
"I don't think there's any reason for us to think that we
can't accomplish
it," said Colleen Hartman, director of NASA's Solar System
Exploration
Division.
So far, people have identified about 570 asteroids out of an
estimated
1,000.
NASA may ask the National Science Foundation to pitch in more on
the
asteroid front.
"NSF is certainly concerned about the issue," Campbell
said. "They have not
indicated what their reaction would be to all of this."
Members of the National Science Foundation and NASA will meet
this month to
discuss the issue.
"I think the point that hasn't been really emphasized is the
amount of
observing time that NSF provides for the planetary or Near Earth
Object
program: $800,000 a year," said Richard Barvainis, NSF
program manager for
radio astronomy at Arecibo.
Barvainis said it was unclear whether NASA would ask the National
Science
Foundation to contribute more to the radar astronomy program.
NASA has been supporting Arecibo's planetary radar program since
the
mid-1970s. The space agency provided money for the first
high-powered
transmitter on the telescope for planetary work.
During the 1990s, NASA chipped in $11 million for a new
high-powered
transmitter, which has the equivalent power of 1,000 microwave
ovens.
Copyright © 2001 FLORIDA TODAY.
================
(10) CERES: A TEXAS-SIZED SPACE ROCK
>From Ron Baalke <baalke@jpl.nasa.gov>
http://www.jpl.nasa.gov/solar_system/features/ceres.html
A Texas-Sized Space Rock
Jet Propulsion Laboratory
January 7, 2002
For two centuries it was the largest known rock in the solar
system. The
Texas-sized asteroid Ceres, about 930 kilometers (580 miles)
across, was the
first asteroid ever detected. The space rock was identified in
1801 by
astronomer Giuseppe Piazzi, a monk in Sicily and the founding
director of
the Palermo Astronomical Observatory. He noted over a few nights
a shifting
point in the sky that wasn't one of the planets, their moons or a
star.
Thus, he discovered the rock.
After discovering the asteroid, Piazzi was invited to join the
Celestial
Police, a group of 24 international astronomers looking for what
they called
"guest planets" between Mars and Jupiter. The Celestial
Police noted that
the spacing between planets was fairly regular, but that there
was a large
gap between Mars and Jupiter.
Soon other small bodies were discovered in that region (Pallas in
1802, Juno
in 1804 and Vesta in 1807), so the Celestial Police concluded
that not just
one, but many minor planets had to exist in a main asteroid belt.
The
asteroid belt probably represents primitive pieces of the solar
system that
never managed to accumulate into a genuine planet.
German mathematician Karl Friedrich Gauss calculated from
Piazzi's few
observations that Ceres circled around the Sun once every 4.6
years or about
4 years, 220 days.
The asteroid has a very primitive surface, say scientists on
NASA's Dawn
mission, which will launch in 2006 and examine Ceres in 2014. The
asteroid,
like a young planet, contains water-bearing minerals, and
possibly a very
weak atmosphere and frost. Infrared observations show that the
surface is
warm.
NASA's Hubble Space Telescope observed last year that Ceres'
surface has a
large spot, which could be a crater formed when another asteroid
struck
Ceres. A second explanation may be that the spot is a darker
substance in
the asteroid's soil.
Recently, Ceres lost its claim to the title of biggest rock in
the solar
system. In July 2001, a larger object was found in the vast
Kuiper belt of
asteroids, stretching from 30 to 100 AU (2.8 to 9.3 billion miles
away from
the Sun.) This brightest and therefore biggest non-planet space
rock, 2001
KX76, could be anywhere from 960 to 1270 kilometers (600 to 790
miles)
across.
Right now, Ceres is less than three degrees away from the Sun,
making it
hard to see. In October, the asteroid will be bright enough to
see with a
little help from binoculars.
============================
* LETTERS TO THE MODERATOR *
============================
(11) NEO INFORMATION CENTRE & UK NEO OBSERVATIONS
>From Alan Fitzsimmons <A.Fitzsimmons@Queens-Belfast.AC.UK>
Dear Benny,
Happy New Year. A couple of corrections concerning the Space.com
article
from the 7th January:
>The center will not be involved in the search for asteroids,
though it might
>fund two small telescopes on the Canary Islands for doing
follow-up surveys
>on asteroids that have been discovered by other researchers.
Unfortunately, the NEOIC will not have any funds to support
research. It is
purely an information and education centre at present. Funding
for the
current small scale survey and astrometry test programmes on La
Palma is via
the normal ING Board and PPARC peer-review process.
>"There are concerns, however, that these instruments
will simply reproduce
>the search efforts of other teams in the Northern
Hemisphere," Peiser said.
If this were the case, then such efforts would indeed be
worthless. However,
astrometric and physical follow-up performed by the INT and JKT
on La Palma
could significantly aid the current international survey effort.
For
example, the JKT could perform astrometry of all visible NEOs
with V=19 or
brighter with a cycle time of 2-3 days. The INT can observe NEOs
at V=22
with 30 second exposures. I am not sure where your concerns lie.
Best Wishes,
Alan Fitzsimmons
MODERATOR'S NOTE: Dear Alan, What are my concerns? Let me first
of all
reassure you that I welcome the new UK initiatives announced
earlier this
year. Nevertheless, many observers find the slow and minimalistic
steps
taken by the Government a little disappointing. After all, the
*main*
recommendation by the NEO Task Force was that Britain should
start
contributing to the international Spaceguard effort by focusing
primarily on
the *search* for those NEOs that are currently not targeted by
others.
That's why the Task Force recommended building and setting
up a large and
dedicated *search telescope* that would specifically search
smaller NEOs.
While there is no NEO search programme in the Northern Hemisphere
that uses
an aperture as large as the Isaac Newton Telescope (INT),
Spacewatch II,
just coming on line, uses 1.8-m. Thus in terms of light
collecting power the
INT and Spacewatch II are the same. Spacewatch II, however, was
specifically
built for NEO searching, and the Spacewatch team have some 20
years of
experience behind them. The INT, on the other hand, is an antique
that was
neither designed for NEO observation nor is it really suitable
for NEO
searches. I understand that it will take a couple of years of
work to get it
working as a good NEO search tool - *if* it were available 100%.
How
realistic is this? With regards to the Johannes Kapteyn
Telescope,
recommended by the UK Task Force as a full-time dedicated
follow-up
instrument, this could observe all accessible NEOs on a few days
cycle and
provide follow-up astrometry. It's not really big enough for
physical
studies of most new-found NEOs. It certainly will not be big
enough to track
most discoveries from Spacewatch II. But it can perform well on
follow-up.
It might even match what is done at the Klet Observatory, if
there are keen
observers, as they are in the Czech Republic, on duty *all the
time*. But in
order to comply with Task Force Recommendation 4, the JKT would
need a
permanent team of a minimum of 4-6 observers with a yearly budget
of
£250,000 or so. How realistic is this? And what exactly are the
time
allocations and funds available for all this hypothetical work on
both
telescopes that are now being "tested"? Are we talking
about two new and
full-time NEO programmes or some cheap and piecemeal initiatives
that will
quickly disappoint both the hopes of those of us in Britain and
internationally? The main question that arises from all these
concerns is
simple: what proportion of the global NEO search and follow-up
effort does
the UK plan to contribute in the next couple of years? In other
words, what
is the UK productivity goal, i.e. NEO discovery rate and
astrometry
supplied, compared to that of both amateurs and professionals
around the
world? The answer to these questions will serve as the lickmus
test of the
recently announced initiatives according to which the UK and
those involved
in them will be judged. BJP
============
(12) QUANDRANTID PARENT
>From Marco Langbroek <m.langbroek@rulpre.leidenuniv.nl>
Dear Benny,
CCNet's issue of January 3 had a news item on the Quadrantid
meteor shower,
which stated that the parent comet of the Quadrantids is unknown.
In CCNet 4
of 7 January, Duncan Steel reponded to this with:
"This is not true. Periodic Comet Machholz 1 is rather
firmly established as
the parent of the Quadrantid meteor shower, along with seven
other showers
(such as the N & S Delta Aquarids)"
I disagree with Duncan Steel however, about the
"firmness" of this proposed
connection between Machholz 1 and the Quadrantids. This
connection demands
that the stream should be old, because the models which generate
the
connection base this on modelling of the cometary orbit back to
5000 years
ago, when the comet should have shed the dust that now is visible
as
Quadrantid meteors.
However, the Quadrantids definitely are a very young stream, not
an old
stream. In our 1997 Astronomy & Astrophysics paper (ref.
below), we reported
that the spread in the high accuracy multistation photographic
and video
orbits of the Quadrantids (35 photographic and 29 video orbits)
which our
Dutch Meteor Society gathered, precludes that this stream is
caused by 'old'
dust. The dispersion in orbital elements among our meteor sample
is just too
small for that. We estimated that the dust that creates the sharp
main
activity peak of this stream should not be much older than 500
years (the
wider low level background activity upon which the main peak is
superposed
could be older dust though but is too ill sampled to allow
definite
statements on that). This precludes the hypothesis that the
stream is
connected to dust shed by comet 96P/Machholz 1 as much as
5000 years ago.
This in turn rules out comet 96P/Machholz 1 as the parent for the
Quadrantids, contrary to Steel's assertion that this is
"rather firmly
established".
Given that the parent so far has not been found, it is likely
that it is
dormant. The Quadrantids are in a high inclination orbit, and so
must be
their parent, so chances that one of the current NEA programms
might
discover it are perhaps smaller than for objects with orbits
closer to the
ecliptic plane. So this is a case of a NEA (sensu lato, it being
a dormant
comet rather than an asteroid) that must be there, but apparently
masters
the skill of hiding itself well.
kind regards,
- Marco Langbroek
Dutch Meteor Society (DMS - www.dmsweb.org)
ref: Jenniskens P., Betlem H., De Lignie M., Langbroek M. and Van
Vliet M.:
Meteor stream activity V. The Quadrantids, a very young stream.
Astronomy &
Astrophysics 327 (1997), 1242-1252
Marco Langbroek
Faculty of Archaeology
Leiden University
P.O. Box 9515
NL-2300 RA Leiden
the Netherlands
building 1176, room 021
tel. +31 (0)71 5272926
fax +31 (0)71 5272429
e-mail: m.langbroek@arch.leidenuniv.nl
http://home.wanadoo.nl/marco.langbroek/
=============
(13) QUANDRANTID PARENT: A RESPONSE
>From Duncan Steel <D.I.Steel@salford.ac.uk>
Dear Benny,
There are several points on which I disagree with Marco Langbroek
in his
discussion of the origin of the Quadrantid meteor shower. Here
just a few
will be highlighted.
(a) Marco wrote:
>I disagree with Duncan Steel however, about the
"firmness" of this proposed
>connection between Machholz 1 and the Quadrantids. This
connection demands
>that the stream should be old, because the models which
generate the
>connection base this on modelling of the cometary orbit back
to 5000 years
>ago, when the comet should have shed the dust that now is
visible as
>Quadrantid meteors.
This statement is incorrect with regard to the age of the stream.
For
example, numerical studies published by J.Jones and W.Jones
(MNRAS, 261,
605-611, 1993) indicate that P/Machholz 1 may have been captured
by Jupiter
about 2,200 years ago, and they found that "there has been
sufficient time
for the resulting stream to produce most of the features of the
presently
observed Quadrantid/Arietid/Southern delta-Aquarid complex."
(b) Marco wrote:
>However, the Quadrantids definitely are a very young stream,
not an old
>stream.
This is an example of why I have in the past been pedantic over
the confused
usage of the terms "meteoroid stream" and "meteor
shower." The "Quadrantids"
is a meteor shower; it results from the intersection of the Earth
with a
particular meteoroid stream. One might say that the Geminids is a
young
meteor shower, in that it was not observed until the mid-19th
century, but
the stream producing the Geminids is clearly much older.
Similarly the
profile of the Quadrantids does not
necessarily tell us much about the age of the responsible stream.
(c) Continuing:
>In our 1997 Astronomy & Astrophysics paper (ref. below),
we reported that
>the spread in the high accuracy multistation photographic and
video
>orbits of the Quadrantids (35 photographic and 29 video
orbits) which our
>Dutch Meteor Society gathered, precludes that this stream is
caused by 'old'
>dust. The dispersion in orbital elements among our meteor
sample is just too
>small for that. We estimated that the dust that creates the
sharp main
>activity peak of this stream should not be much older than
500 years (the
>wider low level background activity upon which the main peak
is superposed
>could be older dust though but is too ill sampled to allow
definite
>statements on that).
This interpretation of observational data is based upon certain
assumptions
that may or may not be valid. Broadly-speaking the interpretation
is similar
to that of the recent modelling of the Leonid outbursts: lack of
dispersion
is assumed to indicate a youthful filament of a stream. The
assumption that
this also applies to these Quadrantid observations is just that:
an
assumption. In fact, modelling of the spreading of the stream
produced by
the comet in question shows the persistence of certain
concentrations (e.g.
see Figure 3 in Jones & Jones, cited above). That is, unless
the meteoroids
(observed as meteors by this DMS group) had very similar orbital
elements,
they would not have intersected the Earth at that time. The low
dispersion
under that circumstance is not directly linked to the time since
the
meteoroids were released from their parent, and so the underlying
assumption
is invalid.
(d) Continuing again:
>This precludes the hypothesis that the stream is
>connected to dust shed by comet 96P/Machholz 1 as much
as 5000 years ago.
>This in turn rules out comet 96P/Machholz 1 as the parent for
the
>Quadrantids, contrary to Steel's assertion that this is
"rather firmly
>established".
Here I simply mention that rejection of the hypothesis that
96P/Machholz 1
is the parent for the Quadrantids implies that its fitting
against not only
the Quadrantids but also the other showers that the stream
produces is a
matter of chance, the likelihood of which is very slim. This
would
offend against William of Ockham (who of course is not
infallible).
(e) Marco wrote:
>The Quadrantids are in a high inclination orbit, and so must
be
>their parent...
This is simply untrue. The inclinations of the stream producing
the
Quadrantids and also (of course) 96P/Machholz 1 vary between
about 10
degrees and almost 90 degrees: see Figure 6 of Jones & Jones,
or Gonczi,
Rickman & Froeschle, MNRAS, 254, 627-634, 1992. Such a spread
is attained
within 1000 years after release.
In all of this, the solution to the "problem", as such,
is the way in which
the comet and meteoroids evolve dynamically when very close to
the 2:1
jovian mean-motion resonance.
The trouble with trying to jump from meteor shower observations
to a general
picture of the whole stream is that showers only occur at certain
sets of
orbital elements producing a node at 1 AU. There are other parts
to every
stream that are separated from us in space and time which may not
be sampled
through meteor techniques.
I will leave it to someone else to stake a claim for Comet 1491 I
being the
Quadrantid parent.
Kind regards,
Duncan Steel
==============
(14) ASTEROID 2001 YB5
>From Larry Robinson <lrobinsn@ix.netcom.com>
Dear Benny:
This is the second time I write to you regarding 2001 YB5. The
first time
was on January 1, when this object was still listed on NEODys and
the MPC as
a Virtual Impactor.
In CCNet today I see at least two references to 2001 YB5 being
discovered in
early December and another saying December 12. I am not sure
where these
authors are getting their dates, but the observations of this
object are
easily obtained by anyone with a computer and internet
access. This object
was discovered on December 27 by 644 Palomar Mountain NEAT and
immediately
followed up by other stations. Later it was discovered on
previous plates
taken at observing station 608 Haleakala-NEAT/MSSS on December 26
by 118
Modra where observers J. Toth, S. Gajdos got the third night and
the impact
solution was announced by Spaceguard Central Node. So we did not
have 25
days warning on this one before closest approach or potential
impact. We had
only half that time!
Only after further observations by 734 Farpoint, 649 Powell, 413
Siding
Spring, and several others was the all clear sounded on this
object. That
occurred at about noon on January 2, EST or 17:00UT on January 2
for the
astronomically inclined. Had it not been cleared, we would have
probably
only have had one week's notice before an impact event that would
have
changed all of our lives forever.
Many observations have followed these. Here are all of the
observations from
the Minor Planet Ephemeris Service at
http://scully.harvard.edu/~cgi/MPEph2.COM
It is not hard to get the facts on these things. At least right
now it is
public knowledge, if you take the time to look.
A few obvious questions occur to anyone, such as what would the
procedure
have been, if those follow up observations had confirmed an
impact solution?
Who would make the call, to whom, and when? Did anyone notify
anybody this
time, even to let them know there was a remote possibility of an
impact on
January 7? Is there a formal procedure for notification? What
could be done
in a case like this?
Larry Robinson
=============
(15) TSUNAMI DANGER FROM A 300m ASTEROID
>From Michael Paine <mpaine@tpgi.com.au>
Dear Benny
Worth Crouch and David Whitehouse refer to the tsunami danger
from a 300m
asteroid striking the ocean. From my investigations of this
topic, a 300m
asteroid would produce a tsunami with a 10m run-up height at a
distance of
no more than 300km from the impact. This is based on the
theoretical work of Chuck Mader and David Crawford and advice
from Chuck
Mader that a typical coastline has a run-up factor of 5 or less
(not 40
sometimes quoted in books). Hence the tsunami effects from a 300m
impactor
have a similar range to the direct blast effects. They do not
represent a
threat across an entire ocean basin.
See http://www4.tpg.com.au/users/tps-seti/spacegd7.html
for a discussion of
impact tsunami. I also have a paper published in The Science of
Tsunami
Hazards http://epubs.lanl.gov/tsunami/ts173.pdf
(9.4Mb PDF file)
regards
Michael Paine
MODERATOR'S NOTE: Dear Michael, Many thanks for your timely
reassurance. In
all fairness, I should point out that Worth Crouch did comment
very
specifically, saying that "if the impact were in the right
place in the
Atlantic, off the coast of the United States, all U.S. coastal
cities would
be wiped out making the September 11 disaster seem
insignificant..." While
certainly not "all" coastal cities would be "wiped
out", I think the affects
described by both Worth and David Whitehouse are not that wide
off a
realistic scenario. I don't think we would like to experience
what a
300-400m object hitting the Atlantic Ocean might cause.BJP
===========
(16) HAPPY BIRTHDAY PROFESSOR HAWKING!
>From Andy Nimmo <andy-nimmo@ntlworld.com>
"Hi Everybody,
As most of you on this web site will be aware, some time back
Professor
Stephen Hawking very kindly granted the SDC permission to use his
name in
support of our 'Get A Briton In Space' campaign. On Tuesday 8th
January 2002
Professor Hawking is 60 years of age.
To celebrate, we decide to send him a card on all the SDC's
behalf, and
ASTRA space artist Andy Paterson very kindly agreed to paint him
a painting
as a gift. Unfortunately the painting he painted was too large to
travel, so
instead he decided to substitute a smaller and fairly well known
painting of
his, entitled 'Exploring a Ringed Planet'. This was painted in
1998 and has
appeared in exhibitions both in halls and on the web.
It so happens that SDC web site member, Yuki Takahashi, is
attending a
symposium in Cambridge with Professor Hawking on Friday 11th
January, and he
has agreed to take the card and painting and give them to
Professor Hawking
at this event.
For those of you who are interested, I have opened an album in
our
'Pictures' section with 5 pictures. These are 1: Exploring a
Ringed Planet,
the painting we are gifting to Professor Hawking, 2: the Birthday
card
cover, 3: the inside first page with some signatures, 4: the
inside centre
pages with more signatures and the names of all of our member
groups as of
early December, and 5: A young astronaut - pinched from Yuki's
web site.
Web sites that may also be of interest are:
http://www.hawking.org.uk/home/hindex.html
and
http://www.ugcs.caltech.edu/~yukimoon/
So far as I'm aware, Andy Paterson doesn't have a web site
himself, but an
exhibition of his work including the painting we are gifting,
appears on:
http://homepage.ntlworld.com/andy-nimmo/Webpage9a.htm
Best wishes, Andy."
---If you'd like to see the card please feel free to go to the
SDC
Smartgroup (http://www.smartgroups.com/groups/sdcv
) 'Pictures' section and
open the album concerned. To see a larger version of any of the 5
pictures
in the album simply click on the picture. If you wish, you would
be welcome
to join the SDC web site list. It doesn't cost anything.
Many thanks to Danny Kane and ASTRA Airdrie for organizing the
card for us,
to Andy Paterson for donating the picture - and refusing to take
a penny for
it, to Douglas Easton for scanning everything in for us, and to
Yuki
Takahashi for agreeing to take both card and picture down to
Professor
Hawking.
Since the scanning, one of two further signatures will be added -
Yuki's for
example, and I gather he is also going to try to get Professor
Archie Roy's
and Virgiliu Pop's and possibly others at Glasgow University to
add theirs.
A Happy New Year to All of You!
Andy Nimmo, (SDC Chairman).
============
(17) BIODIVERSITY OR BIOMASS?
>From Hermann Burchard <burchar@mail.math.okstate.edu>
Dear Benny,
A note from the NSF by Michelle R. Edwards (CCNet Jan 7)
concerning work by
James Kirchner of UC-Berkeley reported in NATURE, seems to
elevate
BIODIVERSITY over BIOMASS in extinctions and recovery in a
strange way when
she states: "...history of life on Earth is a series of
booms and busts.
But while the busts, or extinctions, can be either sudden or
gradual, the
booms, or diversifications, of new organisms rarely occur
quickly..we can't
expect the biosphere to just bounce back."
This seems to me to be putting the cart before the horse. Would
not
extinction = "bust", and a "boom" = the
biosphere bouncing back, consist
primarily in depletion and replenishment of biomass sufficient to
either
disrupt or sustain a foodchain?
First of all, plants can live on water, air, and sun, and don't
depend much
on diversity. Then, even for animals, biodiversity would come
into play only
as a secondary effect. For example, right after Chicxulub most of
the
plant-eating dinosaur species probably still had a few living
members foraging for plants which, although available in large
numbers of
species, were quickly wilting.
-- I appreciate his points about niches and houses of cards and
all that,
but millions of species of very few live specimens would not make
a
biosphere, it seems to me. Possibly in some cases (crocodiles,
humans
protected by caves) cannibalism might have given a competitive
edge,
sadly.
Regards,
Hermann
=============
(18) STONEHENGE: AN EARLY IMPACT WARNING DEVICE?
>From Pavel Chichikov <fishhook@erols.com>
Dear List and Dr. Peiser,
I'll be in Wales and Ireland in April - early May - for
preliminary research
on a layman's book about Neolithic and Bronze Age monuments.
I'm intrigued by Dr. Steel's speculation concerning Stonehenge as
an early
warning device, and would like to ask discussion group members to
share with
me their own speculations, meditations, hunches etc. concerning
this idea.
I'd be most grateful for any communication, including arguments
against.
Wouldn't it be ironic, though, if our Neolithic forebears had
arrived at the
idea of a Spaceguard some millennia before we did?
Layman's question: Are there angles of approach which give only a
few days
of warning, rather than weeks, months and years?
All best wishes,
Pavel
fishhook@erols.com
[please remember - two 'aitches']
Mailing address:
c/o Grey Owl Press
PO Box 5334
Takoma Park, Maryland 20913
USA
-------------------------------------------------------------------
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CCNet ESSAY, 8 January 2002
GOING INTO THE WATER: A SURVEY OF IMPACT EVENTS AND THE COASTAL
PEOPLES OF
SOUTH-EAST NORTH AMERICA, THE CARIBBEAN, AND CENTRAL AMERICA
http://abob.libs.uga.edu/bobk/ccc/ce010702.html
By E.P. Grondine epgrondine@hotmail.com
INTRODUCTION: SURVEY SCOPE AND TECHNIQUES USED
Hello Benny,
In my survey last year of impact events and the Native American
peoples of
South-East North America, I mentioned several items and then let
them pass,
as they laid outside of the scope of that survey proper. Nearly
all of those
items pertained to the coastal peoples of the region, and there
were good
reasons for this limitation of scope: due to both the maritime
nature of
these peoples' cultures, as well as to the ecological niches in
which they
lived, it is impossible to consider these peoples outside of the
wider
context of the peoples who lived during the same period on the
islands in
the Caribbean Sea and along the coasts of Central America.
This essay is a first attempt to extend that earlier survey into
those
coastal areas. Unlike last year's survey, where site visits
were followed
up with an extensive literature search, this survey is limited
solely to a
literature search. My opinion is that the technique used for the
first
survey is much more efficient, as site visits allow for a
familiarization
with the pottery sequences, iconography, and technologies, those
items which
are really the key to population movements, and thus to a full
understanding
of the evolution of any oral or written records which remain. But
sadly yet
once again, as in preceding years, the folks at the MacArthur
Foundation
have failed to declare me a genius and send me a large amount of
cash, so
due to the costs involved in visiting sites over such a wide
area, a
literature search was the only technique available to me. Should
someone
wish to fund visits to sites in the Caribbean and Central America
they would
undoubtedly improve the survey to a considerable degree; the
general
consensus seems to be that site visits to the Caribbean and
Central America
which are taken in the middle of the North American winter are
optimal.
Before starting any survey we might reasonably expect, given the
data which
has been recovered up to this time from other areas of the Earth,
that over
a suitably long period of time the peoples living in these
coastal areas
would also have been affected by impact events. Indeed, several
Conference
participants have been arguing for quite some time for the
existence of a
Holocene-start impact event which affected this area. The first
part of this
survey will be a limited review of some anthropological materials
pertaining
on this possible impact event, though this will not be a detailed
work.
Also included in this first part of the survey will be a brief
mention of a
possible mega-tsunami produced geological structure, the Puuk
Foothills of
the Yucatan.
The bulk of this survey will focus on a mega-tsunami event ca.
1150-1050
BCE, which fairly well devastated those living along the coasts
of this
area. In order, the second part of the survey will cover
the peopling of
the areas which the impact affected, and describe the lives of
those who
died in the event. The third part of the survey will cover the
preservation
of later historical records and folk memories of the
catastrophe. The
fourth part will set out some of the historical and myth
materials which
have survived, including also some materials which appear to
refer to the
earlier Rio Cuarto impact event.
In closing this introduction, I want to state that this has been
the survey
from hell. These peoples were completely warped by this impact,
and had a
world view which was both unified and completely distinct from
that of
western Europe. While the world view of the South East Native
American
peoples resonated with me to a certain degree, as I am familiar
with their
lands, the world view of the peoples of the coastal regions never
has.
Having worked through the material on them to the extent which I
have, I
suspect that anthropology would be better as a science if
anthropologists
were generally required to work on peoples with which they did
not identify,
so as to reduce the problem of identification.
Given this far far far different world view, it appears that it
normally
takes around 20 years for an anthropologist to master these
materials to the
point at which they can make substantial contributions to the
field. But in
the case of these impacts events, the cultural points are gross,
to put it
succinctly, and my ambitions extend no further than that I may
direct those
trained in these cultures to that evidence, without committing
too many
blunders along the way.
Finally, it helps if one is not distracted by current events.
That said,
here goes...
FULL ESSAY at http://abob.libs.uga.edu/bobk/ccc/ce010702.html
