PLEASE NOTE:
*
CCNet 67/2001 - 14 May 2001
---------------------------
"You may have heard the sad news that Douglas Adams passed
away last
Friday. By accident on the same day the naming of minor planet
(18610)
Arthurdent was announced by the Minor Planet Center. We wanted to
make Mr.
Adams a joy, but did never dare to think that he wouldn't be able
to
receive this surprise, when we sent our name proposal to the MPC
a few
months back. The name was proposed by Felix Hormuth of
Starkenburg
Observatory, who discovered this minor planet on 1998 Feb. 7
--Reiner Stoss, Starkenburg Observatory, 14 May 2001
(18610) Arthurdent = 1998 CC2
Discovered 1998 Feb. 7 at Starkenburg
Observatory. The earthling
Arthur Dent is confronted with the adversities of life, the
universe
and everything in a highly amusing and entertaining way in
Douglas Adams'
famous five-volume trilogy "The Hitch Hiker's Guide to
the Galaxy".
(1) ASTEROID "ARTHURDENT" NAMED ON DAY OF DOUGLAS
ADAM'S DEATH
Reiner M. Stoss <rstoss@hrz1.hrz.tu-darmstadt.de>
(2) SCI-FI AUTHOR & CCNet MEMBER DOUGLAS ADAMS DIES
BBC News Online, 12 May 2001
(3) ASTEROID MAY HAVE FLUNG PIECES TO EARTH, DINOSAURS TO MOON
& MARS
Florida Today, 12 May 2001
(4) ESCAPISM: SPACE COLONIES 'KEY' TO SURVIVAL FROM TERRORISM
The Age, 14 May 2001
(5) WILL THE EARTH SHARE THE FATE OF SATURN?
Andrew Yee <ayee@nova.astro.utoronto.ca>
(6) SPACEGUARD & EXTINCTIONS
David Morrison <dmorrison@arc.nasa.gov>
(7) BRIGHTENING COMET C/2001 A2 (LINEAR)
Space Weather News for May 12, 2001
(8) ALIEN VISITORS
New Scientist, 11 May 2001
(9) NEW RADIO TELESCOPE AMKES FIRST OBSERVATIONS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(10) RE: THE END IS SHY
Ian Lyon <ilyon@fs1.ge.man.ac.uk>
(11) MARS TROJANS
Duncan Steel <D.I.Steel@salford.ac.uk>
(12) SPECIES SURVIVAL
Leon Neihouse <neihouse@gwi.net>
(13) INTERNATIONAL EMERGENCY CONDITION
Andy Smith <astrosafe@yahoo.com>
===========
(1) ASTEROID "ARTHURDENT" NAMED ON DAY OF DOUGLAS
ADAM'S DEATH
From Reiner M. Stoss <rstoss@hrz1.hrz.tu-darmstadt.de>
Dear Dr. Peiser,
You may have heard the sad news that Douglas Adams passed away
last Friday.
By accident on the same day the naming of minor planet (18610)
Arthurdent
was announced by the Minor Planet Center.
We wanted to make Mr. Adams a joy, but did never dare to think
that he
wouldn't be able to receive this surprise, when we sent our name
proposal to
the MPC a few months back.
The name was proposed by Felix Hormuth of Starkenburg
Observatory, who
discovered this minor planet on 1998 Feb. 7
Best Regards,
Reiner Stoss
Starkenburg Observatory
(18610) Arthurdent = 1998 CC2
Discovered 1998 Feb. 7 at Starkenburg
Observatory.
The earthling Arthur Dent is confronted with
the adversities of life,
the universe and everything in a highly amusing and entertaining
way in
Douglas Adams' famous five-volume trilogy "The Hitch Hiker's
Guide to
the Galaxy".
============
(2) SCI-FI AUTHOR & CCNet MEMBER DOUGLAS ADAMS DIES
From the BBC News Online, 12 May 2001
http://news.bbc.co.uk/hi/english/uk/newsid_1326000/1326657.stm
Douglas Adams died of a heart attack
Author Douglas Adams, who wrote The Hitchhiker's Guide to the
Galaxy, has
died suddenly aged 49.
Mr Adams died on Friday morning in Santa Barbara, California,
following a
heart attack, said his spokeswoman Sophie Astin.
The author became a household name when the cult science fiction
novel was
turned into a BBC TV series.
Prominent figures at the BBC, who worked with Adams on many
projects, have
spoken of their shock and sorrow at his death.
Alan Yentob, the BBC director of drama and entertainment, said:
"Douglas was
a big character who will be hugely missed by a host of friends
and millions
of fans around the world.
"He was a gifted writer; a one-off talent who managed to
combine fantasy and
humanity in books which enthralled generations of readers. We'll
miss him
enormously."
The BBC's head of comedy, Geoffrey Perkins, who produced the
original
Hitchhiker's radio series, said: "I'm absolutely devastated.
I've known
Douglas for 25 years. He was absolutely one of the most creative
geniuses to
ever work in radio comedy.
"He probably wrote one of the greatest radio comedy series
ever; certainly
the most imaginative.
Film
"For somebody who was so involved in breakthroughs in new
developments in
technology, it's a tragedy that he's died before most of the
things he's
talked about have come about."
Ashley Highfield, the BBC director of new media, who worked wth
Adams on his
website, said: "I've been a huge fan of Douglas and working
with him on the
h2g2 website was the culmination of childhood dreams.
"He was pretty unique in being innovative in media after
media - from radio
to the web. He was still coming up with more new ideas than
almost anyone
I've met.
"His brainchild - the h2g2 website - which the BBC has taken
forward, is
groundbreaking in enabling an online encyclopaedia to be created
by the
people for the people."
Adams was born in Cambridge in 1952 and educated in Essex before
returning
to Cambridge to study at St John's College.
Adams's novel was turned into a BBC series
His career included work as a radio and television writer and
producer
before his life was changed by the publication of The
Hitchhiker's Guide to
the Galaxy in 1979.
The satirical tale chronicled the journey of alien Ford Prefect
and his
human companion Arthur Dent throughout the universe after the
destruction of
Earth.
It centred around the search for an answer to life, the universe,
and
everything - which turned out to be 42.
The novel went on to sell more than 14 million copies worldwide
and was
followed by the sequels The Restaurant at the End of the
Universe, Life, the
Universe and Everything and So Long and Thanks For All the Fish.
In recent years the author had been working on a Hitchhiker's
Guide movie.
There was much speculation about who would play Arthur Dent, with
Hugh
Laurie, Rowan Atkinson, Jim Carrey, Ben Affleck and even Bruce
Willis said
to be in the running.
Adams married Jane Belson in 1991 and had a daughter, Polly, in
1994.
Copyright 2001, BBC
============
(3) ASTEROID MAY HAVE FLUNG PIECES TO EARTH, DINOSAURS TO MOON
& MARS
From Florida Today, 12 May 2001
http://www.flatoday.com/news/space/stories/2001a/may/spa051201a.htm
By Steven Siceloff
FLORIDA TODAY
CAPE CANAVERAL, Fla. - Dinosaur hunters who search the badlands
of America
for traces of extinct creatures may want to take their search to
the moon or
Mars.
So says Doug Shull, an Air Force reserve major with the 45th
Space Wing who
presented his theory last week at the 38th Space Congress.
Shull suggests that pieces of Earth may have been blown off the
planet by
asteroid strikes millions of years ago, and those pieces - along
with pieces
of dinosaurs - may have landed on the moon or Mars.
The asteroid thought to have killed off the dinosaurs, for
example, was six
miles wide, weighed a trillion tons and created a shock wave that
traveled
1,200 miles in three minutes. It is thought to have slammed into
what now is
Mexico, creating the Yucatan Peninsula and the Gulf of Mexico
more than 65
million years ago. Researchers theorize the blast and its shock
wave tossed
up all soil and rocks down to the bedrock for hundreds of miles
around.
"That's just scouring the land, not just blowing it up, but
scouring it,"
Shull said.
Researchers during the 1980s thought the impact simply pulverized
everything
beneath it. Later analysis showed that rocks and other remnants
would be
flung off the planet if the asteroid was large enough.
Many of the chunks would have landed in other parts of the world,
Shull
said. But other pieces likely blended with a cosmic cloud around
the Earth
that the moon regularly passed through.
The pieces from the impact 65 million years ago could be parts of
dinosaurs,
plants and other prehistoric animals in the path of the plunging
asteroid.
Shull said the remains could be well-preserved, sitting on the
airless moon,
where neither fossilization nor biological degradation would harm
them. That
means some bones still might have muscle or skin attached.
Paleontologists
long have sought such clues.
There is some precedent for all this: The Apollo astronauts
recovered rocks
on the moon that matched some rocks on Earth. And Martian meteors
have made
their way to Earth.
But paleontologist Jack Horner of the Museum of the Rockies, a
consultant to
the film "Jurassic Park," waved off the theory.
"I'd put that as the same plausibility as Martians coming
down here and
getting them," Horner said from his Montana office.
Horner's assessment did not surprise Shull, who has worked with
physicists
and engineers on the theory but not dinosaur specialists.
"He's a great paleontologist," Shull said. "Now,
what he knows about
asteroid physics, I don't know."
Shull continues to study and work on his theory. He is building a
computer
program to model how soil would fly after an asteroid collision.
When astronauts return to the moon or go to Mars, he said,
paleontologists
who know what to look for will be needed.
Copyright 2001, Forida Today
===========
(4) ESCAPISM: SPACE COLONIES 'KEY' TO SURVIVAL FROM TERRORISM
From The Age, 14 May 2001
http://www.theage.com.au/news/2001/05/14/FFXM2SUONMC.html
By ANDREW HEASLEY
TECHNOLOGY REPORTER
In the next century, man-made hazards such as germ terrorism will
drive
humans to colonise space for survival, Britain's Astronomer
Royal, Sir
Martin Rees, said yesterday.
"There are various ways waiting for us to snuff ourselves
out, by design or
misadventure," he said - and the key was to colonise space
before disaster
struck.
"Once you have life spread beyond Earth, the species itself
will be above
being vulnerable to any man-made disaster. It's what I call the
cosmic
insurance policy."
Sir Martin and US-based Australian astronomer Jeremy Mould were
two
star-gazers who spoke on "The Beginning and the End of the
Universe" for the
Alfred Deakin Federation lectures in Melbourne yesterday.
Australia had made a significant contribution to astronomy, Dr
Mould said,
from early colonial telescopes to a stake in the international
Gemini
project - building two new observatories, in Hawaii and Chile.
The past year was a big one for Australian astronomers, who had
contributed
to measurements of the density, expansion and acceleration of the
universe,
he said.
According to Sir Martin, the universe is 10 billion light-years
across and
consists of 4 per cent atoms, 25 per cent "dark matter"
and the remainder
"mysterious latent energy".
The "Big Bang" 15 billion years ago scattered
chemistry, physics and energy
into space. This created black holes, dark matter, radiation and
atoms, and
eventually stars, suns, planets and ultimately humans, he said.
Sir Martin further suggested ours may not be the only universe.
"Our universe could be just an episode, one facet, of the
infinite
multiverse," he said.
"Some universes may resemble ours. Different domains, quite
disjoint from
ours, would evolve in different ways, perhaps being governed by
different
physics."
Copyright 2001, The Age Company
===========
(5) WILL THE EARTH SHARE THE FATE OF SATURN?
From Andrew Yee <ayee@nova.astro.utoronto.ca>
Informnauka Agency
Moscow, Russia
Contact:
Tatiana Pitchugina, 7-095-2675418, textmaster@informnauka.ru
11.05.2001
Space ecology was one of the topics for discussion at the
International
Space Conference "Space without weapons - the arena of
peaceful cooperation
in the 21st century" held in Moscow on April 12, 2001. Among
the problems
the scientists discussed was the near-earth space pollution by
the rockets
and space vehicles fragments.
WILL THE EARTH SHARE THE FATE OF SATURN?
Is it possible that space exploration will result in the
formation of a ring
around the Earth similar to the Saturn ring? Most likely human
beings will
not be able to create such a dense object. However, all this
debris can
severely impede space flights in future, as plenty of objects
brought out
into space would stay in the near-earth orbit for hundreds and
even
thousands of years. Therefore, Russian scientists believe that
the
spaceships design needs urgent modifications to ensure their
return to the
Earth.
The fate of an object in space depends on the altitude it is
located at.
Space stations rotate [sic] at the height of 400-500 kilometers.
The
atmosphere still exists there and it slows down an object. The
object looses
its speed and within a couple of years enters dense atmospheric
layers where
it fully burns out. A lot of objects happen to rotate beyond the
atmosphere.
The scientists have found out two peak altitudes the objects are
concentrated at about 800 and 1500 kilometers. Another group of
objects is
located in the geostationary orbits -- about 36 thousand
kilometers above
the Earth surface.
As there is no atmosphere to affect flights there, the object
will continue
to rotate around our planet for a long time. The objects
concentration there
is accountable -- it is at these heights that various
communication
satellites and other useful devices are located. The more objects
are in
orbit, the higher the risk of collisions is.
During the 40-year period of active space research an operating
satellite
once has happened to collide with a large object, resulting in
the loss of
the French space satellite. "Mir" station and American
"Shuttle" spaceships
have undertaken several maneuvers to avoid the clashes. Even the
International Space station that is not fully operational yet has
already
conducted an escape maneuver. However, in terms of flight safety
the risk of
a dangerous collision with a space object is very high: for a
single
operational module of this station it makes 5-10% within the
15-year
estimated operation period.
Generally, space debris can be divided into two categories: the
objects,
which can be seen through a telescope and the objects too small
for regular
observations. It is easier to work with the first category (the
objects
being more than 20 centimeters in size) because they are
registered in the
catalogues, their number slightly exceeding 8,500. Half of these
objects
were created as a result of satellite and carrier rocket
destruction.
Astronomers have altogether recorded more than 150 explosions in
space.
The debris that can not be seen through a telescope is more
difficult to
deal with. Its particles sizing millimeters and flying at the
speed of 10
kilometers per hour are capable to damage a satellite or a space
station:
spoil a solar battery or, even worse, to make a hole in a fuel
tank. But
these particles are incalculable. Therefore the scientists are
developing
simulators which allow to forecast the behavior of such small
objects. The
countries involved provide for different simulators, the
computation results
varying by dozens of times. Our scientists consider these
variations to be
acceptable, such deviations are quite insignificant when
computing millions
of objects, particularly millimetric debris particles flying in
the
near-earth orbit.
Applying their model, the specialists from the Center for Space
Observations
(Rosaviakosmos) have investigated future development of the
near-earth space
pollution process. They have reviewed five scenarios:
1 - everything remains unchanged;
2 - the number of explosions reduces by half;
3 -the number of carrier rockets in space reduces by half;
4 - all (or half) satellites and carrier rockets return to the
Earth;
5 - all the above measures are taken simultaneously.
It has appeared that in case of scenarios 1-3 the debris volume
in orbit
will grow up by 2-3 times by the 22nd century. Provided all the
above steps
are implemented (the number of explosions goes down and all
flying objects
return to the Earth), this will allow to reduce the debris volume
by 1.5
times within the next hundred years. Foreign scientists have made
similar
conclusions.
Therefore, the March meeting of the International Committee on
Space
Contamination adopted a resolution on the necessity to bring
order to the
near-earth-space. The space flight standards for all countries
should
include a requirement for the space devices developers to ensure
the objects
return from the orbit.
Unfortunately, there is no quick way to achieve it, because this
entails
immediate expenses growth. First of all, it is necessary to
change the
carrier rockets design so that the waste stages descended to the
lower
orbits. Secondly, additional fuel will be needed for each
satellite to allow
its descend to the atmosphere. However, the space pollution is
close to
critical, so these expenses appear to be unavoidable.
***
For additional information:
Andrei Nazarenko
Center for Space Observations (Rosaviakosmos), Moscow
+7 (095) 334 92 70, nazarenko@iki.rssi.ru
============
(6) SPACEGUARD & EXTINCTIONS
From David Morrison <dmorrison@arc.nasa.gov>
NEO News (5/12/01) Spaceguard & Extinctions
Dear Friends & Students of NEOs:
This edition of NEO News discusses two different subjects. First
is a brief
essay on the meaning of the often-quoted NASA Spaceguard Goal to
find 90% of
NEAs larger than 1 km diameter by 2008. The second is a press
release and
two journalist comments on recent work by Peter Ward and
colleagues
suggesting that the Triassic-Jurassic mass extinction of 200
million years
ago was sudden and catastrophic. There is no direct evidence of
an impact,
but the new work is apparently consistent with an impact-caused
global
catastrophe.
Welcome to 97 new subscribers to NEO News!
David Morrison
=====================================================
ORIGIN AND MEANING OF THE NASA SPACEGUARD GOAL
David Morrison (with inputs from Alan Harris and Clark Chapman)
One often sees references to the "NASA Spaceguard Goal"
of detecting 90% of
NEAs larger than 1 km diameter within a decade. Following are
some
clarifications and historical context for this goal.
* Why NEAs (near-Earth asteroids) and not NEOs (all near-Earth
objects)?
There are two reasons. First, only NEAs (including the
short-period comets)
come past the Earth frequently enough to be
detected in a sky survey like Spaceguard, which aims to find any
hazardous
objects decades before they pose a direct threat to the Earth.
Second, we
have no way of knowing the number of comets that may eventually
pass near
the Earth (become NEOs). There may be billions of them out in the
distant
Oort Cloud, but with individual periods of millions of years,
they actually
pose a smaller threat than the nearby NEAs. What really matters
is not how
many there are, but how many cross the Earth's orbit every year.
So NEAs are
the only population we can effectively survey, and they also
account for
most of the impact risk.
* Why 1 km diameter? Because objects 1 km or larger represent the
greatest
hazard. Studies carried out at the time of the original NASA
Spaceguard
Survey Working Group in 1992 identified a threshold at energies
near 1
million megatons where an impact had global, not just local or
regional,
effects. As first discussed in Chapman & Morrison
("Impacts on the Earth by
asteroids and comets: Assessing the hazard" Nature
367:33-40, 1994), the
individual risk from impacts (the numerical hazard) jumps by
roughly an
order of magnitude for energies at and just above this threshold.
More
recent work suggests that this threshold for
civilization-threatening
impacts is probably nearer 2 km rather than 1 km diameter, but
the
Spaceguard objective of detecting 1-km NEAs seems like a
reasonable and
rather conservative figure.
* Why don't we measure diameter directly? Instead we measure
brightness,
expressed by an absolute magnitude called H. The practical
objective is to
find the NEAs brighter than H=18, which is approximately
equivalent to 1 km
diameter for an average asteroid. Of course, not all asteroids
will have
this average reflectance, but it would not be cost-effective to
try to
measure diameters of most NEAs, since this would require
substantial effort
with very large telescopes. If we want to be sure to get nearly
all the
darker 1-km asteroids, it is easiest just to extend the survey to
fainter
magnitudes, perhaps to H=18.5.
* Why only 90%? Because that is a reasonable metric. We can't
ever get 100%
(or at least we can't be sure of having found them all). Also,
90% is enough
to reduce the hazard from the undiscovered NEAs below the risk
from long
period comets.
* When is the ten year deadline reached? The specific 10-year
timescale was
mentioned in Congressional language in 1994, when the US House of
Representatives asked NASA for a program plan to carry out the
Spaceguard
Survey. In Congressional hearings in 1998, NASA officials adopted
the
Spaceguard Goal. Measuring from that time, the 90% goal should be
reached by
2008.
This is a brief summary of how the goal was developed. It came
initially
from the 1992 NASA Spaceguard Survey Report, the timescale was
articulated
by the US Congress in 1994, and the goal was formally accepted by
NASA in
1998.
There are two additional important points to be made.
1) We should all understand that the Spaceguard Survey is not
limited to
NEAs larger than 1 km diameter. NASA has been accused from time
to time of
"ignoring smaller NEAs", but this is not the case.
Unlike fishing, where you
"throw the small ones back," we collect and follow up
everything within the
capabilities of the observing systems without regard to size (or
brightness). Today we are finding about twice as many NEAs
smaller than 1 km
as we do those larger than this value. It is a fact of geometry
that the big
ones are easier to find than the smaller ones, so we can expect
to reach
completion (or 90% completion) of larger objects sooner than
smaller ones.
Adding more or bigger telescopes does not change the fact that we
will find
all the big objects sooner than we will find all the smaller
ones, however
long that time may be.
2) The "Spaceguard Goal" can be regarded as a metric
for tracking progress
of the survey, irrespective of arguments over the cost-benefit of
other
levels of surveying. It is not a goal in the sense that we should
stop
surveying when we reach 90% completion of NEAs of H brighter than
18. In
order to make a quantitative statement of progress, we must
define specific
parameters, namely some brightness limit to count and some
completeness
level versus time for that size. We choose H = 18, 90%
completeness, and a
target of achieving that in ten years. We could as well choose H
= 19.5,
which for average asteroids corresponds to 500 m diameter, and
measure
progress with that metric. Assigning priority to
"larger" or "smaller"
objects is a moot point. Many would agree there are valid reasons
that we
should eventually take care of the horrific tsunami-makers, which
means
going down to 500 m or even smaller. But there is no practical
way to
discover only larger or only smaller NEAs. Larger telescopes do
the job
faster, and this is increasingly important as we go to smaller
NEAs. But you
get what you get, and various survey strategies make little
difference in
the makeup of the catch, just the total numbers.
===================================================
PRESS RELEASE ON TRIASSIC-JURASSIC MASS EXTINCTION
University Of Washington
May 10, 2001
Collapse of simple life forms linked to mass extinction 200
million years
ago
A mass extinction about 200 million years ago, which destroyed at
least half
of the species on Earth, happened very quickly and is
demonstrated in the
fossil record by the collapse of one-celled organisms called
protists,
according to new research led by a University of Washington
paleontologist.
"Something suddenly killed off more than 50 percent of all
species on Earth,
and that led to the age of dinosaurs," said Peter Ward, a UW
Earth and space
sciences professor.
Evidence indicates the massive die-off was linked with an abrupt
drop in
productivity, the rate at which inorganic carbon is turned into
organic
carbon through processes such as photosynthesis. The waning
productivity
coincided with a sharp decline in radiolaria (included among
protists),
which was the focus of the new research. One example of
productivity, Ward
explained, occurs in the spring when fertilizer washes into
waterways and
triggers large algae blooms. The processes at work in that
scenario were
reversed 200 million years ago, he said.
There is no definitive evidence yet on what caused the demise of
so many
species, Ward said. However, the suddenness of the event is
similar to two
better-known mass extinctions - one 250 million years ago at the
end of the
Permian period that killed some 90 percent of all species, the
other 65
million years ago at the end of the Cretaceous period that sent
the
dinosaurs into oblivion.
The extinction 200 million years ago, at the boundary between the
Triassic
and Jurassic periods, killed the last of the mammal-like reptiles
that once
roamed the Earth and left mainly dinosaurs, Ward said. That
extinction
happened in less than 10,000 years, in the blink of an eye,
geologically
speaking.
Ward is the lead author on a paper detailing the evidence,
published in the
May 11 edition of the journal Science. Others participating in
the research
are James Haggart and Howard Tipper of the Geological Survey of
Canada in
Vancouver, British Columbia; Elizabeth Carter, a researcher at
Oregon's
Portland State University; David Wilbur, a UW oceanography
research
scientist; and Tom Evans, a UW junior in chemistry and Earth and
space
sciences.
The evidence from the extinction was gathered at two sites in the
Queen
Charlotte Islands, off Canada's British Columbia coast.
"These sites are among the most remote places in the
world," Ward said.
"There are no roads anywhere close by. The forests are
virgin old growth,
and the wave action is such that you can't get there by
boat."
Samples from a spot called Kennecott Point, in the northern Queen
Charlottes, and from Kunga Island, about 100 miles to the
southeast, showed
a sharp decline in the presence of organic carbon, even at places
where
levels of inorganic carbon rose. The organic carbon decline
correlated with
the decline of radiolarians, one-celled organisms that serve as a
food
source for a number of marine species.
"These provide the best record of how nasty the extinction
was at this
boundary," Ward said.
The mass extinction 200 million years ago occurred just before
the breakup
of Pangea, which contained all the land on Earth in one
supercontinent. At
the time, the Queen Charlotte Islands - which now lie between 52
and 54
degrees north latitude - were probably on the equator or in the
southern
hemisphere, Ward said.
"These are tropical fossils. There are many kinds of fossils
in these
rocks," he said.
And they tell a story of a calamity that came on with stunning
swiftness.
"This is the first time ever that we can see how sudden this
event was," he
said. "It was very quick, not a long protracted
episode."
Ward now has done research on the last three of the Earth's mass
extinctions
(scientists know of five) and has found that each happened quite
quickly.
Bolstered by a recent astrobiology grant from the National
Aeronautics and
Space Administration, he plans to lead researchers back to the
Queen
Charlottes this summer to look for more clues in the
Triassic-Jurassic
extinction, including potential causes.
###
For more information, contact Ward at argo@u.washington.edu
-----------------------------------------------------
FIFTH WORST MASS EXTINCTION LINKED TO ASTEROID IMPACT
By Robert Roy Britt
Senior Science Writer, SPACE.com
11 May 2001
They call them the Big Five -- a handful of unfathomable mass
extinctions
over the past 500 million years, each estimated to have
obliterated
somewhere between 50 and 96 percent of all species on the
planet.
That much we know, because Earth recorded the mass deaths in
layers of
ancient soil, where crowds of miniscule corpses and other
evidence show
wholesale destruction of the smallest critters, on which larger
animals
depend.
What we don't know, except in one case, is what caused these five
mass
extinctions. Nor is there solid evidence showing how rapidly the
catastrophes occurred.
Such knowledge would be a window not only to the past, but to the
future:
How likely is it that future Earth dwellers will meet with an
inescapable
catastrophic fate, much like the dinosaurs did? And how much time
will there
be to adjust or perish?
While there are no firm answers, a three-page study in the May 11
issue of
the journal Science adds modestly to a mounting stack of reports
suggesting
that asteroids and comets are the leading cause of terrestrial
death,
delivering immensely fatal blows every 100 million years or so
that wipe the
slate of life frighteningly close to clean in remarkably rapid
fashion.
Death came quick
The new study involved the fifth largest known mass extinction,
in which
roughly half of all species were wiped out. It occurred about 200
million
years ago at the boundary of the Triassic and Jurassic Periods in
geologic
history. This T-J boundary, as it is called, marks the dawn of
the
dinosaurs.
In exposed soil layers on islands off the coast of British
Columbia,
researchers found that droves of marine plankton kicked their
watery buckets
at that time. Simultaneously, plants were disappearing rapidly,
as seen in a
quick drop in the rate at which organic carbon was created
through processes
such as photosynthesis.
The extinction occurred in 50,000 years or less, the study's
authors write,
possibly within as few as 10,000 years -- the blink of an eye in
geological
terms. And far faster than previous estimates, which ranged up to
10 million
years.
The paper did not speculate about a cause. But Peter D. Ward, a
University
of Washington Earth and space sciences professor, and lead author
of the
study, told SPACE.com that the evidence makes it look very much
like the
later Cretaceous-Tertiary extinction, or K-T event, which wiped
out the
dinosaurs. The K-T event is the lone mass extinction for which
researchers
have a definitive smoking gun: A crater in the Yucatan Peninsula
excavated
by an asteroid.
"The very rapidity of the [T-J] event and the geochemical
and
paleontological similarity to K-T boundary sections makes it look
like an
impact," Ward said. "My gut feeling is that it was
impact."
But he quickly added that there are other possible causes, such
as rapid
climate change due to heavy volcanic activity.
The world's number-one killer?
Noted University of Chicago paleontologist David Raup told
SPACE.com that
several studies have shown "reasonably good evidence"
linking other mass
extinctions to impacts, but these reports are "almost always
ignored." Raup
produced a study in 1992 suggesting that roughly 60 percent of
all species
extinction may have been caused by impacts.
"I strongly suspect that in a few years this will be the
conventional
wisdom, but it is strangely slow in coming," Raup said.
"Ward's paper and a
couple of others recently on the Permian extinction may get
people to rush
to the other side of the boat."
Other scientists agreed there remain other possible causes for
Earth's
greatest mass extinctions. But the case for cosmic impacts is
growing.
"It seems that several lines of evidence based on new data
and careful
statistical analysis are now showing that at least some of the
great mass
extinctions were geologically instantaneous, leading us to look
for
catastrophic causes such as asteroid impacts," said David
Morrison, an
asteroid researcher at NASA's Ames Research Center in California.
"We know
that impacts have occurred throughout Earth's history, so the
connection
seems plausible." Morrison cautioned that there is
"much research yet to be
done" before the connection can be made clear.
+++++++++++++++++++++++++++++++++++++++++++
NEO News is an informal compilation of news and opinion dealing
with
Near Earth Objects (NEOs) and their impacts. These opinions
are the
responsibility of the individual authors and do not represent the
positions of NASA, the International Astronomical Union, or any
other
organization. To subscribe (or unsubscribe) contact
dmorrison@arc.nasa.gov.
For additional information, please see the
website: http://impact.arc.nasa.gov.
If anyone wishes to copy or
redistribute original material from these notes, fully or in
part,
please include this disclaimer.
===========
(7) BRIGHTENING COMET C/20001 A2 (LINEAR)
From Space Weather News for May 12, 2001
http://www.spaceweather.com
BRIGHTENING COMET: Comet C/2001 A2 (LINEAR), which split into two
pieces
last month, suddenly brightened to visual magnitude ~5.3 on May
10th and
11th. The comet's appearance is changing as volatile ices in the
fragmenting
nucleus are exposed to solar radiation. No one knows how much
brighter Comet
LINEAR A2 might become between now and May 24th, when it will
experience a
0.78 AU close encounter with the Sun. Southern hemisphere sky
watchers using
binoculars can monitor the crumbling comet after local sunset
near the feet
of Orion. See: [3D orbit][ephemeris][May 13th finder chart]
==========
(8) ALIEN VISITORS
From New Scientist, 11 May 2001
http://www.newscientist.co.uk/dailynews/news.jsp?id=ns9999725
Live bacteria are cultured from a meteorite, but are they just
little
Earthlings?
Live bacteria have been found inside a meteorite in a Naples
museum,
according to two researchers at the University of Naples - and
they claim
the bacteria are not from Earth.
If these really were the first alien bugs, it could dramatically
settle the
controversial theory that life colonised Earth from space. But
British
geologists, who found local bacteria living inside a meteorite in
Antarctica
last year, caution that the Italians may simply have observed
little
Earthlings.
Bruno D'Argenio, a geologist, and Giuseppe Geraci, a molecular
biologist,
say they cultured bacteria from a meteorite kept at the
mineralogical museum
in Naples. The bacteria were wedged inside the crystal structure
of
minerals, but were resurrected when a sample of the rock was
placed in a
culture medium. They formed colonies and were susceptible to
antibiotics.
The team put out a press release with these observations this
week, but have
not yet reported their methods to colleagues. D'Argenio will
present them to
a meeting on extraterrestrial biology in Frascati, Italy later in
May.
Extreme temperatures
The proof that the bacteria were not terrestrial, the team
claims, was that
they survived when the sample was sterilised at 950 °C and
washed with
alcohol. Bacteria that arrive from space should survive high
heat, they
argue, while the alcohol would eliminate surface-dwelling Earth
microbes.
But David Wynn-Williams of the British Antarctic Survey says
Earth bacteria
could easily have invaded the structure of the rock as it lay in
the museum,
to depths that were not affected by the heat or alcohol.
He and colleagues found actinomycete bacteria inside the crystals
of a
Martian meteorite last year, which looked exactly like Antarctic
soil
bacteria, and grew on encountering moisture.
Gene test
The Italian team also claims their bacteria's DNA is unlike any
on Earth.
"But without the experimental details, we really cannot
say," says Luigi
Colangelli of the Capodimonte Observatory in Naples.
"I believe we will find evidence of life elsewhere,"
says Wynn-Williams.
"But it almost requires keeping a meteorite sterile from the
moment it
lands."
This difficult task could get harder. Evidence has recently
emerged of the
escalating black market trade in stolen meteorites.
Copyright 2001, New Scientist
==========
(9) NEW RADIO TELESCOPE AMKES FIRST OBSERVATIONS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
National Radio Astronomy Observatory
520 Edgemont Road
Charlottesville, VA 22903
http://www.nrao.edu
Contact:
Dave Finley, Public Information Officer
(505) 835-7302, dfinley@nrao.edu
May 10, 2001
New Radio Telescope Makes First Scientific Observations
The world's two largest radio telescopes have combined to make
detailed
radar images of the cloud-shrouded surface of Venus and of a tiny
asteroid
that passed near the Earth. The images mark the first scientific
contributions from the National Science Foundation's (NSF) new
Robert C.
Byrd Green Bank Telescope in West Virginia, which worked with the
NSF's
recently-upgraded Arecibo telescope in Puerto Rico. The project
used the
radar transmitter on the Arecibo telescope and the huge
collecting areas of
both telescopes to receive the echoes.
"These images are the first of many scientific contributions
to come from
the Robert C. Byrd Green Bank Telescope, and a great way for it
to begin its
scientific career," said Paul Vanden Bout, director of the
National Radio
Astronomy Observatory (NRAO). "Our congratulations go to the
scientists involved in this project as well as to the
hard-working staffs at
Green Bank and Arecibo who made this accomplishment
possible," Vanden Bout
added.
To the eye, Venus hides behind a veil of brilliant white clouds,
but these
clouds can be penetrated by radar waves, revealing the planet's
surface. The
combination of the Green Bank Telescope (GBT), the world's
largest
fully-steerable radio telescope, and the Arecibo telescope, the
world's most
powerful radar, makes an unmatched tool for studying Venus and
other
solar-system bodies.
"Having a really big telescope like the new Green Bank
Telescope to receive
the radar echoes from small asteroids that are really close to
the Earth and
from very distant objects like Titan, the large moon of Saturn,
will be a
real boon to radar studies of the solar system." said
Cornell University
professor Donald Campbell, leader of the research team.
Ten years ago, the radar system on NASA's Magellan spacecraft
probed though
the clouds of Venus to reveal in amazing detail the surface of
the Earth's
twin planet. These new studies using the GBT and Arecibo, the
first since
Magellan to cover large areas of the planet's surface, will
provide images
showing surface features as small as about 1 km (3,000 ft), only
three times
the size of the Arecibo telescope itself.
Venus may be a geologically active planet similar to the Earth,
and the new
images will be used to look for changes on Venus due to volcanic
activity,
landslides and other processes that may have modified the surface
since the
Magellan mission. The radar echoes received by both telescopes
also can be
combined to form a radar interferometer capable of measuring
altitudes over
some of the planet's mountainous regions with considerably better
detail
than was achieved by Magellan.
These were the first scheduled observations with the new Robert
C. Byrd
Green Bank Telescope, demonstrating its capabilities for
solar-system
studies. In addition to the observations of Venus, a tiny 150m
(500 ft)
asteroid, 2001 EC16, was imaged with the two telescopes working
as a
combined radar system on March 26 when the asteroid was only 8
times the
distance of the Moon from the Earth. The image could show details
on the
asteroid's surface only 15 meters (50 ft) in size and shows EC16
to be an
irregularly shaped object rotating about once every 200 hrs, one
of the
slowest rotation rates so far measured for these objects. It took
about 20
seconds for the radar signal to go to EC16 and back, compared
with the
almost 5 minutes needed to go to Venus and back. EC16 was
discovered by the
NEAT asteroid survey on March 15, 11 days prior to the radar
observations.
Very large numbers of these near-Earth asteroids are being
discovered and
the combined Arecibo-GBT radar system will be needed to properly
study a
significant number of them.
The observing team led by Campbell also included Jean-Luc Margot
of Caltech,
Lynn Carter of Cornell, and Bruce Campbell of the Smithsonian
Institution.
The 100-meter (330 feet) Robert C. Byrd Green Bank Telescope was
dedicated
in August 2000 and now is being prepared for routine scientific
operation.
It is operated by the National Radio Astronomy Observatory,
headquartered in
Charlottesville, Virginia. It is the largest fully-steerable
telescope in
the world. It is a highly advanced telescope with a mechanized
reflecting
surface and a laser measurement system for continuous adjustments
to its
structure.
The 305-meter (1,000 feet) Arecibo telescope recently has
completed a major
upgrade funded by the NSF and NASA to improve its observing
capabilities,
including a more powerful radar transmitter for planetary
studies. It is
operated by the National Astronomy and Ionosphere Center (NAIC)
headquartered at Cornell University. Its reflector is fixed to
the ground,
and is the largest telescope of any type in the world. The radar
capability
of Arecibo, combined with the large reflectors of Arecibo and
Green Bank,
make for a uniquely powerful radar imaging capability. Both
observatories
are facilities of the National Science Foundation. The NRAO is
operated for
the NSF by Associated Universities, Inc., under a cooperative
agreement.
NAIC is operated by Cornell University, also under a cooperative
agreement
with the NSF.
Images to Accompany This Story
* Arecibo-GBT radar image of Venus, showing detail as small as 5
kilometers.
Image courtesy of Campbell et al., NRAO, NAIC.
http://www.aoc.nrao.edu/pr/venus.jpg
(920KB)
* Arecibo-GBT radar image of Maxwell Montes, a Venusian mountain
taller than
Mount Everest. Image courtesy of Campbell et al., NRAO,
NAIC.
http://www.aoc.nrao.edu/pr/maxwell.jpg
(275KB)
* Arecibo-GBT radar image of asteroid 2001 EC16 , showing detail
as small as
15 meters and clearly showing the irregular shape of the
asteroid. Image
courtesy of Campbell et al., NRAO, NAIC.
http://www.aoc.nrao.edu/pr/ec16.0-2.gif
(21KB)
* Images of the Robert C. Byrd Green Bank Telescope
http://www.nrao.edu/news/images.shtml
============================
* LETTERS TO THE MODERATOR *
============================
(10) RE: THE END IS SHY
From Ian Lyon <ilyon@fs1.ge.man.ac.uk>
Dear Benny,
A minor point about the report by Philip Ball (Nature, 9 May
2001) 'The End
is Shy' [CCNet, 11 May 2001):
"Rybicki and Denis calculate the effects of these drag
forces on the
orbits of the planets. In particular, they consider tidal forces.
The Moon
loses a little energy as it sloshes the Earth's oceans back and
forth, and this causes a tiny, constant decrease in the Moon's
orbit. The
same would happen to the Earth if the Sun's outer envelope were
to come
close enough."
In fact the Earth is slowing its rotation due to tidal friction
and from the
conservation of angular momentum, the moon is actually getting
further away
from the Earth, not closer.
Regards
Ian Lyon
ps please keep up the good work, CCNet is an informative read!
Dr Ian Lyon
Senior Lecturer in Isotope Geochemistry
Department of Earth Sciences
University of Manchester
Manchester
M13 9PL
UK
Tel: 0161 275 3842 (or 3942)
Fax: 0161 275 3947
Ian.Lyon@man.ac.uk
=========
(11) MARS TROJANS
From Duncan Steel <D.I.Steel@salford.ac.uk>
From CCNet (11/5/01):
Melita MD, Brunini A: A possible long-lived asteroid population
at
the equilateral Lagrangian points of Saturn MONTHLY NOTICES OF
THE
ROYAL ASTRONOMICAL SOCIETY 322 (2): L17-L21 APR 1 2001
The Lagrangian equilateral points of a planetary orbit are points
of
equilibrium that trail at 60 degrees, ahead (L4) or behind (L5),
the
trajectory of a planet. Jupiter is the only major planet in our
Solar
system harbouring a known population of asteroids at those
locations.
This is not true. There are four known Mars-Trojan asteroids, all
at L5. The
first of them was discovered in 1990 and deserves its name:
(5261) Eureka.
For more information see the appropriate page at the IAU Minor
Planet Center
web site (which, I might add, carries all sorts of useful
information for interested parties):
http://cfa-www.harvard.edu/iau/lists/MarsTrojans.html
Duncan Steel
=========
(12) SPECIES SURVIVAL
From Leon Neihouse <neihouse@gwi.net>
Dear Benny,
I question whether the viewpoint expressed in the article in the
last post
entitled "INSURANCE PLANS FOR HUMANITY'S SURVIVAL" can
withstand an
objective analysis.
I strongly support the call made by J. Richard Gott III to build
a
self-supporting colony in space. However, I seriously question
whether it
should be tied to the alarmist position that such a project is
necessary to
ensure the human race can survive a collision with a gargantuan
asteroid or
comet.
The preparations we have already made to kill each other will,
paradoxically, ensure we can survive such a conjectured impact.
As a minimum, several months will be available to prepare for a
collision
with a Hale-Bopp type of object. For just one example of many
possible
courses of action, the United States might "bury"
equipment and components
necessary for self-sufficient living in several unmanned sites
well
protected to survive the after effects of an impact. About ten
thousand of
the "best and brightest" could then board the Navy's
nuclear powered
submarine fleet and transit to that global sea location that
would be the
least effected by the blast. This contingent could easily remain
submerged
for up to three months, at which time all short-term effects
would have
played their course. The submarines would then surface and the
occupants
would establish a new foothold for the human race from the
locations
previously prepared for this purpose.
I am sure many other survival scenarios can be developed using
only Earth
based equipment and components. For example, I am of the opinion
that
precautions almost certainly put in place by national governments
such as
the USA and Russia to survive a full-scale nuclear exchange will
collaterally permit the human race to survive an impact by a
gargantuan
asteroid or comet.
While I support space development, I believe it should be
promoted on its
own merits.
Best regards,
Leon Neihouse
http://www.alphaspaceproducts.com
============
(13) INTERNATIONAL EMERGENCY CONDITION
From Andy Smith <astrosafe@yahoo.com>
Hello Benny and CCNet,
We think the time has come to collectively recognize that an
international
emergency exists and to join, togeather, in all of our efforts.
Our initial
delegation draft is provided, herewith:
OUR DECLARATION
We recognize that an international emergency condition exists and
that there
is a clear and present danger of asteroid/comet impact.....which
could come
upon us at any time. We further recognize that the entire human
race (and
all life on our planet) is at risk.
We further recognize that there are more than 100,000 potentially
dangerous
objects overhead (Near-Earth Objects or NEO), which are larger
than the
objects that made the one-mile wide Barringer Crater (Arizona,
USA) and
destroyed the forest (Tuguska River, Siberia) in Russia, in 1908;
that there
is a near-miss of our orbit, by one of these objects...about
every half-hour
and that there is an impact on our planet, every Century.
Further, we recognize that the human race has the technology and
the
equipment necessary to identify and track most of these dangerous
objects
and to prevent most impacts. In spite of this capability, our
progress
toward the goal of adequate emergency preparedness and the level
of support,
for that progress, is much too little (in light of the clear
danger).
In addition, we are aware that there are a number of impressive
programs
underway, to help identify the 100,000 NEO and that the time
which will be
required to identify the threat population, at the present
discovery rate,
is likely to be about 300 years. We also recognize that it may be
possible
to reduce this discovery time to about a decade, if we build one
large
state-of-the-art survey telescope (8 meter/900 megapixel) and use
that
facility exclusively for the stated purpose...in coopertion with
the
existing asteroid survey systems and teams. We consider this
project to have
the highest priority and encourage all CCNet participants to join
us in
supporting this project and priority. The future of the human
race could
well hinge upon this action.
The second priority, for us, is to encourage and support the
development of
contingency plans for a rapid world defensive response, to any
asteroid/comet emergency. We also favor the development of plans,
in all
countries, for civil emergency preparedness and we assign the
highest
priority, for such preparedness, to the coastal cities (because
of the
tsunami danger).
We pledge our time and resources to this cause and we call upon
all
countries and people to join us, in an open and coordinated
effort. This is
our first encounter with a credible extra-terrestrial physical
threat. It is
the greatest danger we know and, fortunately, it is the one
natural danger
we can prevent.
CONFERENCES CAN HELP
Our Asteroid/Comet Workshop (ACW), at the International Space
Development
Conference, will be held in the spirit of this declaration and
the
declarations by the American Institute of Aeronautics and
Astronautics (AIAA
in 1990 and 1995); the National Space Society (NSS)...
before the U.S.
Congress, in 1998; the declarations associated with the recent
hearings,
before the House of Commons (U.K.)and other declations and
studies,
conducted in recent times.
In addition, we request that the participants of the ASTEROIDS
2001
conference, which will be held in Italy, in June, recognize this
emergency
condition and support the development of the vital large asteroid
telescope.
We also ask that the INTERNATIONAL WORKSHOP, planned in Japan, in
October
(see CCNet4/18/01), and intended to promote cooperation (in this
vital
hunt), join us in this declaration and discuss a maximum World
discovery and
tracking effort, using the large terrestrial telescope, the
existing
asteroid telescopes and an orbiting system.
Finally, because of the gravity of the danger, we call upon all
of the large
survey telescopes, in the World, to aid in this vital hunt and to
make
significant contributions to the world NEO data-base (MPC).
International Planetary Protection Alliance (IPPA)/
Andy Smith
-------------------------------------------------------------------
THE CAMBRIDGE-CONFERENCE NETWORK (CCNet)
--------------------------------------------------------------------
The CCNet is a scholarly electronic network. To
subscribe/unsubscribe,
please contact the moderator Benny J Peiser <b.j.peiser@livjm.ac.uk>.
Information circulated on this network is for scholarly and
educational use
only. The attached information may not be copied or reproduced
for
any other purposes without prior permission of the copyright
holders. The
fully indexed archive of the CCNet, from February 1997 on, can be
found at
http://abob.libs.uga.edu/bobk/cccmenu.html
DISCLAIMER: The opinions, beliefs and viewpoints expressed in the
articles
and texts and in other CCNet contributions do not
necessarily reflect the
opinions, beliefs and viewpoints of the moderator of this
network.
