CCNet 6/2002 - 9 January 2002


"Australia had an asteroid-spotting program partly funded by the
Federal Government, but this was stopped by the Howard Government in
1996. It would cost only several million dollars a year to fund the
search, Professor Davies said. The US and Britain were keeping watch, but
in the southern hemisphere, Australia was letting the world down, he said. A
spokeswoman for Science Minister Peter McGauran said he would investigate
funding a program, and Dr Schmidt said he hoped to soon start his own
asteroid watch."
--The Age, 9 January 2002

"While asteroid YB5 is now safely past Earth, Prof. Brown and other
scientists say the fly- by is a reminder of how vulnerable the planet is to
the huge wayward rocks that periodically come flying out of the asteroid
belt between Mars and Jupiter.... astronomers have been improving efforts
to track potentially hazardous asteroids. But a key component of the
international effort -- Mr. Balam's asteroid-tracking program in Victoria --
was shut down three weeks ago because of a lack of funding and support.
"We just couldn't keep it up," says Mr. Balam, noting how the program
operated on a shoestring budget for years."
--Margaret Munro and Joe Brean, National Post, 8 January

"Had it been on a collision course, it would have created "one of
the worst disasters in human history," said Steven Pravdo, the NEAT project
manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "What
could we have done about it? The answer is not much," Pravdo said."
--Associated Press, 8 January 2002

    The Age, 9 January 2002

    National Post Online, 8 January 2002

    FLORIDA TODAY, 8 January 2002

    The Seattle Times, 9 January 2002

    Andrew Yee <>

    Andrew Yee <>

    Andrew Yee <>

    Paal Brekke <>

    Lew Gramer <>

     Drake A. Mitchell <>

     Jens Kieffer-Olsen <>

     Colin Keay <>

     Space Daily, 8 January 2002


>From The Age, 9 January 2002


An asteroid big enough to obliterate a major country missed Earth by a
stellar hair's breadth on Monday night, prompting calls from scientists for
Australia to join the search for rogue space rocks.

Had it struck, the asteroid, measuring up to half a kilometre across in
places, would have created the force of hundreds of atomic bombs. Instead,
it glided harmlessly past less than twice the distance from the moon to
Earth, coming within 600,000 kilometres at 6.37pm on Monday.

In astronomical terms it grazed the Earth's surface, said Brian Schmidt,
Australian National University's expert on asteroids. Had it hit
metropolitan Melbourne it would have created total devastation for 150
kilometres, and taken out most of Sydney as well.

"Such an object would literally wipe out a medium-sized country and lead to
a global economic meltdown," said Benny Peiser, an asteroid expert from John
Moores University, in England.

The asteroid, named 2001 YB5, was spotted early last month by a Near-Earth
Asteroid Tracking (NEAT) survey telescope on Mount Palomar, California.

But asteroids larger than 2001 YB5 frequently passed near Earth without
being noticed, said Australian physicist Paul Davies.

An asteroid one kilometre across could destroy half the world's population,
creating a cataclysmic shockwave and tsunamis, followed by a hurricane and
an earthquake that would topple buildings around the globe.

"You're talking about something pretty colossal," he said.

Apocalyptic asteroids such as the massive hunk of rock 10 kilometres wide
that wiped out the dinosaurs 65 million years ago, are rare occurences.

But impacts such as the 60-metre asteroid that hit Siberia in 1908, with a
force 600 times that of the Hiroshima bomb, happened once or twice every
century, Professor Davies said.

There would be virtually no warning, but with more money worldwide for the
NEAT program, scientists could spot a rogue asteroid well in advance, giving
military specialists enough time to knock it off its path with controlled
nuclear missile strikes.

Australia had an asteroid-spotting program partly funded by the Federal
Government, but this was stopped by the Howard Government in 1996.

It would cost only several million dollars a year to fund the search,
Professor Davies said. The US and Britain were keeping watch, but in the
southern hemisphere, Australia was letting the world down, he said.

A spokeswoman for Science Minister Peter McGauran said he would investigate
funding a program, and Dr Schmidt said he hoped to soon start his own
asteroid watch.

Copyright 2002, The Age


>From National Post Online, 8 January 2002

Asteroid misses Earth by a cosmic whisker. Devastation averted: B.C. program
that tracks space rocks just lost funding

Margaret Munro and Joe Brean
National Post, with files from Agence France-Presse
Between 20,000 and 50,000 years ago, a small asteroid about 24 metres in
diameter struck the Earth and formed this crater in Arizona that measures
1.2 km in diameter. The discovery of fragments of the Canyon Diablo
meteorite helped prove the feature was in fact an impact crater.
An asteroid packing the power of hundreds of nuclear bombs and capable of
wiping out a major country hurtled past Earth early yesterday in what
astronomers say was a close call.

The giant space rock, known as 2001 YB5 and believed to be between 220 and
490 metres across, was only twice as far away as the moon as it sped by
Earth at about 1:30 a.m. Eastern time.

Experts said the distance -- about 600,000 kilometres -- is a whisker in
cosmic terms, and the rock would have caused global chaos had it smacked the

"It could have vaporized the core of a city like Toronto, leaving a crater
two to three kilometres across and creating a huge fireball and shock wave
that would have knocked you off your feet in Vancouver," says University of
Victoria astronomer Dave Balam, who has been tracking asteroids for 25

He and other astronomers say the dust cloud kicked up by such an impact
could have exacted a huge global toll, triggering crop failures and climate
changes that could have been felt for years. "Such an object could literally
wipe out a medium-sized country if it impacted and lead to a global economic
meltdown," said British asteroid expert Benny Peiser, at Liverpool John
Moores University.

Even worse, the asteroid could have crashed into the ocean, unleashing
devastating tsunamis.

Had YB5 splashed down in the Pacific, low-lying coastal cities and
communities from Canada to Australia could have been hit, causing millions
of deaths, says Professor Peter Brown at the University of Western Ontario,
who studies such space menaces.

While asteroid YB5 is now safely past Earth, Prof. Brown and other
scientists say the fly-by is a reminder of how vulnerable the planet is to
the huge wayward rocks that periodically come flying out of the asteroid
belt between Mars and Jupiter.

Thousands of asteroids the size of YB5 are believed to be flying though
space but there is little information on their orbits, Prof. Brown said. As
in the case of YB5, they just suddenly appear on the radar screen.

YB5 was only spotted heading toward Earth on Boxing Day by a Near-Earth
Asteroid Tracking survey telescope on Mount Palomar in California. NASA
designated the asteroid "potentially hazardous," a designation that applies
to any object larger than 150 metres that will come within 7.5 million
kilometres of our planet, says Don Yeomans, manager of NASA's Near Earth
Object Program office.

By studying the light reflecting off the rock, scientists estimate it is
travelling at 30.6 kilometres a second. If it hit, Mr. Yeomans says, the
impact would have weighed in at 6,000 megatonnes.

Astronomers stress that at no point did they think the asteroid would crash
into Earth -- a good thing, as there was too little time to have done
anything to deflect or destroy the asteroid.

"It is a reminder of what is going to happen unless we track them more
efficiently than we do and make better preparations to defend our planet,"
Dr. Peiser said.

U.S. and British astronomers have been improving efforts to track
potentially hazardous asteroids. But a key component of the international
effort -- Mr. Balam's asteroid-tracking program in Victoria -- was shut down
three weeks ago because of a lack of funding and support. "We just couldn't
keep it up," says Mr. Balam, noting how the program operated on a shoestring
budget for years.

The National Research Council contributed time on its telescope in Victoria
more than 100 nights a year, and a U.S. foundation had been covering Mr.
Balam's salary as he tracked small asteroids and fed the information to the
international asteroid tracking community. The U.S. funding was cut last
year and no Canadian money could be found to replace it, despite an
endorsement from the Canadian Space Agency's meteorites and impacts advisory
committee, which wanted the program to survive.

"It's really an incredible loss to Canadian planetary science, and a big
loss to the international community," says Prof. Brown, who sits on the
committee. He says Mr. Balam is one of the world's premier asteroid

"People like Dave are a national treasure," said Prof. Alan Hildebrand, at
the University of Calgary, who chairs the CSA committee.

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.

NASA's main focus is on identifying asteroids between one and 10 kilometres
across. The number of these is estimated at 700, plus or minus 230. That
leaves the vast majority of space objects, which are under one kilometre,
still to be detected and tracked.

An asteroid believed to be about 10 kilometres across smashed into Mexico's
Yucatan Peninsula 65 million years ago, killing the dinosaurs and much other
life on Earth. That impact is believed to have triggered a firestorm and a
dust cloud that obscured sunlight around the planet for decades.

The space rock that flew by yesterday was "not in the same game," said Prof.
Hildebrand, who helped prove a giant asteroid killed off the dinosaurs.

But Prof. Hildebrand says smaller rocks -- like 2001 YB5 -- pose a real
threat and should be tracked, since it might be possible to divert those
bound for Earth.

In 1908, an asteroid believed to have been about 60 metres across exploded
over Siberia with the force of 600 times the Hiroshima bomb, reducing a
40-kilometre wide patch of forest to matchwood.

David Jewitt, an astronomer at the University of Hawaii at Honolulu, has
estimated there is a 1% chance the Earth will be struck by a 300-metre
asteroid sometime this century.

"Such an impact would deliver a withering 1,000-megatonne explosion and
cause perhaps 100,000 deaths," he said, adding that in a densely populated
area, such as the U.S. eastern seaboard or Western Europe, the fatalities
could rise into tens of millions.

Copyright © 2002 National Post Online


>From FLORIDA TODAY, 8 January 2002!NEWSROOM/localstoryA8059A.htm

By Steven Siceloff

CAPE CANAVERAL -- An asteroid the size of a city block passed Earth on
Monday, reminding astronomers of the risk posed by thousands of objects that
could slam into the planet with little warning.

The asteroid, named 2001 YB5, approached less than 520,000 miles from the
Earth -- about twice the distance from the Earth to the moon. That is a
close call to astronomers who discovered the object only two weeks ago.

Longer than three football fields, the asteroid would've doomed any state it
landed on or drowned coastal cities in a tidal wave in the event of an ocean
impact, experts said.

"It would be well beyond all of the atomic weapons in the U.S. and Russian
arsenals," said Don Yeomans, project manager of NASA's Near Earth Objects
program. "If it hit in the ocean near a continent, all the cities on that
coast would be destroyed."

An asteroid the size of YB5 does not carry enough energy to wipe out life
worldwide, said David Morrison, who analyzes asteroid and comet impacts at
NASA's Ames Research Center in California. But it would cause problems.

"The impact of something that big would dig an impact crater the size of
Melbourne and do damage for several states around," he said. "If I'm in San
Francisco, I would not be affected if it hit in Florida." [If a 300m
asteroid were to hit Florida, God forbid, Dave may not be affected
physically - but he and all North Americans would be affected in a
catastrophic way - politically and socio-economically: Such a massive
disaster that would destroy most of one of the most important and densely
populated states in the US, would almost certainly lead to an immediate
collapse of the North American and global economies; BJP]

Asteroids of that size hit Earth about once every 200 to 300 years, Morrison
said. [I'm sure Dave was misquoted here; asteroids that size collide with
Earth every 5000-6000 years or so, BJP.]

The asteroid that passed by Monday travels 19 miles a second, offering
little time to move it out of the way -- even if that were possible -- if it
threatened Earth.

"By the time you found it, you wouldn't be able to do anything," said Bob
Farqua of Johns Hopkins University Applied Physics Laboratory. Farqua led
the Near Earth Asteroid Rendezvous program that landed a satellite on an
asteroid last year.

Farqua said officials may try to use missiles against an approaching rock
out of desperation, but said it could be a waste since scientists know so
little about the makeup of the objects.

"There's nothing you could have done in two weeks," Morrison said. "Nor even
two years." [I wouldn't be that fatalistic with two years warning time,
although I admit that chances would be slim. But if the international
community would put all its technological and financial resources into a
rescue mission, I wouldn't rule out that a realistic deflection mission
could be launched even within a two-year time limt; BJP].

Morrison said it would take years if not a decade or more to assemble a
rocket and components needed to nudge a doomsday asteroid away from Earth.

"This is the one natural disaster we could do something about," he said. "I
doubt we'll ever be able to invent a machine that can stop an earthquake."

Objects larger than a mile across are estimated to crash into Earth about
once every 100 million years, according to Morrison. [Again, I cannot
believe that Dave Morrison is quoted corrcetly here. A 1km-sized asteroid
hits the Earth on average every 1 million years, BJP]

There are perhaps 100,000 objects similar to YB5, Yeomans said. Astronomers
have found about 1,000 of them so far. More than 350 of the objects have
been labeled potential threats to Earth.

NASA has given the near earth object program the goal of finding 90 percent
of objects two-thirds of a mile or larger that fly near Earth by 2008.

While the odds of substantial asteroids hitting the Earth are small, the
consequences are too severe to risk doing nothing, Yeomans said.

"The key is to find these things decades in advance, then you can track them
and predict when they might hit Earth," Yeomans said. "This is Mother
Nature's way of giving us a wake-up call."

While some are concerned the asteroid was found less than a month before its
closest swing by Earth, Morrison took it as a good sign that astronomers are
getting the equipment they need to find the asteroids.

"Something that big goes by the planet that close every few months, we just
happened to find this one," he said.

NASA and its staff of a few dozen astronomers spend $3.5 million a year
scanning the sky for asteroids in Earth's neighborhood. They use Air Force
telescopes in Hawaii, California and several other locations for their

Because the objects are only easily seen as they get close to Earth,
Morrison said astronomers will spot them as they cross the planet's orbit
decades in advance of impact, or they will be discovered too late.

"We would either have decades of warning, or we would see the flash of light
in the sky and feel the Earth start to shake." [This untenable situation is
largely due to the fact that NEO searches are currently limit to small and
terrestrial telescopes. Once satellites will get involved in NEO searches,
our chances for detecting Virtual Impactors much earlier will increase
significantly, BJP].

Most of what is understood about asteroid impacts comes from fragments found
in the snow or dirt, and from the study of two known collisions: one in
Siberia in 1908, and the impact of 65 million years ago that permanently
changed the Earth.

Researchers had developed several kinds of sensors in the early 20th century
that measured the concussion of an asteroid that smashed a Siberian forest
in 1908. It was about one-third the size of the rock that passed Earth on
Monday. The rock exploded in the air, but seismic recorders picked up the
shock wave about 600 miles away. The explosion threw people in the air more
than 40 miles away, leaving them unconscious.

A much larger asteroid is thought to have slammed into the planet 65 million
years ago, creating the Yucatan Peninsula and raising a dust cloud so thick
it blocked out the sun and changed the Earth's climate. Researchers say the
side effects killed the dinosaurs.

Copyright © 2001 FLORIDA TODAY


>From The Seattle Times, 9 January 2002

By The Associated Press

LOS ANGELES - An asteroid large enough to wipe out France hurtled past Earth
at a distance of a half-million miles just days after scientists spotted it.

The asteroid, dubbed 2001 YB5, came within 520,000 miles of Earth on Monday,
approximately twice the distance of the moon.

Dozens of asteroids pass close by Earth each year, although 2001 YB5 was
closer than most. On Friday, for instance, an asteroid known as 2001 UU92
will pass with 11 million miles of Earth.

Asteroid 2001 YB5, estimated to be 1,000 feet across, was traveling about
68,000 mph relative to the Earth when it zipped past.

"It's a fairly substantial rock. If it had hit us at that sort of speed, you
would be taking out a medium-size country, France, I suppose, or Texas, or
something of that order," said Jay Tate, director of the Spaceguard Centre
in Wales.

Astronomers with the National Aeronautics and Space Administration's
Near-Earth Asteroid Tracking (NEAT) program discovered 2001 YB5 on Dec. 26.
Soon after, astronomers calculated the asteroid's orbit and determined there
was no danger it would strike Earth.

Had it been on a collision course, it would have created "one of the worst
disasters in human history," said Steven Pravdo, the NEAT project manager at
NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"What could we have done about it? The answer is not much," Pravdo said.

Copyright © 2002 The Seattle Times Company


>From CBS News, 8 January 2002,1597,323590-412,00.shtml

Zemi minul asteroid, který hrozil srázkou

Un asteroide "sfiora" la Terra Scoperto tardi dagli astronomi

Pozor na asteroid

Un peligroso asteroide rozó la Tierra

Large Asteroid Passes Close to Earth

Un nuevo asteroide se ha acercado peligrosamente a la Tierra, a menos del
doble de distancia que la Luna

Asteroid misses Earth by 4 hours

Deadly Asteroid Narrowly Misses Earth


>From Andrew Yee <>

Office of Public Relations
University of Missouri-Rolla
Rolla, Missouri

Contact: Andrew Careaga
Phone: 573-341-4328

January 8, 2002


ROLLA, Mo. -- For years, scientists have assumed that the sun is an enormous
mass of hydrogen. But in a paper to be presented Thursday, Jan. 10, at the
American Astronomical Society's meeting in Washington, D.C., Dr. Oliver
Manuel says iron, not hydrogen, is the sun's most abundant

Manuel, a professor of nuclear chemistry at the University of
Missouri-Rolla, claims that hydrogen fusion creates some of the sun's heat,
as hydrogen -- the lightest of all elements -- moves to the sun's surface.
But most of the heat comes from the core of an exploded supernova that
continues to generate energy within the iron-rich interior of the sun,
Manuel says.

"We think that the solar system came from a single star, and the sun formed
on a collapsed supernova core," Manuel says. "The inner planets are made
mostly of matter produced in the inner part of that star, and the outer
planets of material form the outer layers of that star."

Manuel will present his the evidence for his assertion in his paper, "The
Origin of the Solar System with an Iron-rich Sun," at 10 a.m. Thursday, Jan.
10, at the AAS' 199th annual meeting at the Hilton Washington and Towers in
Washington, D.C. In addition, Cynthia Bolon, a UMR graduate student in
chemistry who has studied with Manuel, will present related research in her
paper, "Repulsion and Attraction between Nucleons: Sources of Energy for an
Iron-rich Sun and for First Generation Stars," following Manuel's presentation.

Manuel says the solar system was born catastrophically out of a supernova --
a theory that goes against the widely-held belief among astrophysicists that
the sun and planets were formed 4.5 billion years ago in a relatively
ambiguous cloud of interstellar dust.

Iron and the heavy element known as xenon are at the center of Manuel's
efforts to change the way people think about the solar system's origins.

Manuel believes a supernova rocked our area of the Milky Way galaxy some
five billion years ago, giving birth to all the heavenly bodies that
populate the solar system. Analyses of meteorites reveal that all primordial
helium is accompanied by "strange xenon," he says, adding that both helium
and strange xenon came from the outer layer of the supernova that created
the solar system. Helium and strange xenon are also seen together in

Manuel has spent the better part of his 40-year scientific career trying to
convince others of his hypothesis. Back in 1975, Manuel and another UMR
researcher, Dr. Dwarka Das Sabu, first proposed that the solar system formed
from the debris of a spinning star that exploded as a supernova. They based
their claim on studies of meteorites and moon samples which showed traces of
strange xenon.

Data from NASA's Galileo probe of Jupiter's helium-rich atmosphere in 1996
reveals traces of strange xenon gases -- solid evidence against the
conventional model of the solar system's creation, Manuel says.

Manuel first began to develop the iron-rich sun theory in 1972. That year,
Manual and his colleagues reported in the British journal Nature that the
xenon found in primitive meteorites was a mixture of strange and normal
xenon (Nature 240, 99-101).

The strange xenon is enriched in isotopes that are made when a supernova
explodes, the researchers reported, and could not be produced within

Three years later, Manuel and Sabu found that all of the primordial helium
in meteorites is trapped in the same sites that trapped strange xenon. Based
on these findings, they concluded that the solar system formed directly from
the debris of a single supernova, and the sun formed on the supernova's
collapsed core. Giant planets like Jupiter grew from material in the outer
part of the supernova, while Earth and the inner planets formed out of
material form the supernova's interior.

This is why the outer planets consist mostly of hydrogen, helium and other
light elements, and the inner planets are made of heavier elements like
iron, sulfur and silicon, Manuel says.

Strange xenon came from the helium-rich outer layers of the supernova, while
normal xenon came from its interior. There was no helium in the interior
because nuclear fusion reactions there changed the helium into the heavier
elements, Manuel says.

More information is available on the Web at

Information about the American Astronomical Society is available on the Web


>From Andrew Yee <>

Press & Communications Office
University of Sussex
Falmer, Brighton, U.K.

08 January 2002

Good news: how the Earth will survive when the Sun becomes a supergiant

The astronomy textbooks will have to be rewritten, say astrophysicists at
the University of Sussex who have re-examined standard calculations about
solar evolution and the distant future of the Earth.

The textbooks tell us that one day the Sun will burn up its nuclear fuel and
expand to an enormous size, finally engulfing its inner planets including
Earth. However, using the latest data based on real stars, the University of
Sussex researchers suggest a (slightly) less
catastrophic future for our planet.

As their hydrogen fuel runs out at the end of their 'lives', stars like the
Sun expand to become a red supergiant of several hundred times their initial
diameter. Most astronomers expect the solar red supergiant to swallow
Mercury, Venus and then Earth in about 7.5 billion years' time, when it has
expanded beyond the orbit of our planet.

But Earth may survive after all, say the Sussex astronomers, if an important
extra detail is considered: the ongoing loss of mass and weakening gravity
while a star is a red supergiant.

Dr Robert Smith, Reader in Astronomy, explains the significance of this
effect: "Taking this into account, the orbit of the Earth would increase
beyond the Sun's outer atmosphere by a small but crucial margin at all
phases of the Sun's evolution -- allowing our planet to continue."

The new calculations are published in the current issue of Astronomy &
Geophysics. They were made by Dr Smith together with Dr Klaus-Peter Schröder
from the University's Astronomy Centre and Kevin Apps, the famous student
stargazer who co-discovered 10 planets while still an undergraduate at

Although the Earth may survive, long before then its surface will have
become too hot to sustain human life. But the good news from the team of
researchers is that it will be 5.7 billion years before our planet becomes a
no-go zone for life -- about 200 million years later than
previously thought.

So, ask the Sussex astronomers, is there anywhere in the solar system that
would be safe, or does our survival depend on finding another star system?
Is it possible to hop outwards from one planet or satellite to the next,
always keeping ahead of the Sun? There are periods, they calculate, when we
could in principle survive on one of the outer planets such as Mars, but
there will be long gaps when none of them is habitable.

Dr Smith concludes: "We had better get used to the idea that we shall need
to build our own survival capsules -- the planets are simply too far apart
for planet-hopping to be a viable solution. Perhaps this is the ultimate
justification for developing an International Space Station."

Notes for editors

For further information, please contact:

Alison Field or Peter Simmons, University of Sussex
Tel. 01273 678888
Fax 01273 877456
email or


>From Andrew Yee <>

Office of News and Information
Johns Hopkins University
3003 N. Charles Street, Suite 100
Baltimore, Maryland 21218-3843
Phone: (410) 516-7160   Fax (410) 516-5251

Michael Purdy, (410) 516-7906,


Ancient Supernova May Have Triggered Eco-Catastrophe

An exploding star may have destroyed part of Earth's protective ozone layer
2 million years ago, devastating some forms of ancient marine life,
according to a new theory presented at this week's meeting of the American
Astronomical Society.

The new theory brings together puzzling clues from several different fields
of research, including paleontology, geology and astronomy.

Narciso Benítez, an associate research scientist in astronomy in the Krieger
School of Arts and Sciences at The Johns Hopkins University, says the
"missing smoking gun" that brought the clues together was the revelation
that a stellar cluster with many large, short-lived stars prone to producing
supernovae had passed near Earth's solar system several million years ago.

That discovery, made by co-author and Space Telescope Science Institute
astronomer Jesús Maíz-Apellániz, led Benítez to check the scientific record
for potential effects of nearby supernovae on the Earth.

"Nobody had realized that this cluster of stars that Jesús had tracked,
which is known as the Scorpius-Centaurus OB association, could have been so
close to Earth during the past several million years," Benítez says. "And
when I did a search, one of the first things that popped out was a 1999
finding where a team of German astronomers led by Klaus Knie detected the
presence of a highly unusual isotope of iron in samples of the Earth's crust
drilled from the deep ocean bottom."

Knie had proposed that the iron isotope was debris from a recent supernova
explosion that took place close to Earth. But astronomers had no plausible
candidates for such a nearby explosion until Maíz-Apellániz's work with the
Scorpius-Centaurus association, which is also being presented at this week's
meeting of the American Astronomical Society.

Benítez compared data produced by Maíz-Apellániz and Knie's results, and
found "very good agreement, both in the amount of iron deposited and in its
time distribution."

Benítez consulted with his wife, Matilde Cañelles, an immunologist at the
National Institutes of Health who had done her master's thesis on
microscopic algae, to learn if the paleontological record included an
extinction that had unusual characteristics suggestive of a potential link
to a supernova.

"Such an extinction would have had especially pronounced effects on the
plankton and the marine organisms," Benítez explains.

Cañelles pointed out that evidence existed for a widespread extinction of
plankton and other marine organisms about 2 million years ago, and noted
that scientists are still debating the possible causes of the event.

"Based on the minimal distance we expected for a supernova in the
Scorpius-Centaurus association at that time, I then did some calculations to
explore the potential effects on Earth," says Benítez.

He found that cosmic ray emissions from a supernova could have had a
potentially devastating effect on the Earth's ozone layer, an upper layer of
the atmosphere that absorbs harmful ultraviolet emissions from the sun and
other sources.

"This would have produced a significant reduction in phytoplankton abundance
and biomass, with devastating effects on other marine populations, such as
bivalves," Benítez says.

Benítez emphasizes that the theory, while provocative, is consistent with
the paleontological evidence, and also with the pattern of movement of the
Scorpius-Centaurus group, which would have been at its closest to Earth at
that time.

He concedes, though, that more evidence will be needed to firmly establish
the theory. In particular, more detailed searches for supernova-produced
isotopes in the geological record would show whether there was a tight
temporal correspondence between the supernova explosion and the extinction
event. Isotope searches could also offer crucial information about the
physical processes involved in supernova explosions.

"People study supernovae using telescopes and supercomputer simulations. In
the future, some of the most relevant information in this field may be found
in the deep ocean floor," says Benítez.

While the new theory may further heighten concern about human impacts on the
ozone layer today, Benítez and Maíz-Apellániz say there's no need to worry
about another supernova in the Scorpius-Centaurus group affecting Earth in
the near future. The next star due to explode in the association, Antares,
is now located at a distance of almost 500 light-years, which is too far
away to have a significant effect on our planet.

This research was funded by an Advanced Camera for Surveys grant from NASA,
the Johns Hopkins Center for Astrophysical Sciences, and a grant from the
Space Telescope Science Institute.


>From Paal Brekke <>

SOHO's private view of a sunbathing comet

As expected, the periodic comet 96P/Machholz 1 entered the LASCO C3 field of
view on January 6th.  The comet, travelling from South to North, will remain
in the field of view until January 10th.  This comet is a short period comet
discovered by Don Machholz on May 12, 1986.  It orbits with a period of
about 5.3 years and at closest approach to the Sun is about 27 solar radii

We had expected this comet to reach a peak brightess of about 2nd magnitude.
However, it has far exceeded this, reaching a peak brightness of amost -1,
thus 15 times brighter than some people had estimated.

One reason we're interested in this comet is that it can be observed
throughout virtually it's entire orbit. Because it doesn't stray too far
away, it can be observed at aphelion (~5 AU).
Because it gets so close to the Sun, it can be observed with coronagraphs.
This gives us a great opportunity to follow the evolution of the comet.

Updating mpegs where people can follow the comet acress the LASCO filed of


Webstories on:

NOTE!!!! Our webserver is allready slow due to all the request from the
images.. so please be patient..

You can find a few still and mpegs here in case the SOHO web site is to
slow. Please don't link this link on your webstory though:


Paal Brekke,
SOHO Deputy Project Scientist  (European Space Agency - ESA)

NASA Goddard Space Flight Center,      Email:
Mail Code 682.3, Bld. 26,  Room 001,   Tel.:  1-301-286-6983 /301 996 9028
Greenbelt, Maryland 20771, USA.        Fax:   1-301-286-0264



>From Lew Gramer <>
[as posted on the Meteor Observing Mailing List]

What an intriguing 'CCNet Digest' issue, for folks with an interest in the
theory of meteor shower creation and evolution... But for anyone who lacks a
taste for this kind of theory, please go ahead and hit "Delete" now. ;>

Here's an exciting exchange between the DMS' Marco Langbroek and Dr. Duncan
Steel, regarding the Quadrantid *meteor shower*, and the particular *debris
trail(s)* which result in its extraordinarily sharp peak. Unfortunately, Dr.
Steel's response fell short of being clear, to this inexpert reader? One of
its main points in particular, that regarding the distinction between "new
meteor shower" and "new meteoroid stream", was hard for me to relate to the
discussion?? I am quite sure I'm missing something, and hope Dr. Steel can
correct me. But I interpreted Marco's primary point (and I hope Marco will
correct me if I misattribute him!), to be that the particular "streamlet",
(or "dust trail" in more modern nomenclature??), associated with the QUAs'
PEAK, is just very unlikely to be as old as Dr. Steel's references suggest.

Dr. Steel then discounts this argument, as being based on one questionable
assumption: Namely, that *older* "trails" are statistically likely to be
observed to produce *more diffuse* activity... But based on this amateur's
limited understanding, both of the dizzying variety of forces which act on a
meteoroid stream, and of how such forces may impact the evolution of the
stream, I'm not clear what alternative interpretation(s) Dr. Steel would
suggest be applied to what is obviously very compact activity? Dr. Steel,
are you suggesting that some form of shepherding (similar to the posited
cause of the 1998 "Leonid fireball shower", but affecting a more diverse
range of particle masses), can explain how such a compact peak could be
reconciled with such an old (>1000 year) ejection time? Or is your assertion
that there is no DEMONSTRATED link between the "time compactness" of a
meteor shower feature (like the QUA peak), and "time since ejection" of the
particles which are assumed to produce that meteor shower feature??

In any case, your points very much stimulated my curiosity as an amateur,
Dr. Steel: and in particular, in reading the reference you cite (Jones &
Jones 1993), I was intrigued by the complexity and seemingly magisterial
nature of the ejection/evolution model which the authors used to "create" a
wide array of different observed showers, all from this one parent. If there
have been any follow-up papers published on this particular model, they'd be
very interesting to read. (My ADS search did not seem to turn up any
particular citations to the actual model used by Jones & Jones.)

An additional comment, in re the limited usefulness of meteor observing to
get the "whole picture" of a particle stream's structure & evolution:

>There are other parts to every stream that are separated from us in
>space and time which may not be sampled through meteor techniques.

Dr. Steel, I'm surely (again) missing something, but doesn't this point
assume that we are only discussing meteor observations within some very
limited time horizon? Presumably, observations taken throughout a shower
activity period, over many years (and recall there are more or less reliable
meteor observations going back well over a Century) may gradually reduce,
though admittedly never eliminate, any "sampling bias" produced by using our
home planet and its atmosphere as an observing instrument?

But leaving that aside, I was again confused as to how this point could be
related to the main discussion: In particular, how can one particular
feature, namely the QUA peak, which clearly is amenable to observations from
Earth, somehow be explained by reference to some other structure of the
meteoroid stream which is presumably less readily observed? If this is in
fact the essence of this argument, then how can a test be designed, for the
hypothesis that such "hidden" stream features do in fact exist?

And last but not least (I promise!):

>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.

Apologies, but why is it necessary, in order to disprove the association of
a body with one meteoroid stream, to first also disprove its association
with any given list of other streams? Forgive my naive question: if I had to
guess, based on my limited knowledge, I'd have to assume that there is some
clear evidence suggesting that all these streams MUST be a result of
ejections from the same parent body? What is this evidence?

By the way, in researching this editorial comment, I came on references to a
paper by Jenniskens et al (1997), which is said to clearly imply a
conclusion that the Quadrantids must be comprised of meteoroids ejected some
time in the last 500 years, and no longer. (See one such reference,
below.) Might Doctor J. be willing to comment on this question as well?

Thanks to you both for an enjoyable exchange via CCNet, as well as any
further clarification anyone may choose to provide us on 'meteorobs'... (And
thanks for a new word, Marco! "Sensu lato"="in a broad sense". ;>)

And apologies ahead of time, if my comments have missed the point! :)

Clear skies to all,
Lew Gramer

ref: Williams, Iwan P., Collander-Brown, S.J., 1998MNRAS.294..127W.

[This paper cites among many other sources, Dr. Steel's work on meteoroid
stream creation and evolution, and then goes on to suggest a THIRD
possibility for the parent body of the QUAs, Asteroid 5496 (1973 NA).]


>From Drake A. Mitchell <>

Dear Dr. Peiser,

First, in response to recent thoughts of a database for suspected
astroblemes, may I point out
the 74-crater database (Jetsu 1997) that includes age and error from 6
sample sets; 2 copies are @NASA/Goddard's ADC,
and @CDS/Strasbourg, France:

Jetsu (University of Helsinki, Observatory, P.O. Box 14, 00014
Helsinki,Finland; NORDITA, Blegdamsvej 17,
2100 Copenhagen, Denmark)
is motivated by time-series analysis of (a)periodicity: Astron. Astrophys.
353, 409-418 (2000).

Secondly, based upon the AIAA/IAC's 6th Workshop Report (March '01), the
award of new public funds in the UK for the NEO hazard, and the significant
prospects for both ProSpace's upcoming MarchStorm and the AIAA-NAS World
Space Congress, Houston TX, 10-19Oct02, I expect a breakthrough this year on
Planetary Defense issues in the United States. Key leverage is to be gained
by focusing on the issues of a) urgency and b) economic modeling.


Drake A. Mitchell,


>From Jens Kieffer-Olsen <>

Dear Benny Peiser,

Richard Stenger wrote for CNN Sci-Tech:

> 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.

but neither he (nor for that matter the Times of India) mentioned the likely
impact speed of the object, which is a crucial parameter if one is to
envisage the damage it can cause.

Furthermore, to the layman an asteroid 'the size of Texas' is capable of
destroying just that, an area like Texas. Rather than be glued by scientific
honesty to the irrelevant (for the public) diameter of such threatening
objects, let's be innovative and describe their size in terms of footprint
upon impact. Be aware CNN, 2001 YB5 is an asteroid with a footprint the size
of Texas!

If you will pardon me for drawing an unusual parallel, this terminology
seems to provide a more unbiased projection than the term 'street value'
used by police to inform the public of the magnitude of a drug bust!

Yours sincerely
Jens Kieffer-Olsen, M.Sc.(Elec.Eng.)
Slagelse, Denmark


>From Colin Keay <>

Dear Benny

The item in CCnet 4/2002 citing the Observer article on the Myths of
Chernobyl is most welcome since it shows how many facts of the matter have
been distorted or ignored in the past.

I am grateful that you brought the article to my attention because it
supports the case presented in my recent booklet "Nuclear Energy Fallacies -
Forty Reasons to Stop and Think", Enlightenment Press, 2001, ISBN
0-9578946-0-0. The book lists and deals with forty published fallacies about
nuclear energy and a companion book "Nuclear Radiation Exposed - A Guide to
Better Understanding" ISBN 0-9578946-1-9 challenges the misconceptions about
nuclear radiations.

I am in the process of sending free copies of these books to politicians and
the media in a personal effort to improve their knowledge and understanding
of nuclear issues because Australia's vital replacement nuclear research
reactor is under severe threat from those with an
anti-nuclear agenda. This effort is costing me quite a lot so I am selling
extra copies to help defray my publishing expenses.

Within Australia they can be obtained from the publisher for A$7 each
posted, while for other countries the cost is US$5 per copy posted by air
mail. US currency is acceptable (no plastic!) to the Enlightenment Press, PO
Box 166, Waratah, NSW 2298, AUSTRALIA.

Thank you.
Colin Keay
Physics Department
University of Newcastle


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