CCNet, 37/2003 -  4 April 2003

"A new study of several meteorites collected on Earth and thought to have come from the
  same large asteroid reveal the structure of the parent space rock to have been something
like an onion, with layer upon layer of differing structure."
--Robert Britt,, 2 April 2003

"Looking from Earth, it's hard to keep an eye on rocks in the Asteroid Belt that are less
  than 10 kilometres in diameter. We don't know what's flying around up there, or if anything
may be on track to hit us. The Bering probe will help us gain a much better perspective on
interplanetary asteroids."
--Anja C. Andersen, Niels Bohr Institute, Copenhagen 

"For the past century the world has got steadily better for most people. You do not believe
that? I am not surprised. You are fed such a strong diet of news about how bad things are
that it must be hard to believe they were once worse. But choose any statistic you like and
  it will show that the lot of even the poorest is better today than it was in 1903."
--Matt Ridley, The Guardian, 3 April 2003


    Nature, 3 April 2003

    Ron Baalke <>

    Deep Impact Project <>

    The Copenhagen Post, 3 April 2003

    BioMed Central, 3 April 2003

    Jens Kieffer-Olsen <>

    Michael Paine <>

    Stephen Ashworth <>

     Michael Martin-Smith <>

     The Guardian, 3 April 2003


>From, 2 April 2003

By Robert Roy Britt

A new study of several meteorites collected on Earth and thought to have come from the same large asteroid reveal the structure of the parent space rock to have been something like an onion, with layer upon layer of differing structure.

The asteroid, long ago destroyed in a collision, was once hot enough to have a molten core and cooled from the outside inward, the research shows, confirming a long-held expectation that had eluded supporting research.

Asteroids are leftovers of planet formation. While some rocks got together to build planets about 4.5 billion years ago, a bunch never achieved as much. Most of this debris now orbits the Sun in the so-called asteroid belt, between Mars and Jupiter. Collisions in the belt have been frequent through time, and some of the resulting smaller chunks make their way to Earth, where they fall as meteorites. 

Scientists see these meteorites as a collective window to planet formation and the evolution of the early solar system.

Researchers already suspected that the initial asteroids, sometimes called planetesimals because they were like precursors to planets, were heated internally by the decay of a short-lived aluminum isotope that was common in the early solar system. The middles of some asteroids would have melted.

The new work, led by Mario Trieloff of the University of Heidelberg, Germany, examined crystals in several meteorites known as H-group chondrites, all of which were presumed to have come from the same parent asteroid. Some of the crystals were damaged by spontaneous fission generated long ago by decaying plutonium. The damage was healed by high temperatures -- like those occurring in the center of an asteroid -- but remain in meteorites that were cooler, presumably from outer layers of the asteroid.

This allowed Trieloff's team to create a temperature map of the original asteroid. The map confirms a suspected layered composition, the so-called onion model.

"This cooling behavior is in perfect agreement with what we expect, if an asteroid is heated by an internal heat source that comes from the rocks itself," Trieloff said. The research will be detailed in the April 3 issue of the journal Nature.

Scientists have sought confirmation of the onion model for decades, but it was lacking. Perhaps, some thought, the H-chondrites came from many different asteroids, instead of one.

John Wood of the Harvard-Smithsonian Center analyzed the research for Nature.

Trieloff and his colleagues "now dispel these doubts," Wood writes, by showing that the chondrites "can be fitted into a straightforward model of a planetesimal with a radius of about 100 kilometers [62 miles] and an onion-shell structure, which was internally heated ... and cooled over about 100 million years."

The study looked at just one sort of asteroid, however, and it does not represent the structures of asteroids in general. Trieloff points out that there are about 10 different major chondrite classes in meteorites, material that represents "at least 50 originally different asteroids."

Meteorites in other chondrite classes typically do not show the diversity of types that would indicate the extensive layering of a parent object as found in the new study. Among these are so-called carbonaceous chondrites.

Trieloff told that the parent bodies of these other chondrites might either have formed a few million years later, after the aluminum isotope had already decayed, and so never had a chance to grow so hot. Or the parent asteroids might simply have been smaller (size affects heat, too).

Yet another class of chondrites (called L and LL) represent asteroids that probably did have a layered structure but might have broken apart before cooling down, thereby eliminating the sort of evidence that the new study looked for, Trieloff said.

Copyright 2003,


>From Nature, 3 April 2003     

For the first time we now have a record of the structure and cooling history of a planetisimal from the early Solar System, from its formation 4.6 billion years ago to its existence as a cool, stony asteroid. Much later it was to fragment, and parts of it fell to Earth. Measurement of plutonium-244 and argon isotope thermochronologies in a collection of meteorites classified by their chemical composition as 'chondrite H', and thought to have originated from different depths within the same asteroidal body, shows how rapid accretion, in just a few million years, was followed by internal heating to produce a layered body. Heat production was insufficient for the separation of a molten iron core, and after 160 million years of cooling the rocks at the centre had reached 390 K.

Structure and thermal history of the H-chondrite parent asteroid revealed by thermochronometry
Nature 422, 502-506 (2003); doi:10.1038/nature01499


>From Ron Baalke <>
April 2, 2003
Asteroid Vesta
Credit: Don Pettit, ISS Expedition 6 Science Officer, NASA

Picture this: You're at home in your living room. It's dark outside. A few of the brightest stars shine in through the window. Meanwhile, two hundred million kilometers away, a nearly invisible asteroid glides through space. You grab your camera, point, click, and capture the space rock on film--right through your living room window. No problem?

It wasn't for International Space Station Science Officer Don Pettit, who enjoys space-dark skies and the clearest living room window in the solar system. On March 24th he pointed his digital camera out the station's Destiny Lab window and snapped this picture of asteroid Vesta in the constellation Virgo. Vesta is so big--about 500 km wide--that astronomers consider it to be a minor planet. Even so, distant Vesta is barely visible to the naked eye from the darkest and clearest observing sites on Earth. Taking its picture through any window is remarkable.

The brightest star in Pettit's photo is epsilon Viriginis. Also known as Vindemiatrix, this star is 60 times more luminous than the Sun and lies 100 light years away. The faintest stars in the photo are approximately 16 times fainter than you can see with your naked eye--i.e., the limiting magnitude was 9. In a larger version of this image you might also notice some dim smudges. These are galaxies in the Virgo Cluster about 50 million light years away. "The space station functions very well as a platform for astrophotography," notes Pettit.


>From Deep Impact Project <>

New Launch Date for Deep Impact
Deep Impact Project
April 1, 2003

A new launch window is announced for the Deep Impact project, the first mission to look deep inside a comet. Technical and management issues, including contamination in the propulsion system and late deliveries of key spacecraft components, resulted in delays in the pre-flight testing
schedule. These concerns led Deep Impact Principal Investigator, Mike A'Hearn, to recommend to NASA a delay of launch. A launch window beginning December 30, 2004, previously identified as a back-up date, provides more thorough testing for the spacecraft systems before launch and allows the spacecraft to arrive at Comet Tempel 1 to impact it as originally scheduled on July, 4, 2005. NASA management approved the recommendation.

Old Trajectory Diagram:

New Trajectory Diagram:

Deep Impact will be the first mission to make a spectacular, football-stadium-sized crater, seven to 15 stories deep, into the speeding comet. Dramatic images from both the flyby spacecraft and
the impactor will be sent back to distant Earth as data in near-realtime. These first-ever views deep beneath a comet's surface, and additional scientific measurements will provide clues to the formation of the solar system. Amateur astronomers will combine efforts with astronomers at larger telescopes to offer the public an earth-based look at this incredible July 2005 encounter with a comet.


>From The Copenhagen Post, 3 April 2003

With the space-age Bering Probe, astronomers will develop groundbreaking new technology to study rogue asteroids

Leading Danish astronomers have launched an ambitious plan: a team at the Niels Bohr Institute hopes to become the first in the world to develop technology capable of probing the Asteroid Belt. The new Danish probe would investigate asteroids up to 400 kilometres from Earth, and provide much more effective information on rogue space rocks that may be on a collision course with the planet. 

Researchers from Denmark's Technical University and the Niels Bohr Institute have begun the developmental stages of the Bering space probe, named in honour of the Danish explorer. Equipped with a telescope, cameras, a magnetometer, and a computer, Bering will investigate asteroids travelling between Mars and Jupiter. 

The Bering probe will be aimed primarily at smaller asteroids, which pose the greatest threat of colliding with this planet. 

'Looking from Earth, it's hard to keep an eye on rocks in the Asteroid Belt that are less than 10 kilometres in diameter. We don't know what's flying around up there, or if anything may be on track to hit us. The Bering probe will help us gain a much better perspective on interplanetary asteroids,' said Niels Bohr Institute astronomer Anja C. Andersen, speaking with daily newspaper Berlingske Tidende. 

According to the newspaper, earthly collision by an asteroid just two kilometers in diameter could unleash a global catastrophe, wiping out huge segments of the planet's population. 

A final price-tag on the Bering project has been estimated at DKK 1.2 billion (162 million euros). Researchers are appealing for financial aid from global (sic) space organisations.

All rights reserved CPHPOST.DK ApS


>From BioMed Central, 3 April 2003

Is there life on Mars? It's possible, but it may not Martian, say scientists. New research, published in the open access journal BMC Microbiology, suggests that conditions on Mars are capable of supporting dormant bacteria, known as endospores. This raises concern about future attempts to detect Martian life forms because endospores originating on Earth could potentially hitch a ride to Mars and survive on its surface.

Soil on Mars is thought to be rich in oxidising chemicals that are known to destroy life. The high levels of ultraviolet radiation on the surface of the planet make it unlikely that any organism could survive. Ronald Crawford and colleagues from the University of Idaho have investigated whether bacterial endospores can exist in Mars's hostile environment.

Endospores are a survival form of bacteria, formed when they find themselves in an unfavourable environment, and are perhaps the most resilient life form on Earth. They are resistant to extreme temperatures, most disinfectants, radiation, drying, and can survive for thousands of years in this dormant state. There is even evidence that they can survive in the vacuum of space. Given the possibility of endospores hitching a lift on spacecraft bound for Mars, Ronald Crawford and his colleagues investigated whether endospores could survive in a simulated Martian environment.

Martian soil was created by mixing dry sand containing endospores with ferrate. The soil was then left at -20 oC and exposed to high levels of UV light for six weeks. These conditions were designed to simulate the dry, cold, oxidizing environment found on Mars. Subsequent analysis of the soil showed that endospores were still alive below a depth of 5mm, suggesting that life is possible in these hostile conditions.

The authors speculate, "that if entities resembling bacterial endospores were produced at some point by life forms on Mars, they might still be present and viable, given appropriate germination conditions."

Although the researchers have not found direct evidence for life on Mars their research does throw up a potential problem with future space missions. The survival of endospores in such adverse conditions raises the possibility that bacterial endospores could travel to Mars on the surface of spacecraft and survive on Martian soil. This could seriously compromise future efforts to establish whether there is, or has been life on Mars, as it would be difficult for researchers to know whether any endospores found originated from Earth or Mars.

Whilst this work establishes that bacterial endospores can survive exposure to the conditions probably found on Mars, it should be noted that it was not possible to test whether their simulated Martian environment would kill endospores over a geological timescale.

Further Information:

This article in freely available in the open access, peer reviewed journal, BMC Microbiology

Contact one of the authors, for further information about this research

Ronald L. Crawford
Environmental Research Institute
and Department of Microbiology,
Molecular Biology & Biochemistry,
University of Idaho,
Moscow, USA




>From Jens Kieffer-Olsen <>

Dear Benny Peiser,

Tumbling Stone, 23 March 2003 by Andrea Carusi, which I feel deserves a comment:

> The document has not yet been finalized and therefore cannot
> be reported here; however, a few comments on its "spirit" can
> be made. A first important point is that the NEO threat is
> recognized as real, although of very low frequency.

'Of very low but unpredictable frequency' would be a better wording, keeping a balance between scaremongering and downplaying the risk.

> A second point that has been raised is that the scientific
> investigations on all phenomena related to impacts should
> receive more attention and, in the end, more funds. The link
> between scientific research and civil defense initiatives has
> been stressed, because the science findings are essential to
> characterize the risk and to indicate the most effective ways
> of planning mitigation measures.

Actually, I doubt that it can be deemed cost-justified to involve civil defense on a detailed scale, until a threat is for real. But identifying NEO orbits early on, such that the warning
time before impact is maximised, is a purpose to which many more funds should indeed be given.

> A third point concerns international collaboration. It is clear
> that impacts are a potential hazard that involves, by its very
> nature, many countries; actions should therefore be taken to
> improve the international collaboration both in finding the
> objects and in analyzing possible countermeasures.

I don't see why finding the objects needs international collaboration at all. Observations need to be communicated as happens already to-day, but independent search programs are warranted in a number of countries for several good reasons. Any data received from probes in solar orbits would
be scrutinized first by scientific or military personnel of the country that built the probe. As for analyzing counter-measures to-day, it seems a futile exercise except for NASA and their
Russian counterpart, although of course ESA and China may have a role to play in some future mitigation strategy.

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


>From Michael Paine <>

Dear Benny

For those who, like me, have difficulty with the OECD website the paper by Clark Chapman is at
Clark's homepage is but he hasn't listed the paper there yet.

Michael Paine


>From Stephen Ashworth <>

Dear Dr Peiser,

It is not clear what motivates Andrew Glikson's extraordinary cry of despair (CCNet 15/2003 - 2 April 2003, item 8).

If his references to the "global market force" and the "desert sky god" are intended as references to the recent military conflict in Afghanistan, or (less plausibly) the current one in Iraq, then his analysis omits a number of relevant factors. These include the progressive nature of human evolution (amply illustrated today in Iraq, where one side is fighting with one hand tied behind its back and subject to the court of world opinion) and the demonstrated superiority of the global market economy as a system for generating wealth.

It is also unclear what his references to "destruction of the biosphere" and "planetary ecocide" are apropos of, given that environmental awareness in the rich world has been growing over the past 30 years, and that near-future technologies will one day be vital in the prevention of that
tragedy on Earth due to the long-term increase in solar luminosity.

Stephen Ashworth
Fellow of the British Interplanetary Society
3 April 2003

Stephen Ashworth, Oxford, U.K.


>From Michael Martin-Smith <>

Dear Benny,

Judging from the personal testimony of many Iraqi exiles around the world, it seems clear that the postulated health hazards of the present war are vastly dwarfed by the well-known health hazards of being ruled by Saddam Hussein and his totalitarian National Socialist (Ba'ath Party) regime. A Manifesto for this Party, both in theory and practice,  would differ from Hitler's "Mein Kampf" chiefly in the substitution of the word "Arab" for "Aryan". The health hazards inherent in Hitler's "Mein Kampf" and its anti-democratic/anti-Judaic creed are the stuff of history; the same ideas, intrinsic alike to Ba'athism, are now potentially even more hazardous to
health, since today's Israelis, unlike the victims of the Holocaust 60 years ago, are not without the means of massive retaliation.

We would do well to remember this, I think

Michael Martin-Smith


>From The Guardian, 3 April 2003,12981,928170,00.html

Acclaimed author Matt Ridley on why it's high time we cheered up about the new technologies

If you debate the new genetics in Europe and America these days you get asked the same question in two different ways. The average European says, with dread: "How do we stop people doing x?" The average American says with excitement: "When will I be able to do x?" For x, read "test myself for future dementia risk," "change my unborn children's genes," or even "fill my blood vessels with nano-robots to enable me to live to 150".

To the jaded European palate, the American attitude seems silly and irresponsible. Caution should be the watchword for all new technology. I beg to differ. I think the American optimism is necessary and responsible. It is the European pessimists who are in danger of causing real harm. Caution has risks, too.

My techno-optimism is deeply unfashionable in Europe, where Jeremiah is treated as a serious, cautious and - let's face it - cool guy, but Pollyanna is a silly twit.

We discuss the potential drawbacks of genetic testing or genetic modification of crops. We do not discuss the suffering and environmental damage that will be caused by holding back innovation.

I am not arguing that all new technologies are risk free. Reproductive cloning, for example, carries a 30% risk of producing a bodily deformity, 15 times the normal rate. To use this technology on human beings is wrong precisely because it is unsafe.

I am arguing that the debate is unbalanced here because it is complacent about the imperfect present. As James Watson, an unabashed proponent of more genetic testing, has said: "If there is a paramount ethical issue attending the vast new genetic knowledge created by the Human Genome Project, in my view it is the slow pace at which what we know now is being deployed to diminish human suffering." He points out that almost no pregnant women are offered screening for fragile X syndrome, an easily identified genetic cause of terrible mental retardation. Ethics cuts both ways.

This applies even to esoteric discovery. In Europe most people think the discovery of genes that influence human behaviour must inevitably lead to a sort of behavioural apartheid in which the genetically disfavoured are abandoned to their fate.

But examine what actually happens when society concludes that a particular behaviour is innate. Dyslexia and autism are good examples. In the 1960s, most people believed they were caused by nurture - by parenting or schooling. Now most people believe they are primarily genetic. Has this change led to dyslexics and autistics being thrown on the educational scrap heap? Quite the reverse: a belief in genetic determinism has been accompanied by a renewed determination to find remedial education that works.

Far from imprisoning us in fate, self knowledge about the causes of our behaviour will liberate people to make choices: as the philosopher Daniel Dennett argues, more knowledge brings more free will. The horrors of eugenics were helped not by biological discoveries - the eugenic movement pre-dated the rediscovery of the gene in 1900 by 26 years - but by biological ignorance. Demagogues could whip people into a frenzy about genetic deterioration only because so little was known about real genes.

Since then, the history of biology is a history of worrying too much and hoping too little. In 1975 at Asilomar in California scientists in effect called a five-year moratorium on the new technology of microbial genetic engineering until regulation caught up. Responsible? Perhaps, but the effect was to delay by five years the production of vital drugs for haemophiliacs, diabetics and people deficient in the human growth hormone. The first and last groups were, as a result, more exposed to Aids and new variant CJD respectively.

Soon after, many people feared that test-tube babies would lead to eugenics: to people choosing to use the eggs of beauty queens or the sperm of Nobel prize winners. In fact, businessmen tried to sell both and failed. People use in-vitro fertilisation mostly to have their own babies, not somebody else's.

Then along came genetic fingerprinting, invented by Alec Jeffreys in Leicester in 1985, and everybody worried so much about its potential for incarcerating the wrong criminals that almost nobody noticed until recently that it was the ideal tool for exculpating the wrongly convicted. To date, the Innocence Project in New York has used DNA to exonerate more than 100 wrongly convicted people, some of whom were on death row. That project is run by Barry Scheck and Peter Neufeld, the two lawyers who helped get OJ Simpson off by challenging DNA evidence: they are now its fans.

Then we were told that genetic modification of food would lead to the use of more chemical sprays. The opposite proved true: GM cotton growers in India, Australia and China are spraying less than half as much pesticide on their crops; GM corn growers in the United States are spending less than before on insecticide. British growers of GM sugar beet are spraying herbicide once instead of five times. The birds, butterflies and flowers are coming back into the fields where GM crops are grown.

Of course, the organic farming lobby argues that it, too, can bring back wildlife. But only at a price. Because organic crops require nitrogen grown elsewhere rather than manufactured from the air in a factory, organic farming is land-hungry. The economist Indur Goklany has calculated that if the world tried to feed its current six billion people using the (mainly organic) technologies and yields of 1961, it would require 82% of land area to be cultivated instead of 38%. That means ploughing up the Amazon, irrigating the Sahara and draining the Okavango.

Speaking of food, in Europe it is common to hear the argument that the world now produces enough food without GM. Yes, but how did it achieve this? By rapidly adopting fertiliser, pesticides and high-yielding varieties. This "Green Revolution" depended on genetically new varieties created by artificial mutation using nuclear radiation and chemical mutagens.

Ah, say the pessimists, but the green revolution did not solve all poverty and malnutrition. True - which is precisely why it is so important to press ahead with new technologies to solve the remaining problems. There was no golden age: old-fangled farming caused environmental and humanitarian problems, too.

"Organic farming is sustainable," says Indian biotechnologist CS Prakash. "It sustains poverty and malnutrition." DDT was brought in to replace arsenic compounds that left birds dead in the fields. Or, as a biotechnologist said to me the other day: "If you think GM disrupts the environment, try watching what a plough does to soil structure".

For the past century the world has got steadily better for most people. You do not believe that? I am not surprised. You are fed such a strong diet of news about how bad things are that it must be hard to believe they were once worse. But choose any statistic you like and it will show that the lot of even the poorest is better today than it was in 1903. Longevity is increasing faster in the poor south than in the rich north. Infant mortality is lower in Asia than ever before. Decade by decade per-capita food production is rising.

Here at home, we are healthier, wealthier and wiser than ever before. Pollution has declined; prosperity increased; options opened.

All this has been achieved primarily by that most hated of tricks, the technical fix. By invention, not legislation.

My point? Simply this: if you asked intellectuals at almost any time since Malthus to talk about the future, they would have been pessimistic and they would have been wrong. The future (actual) has consistently proved better than the future (forecast).

Malthus said we could never grow enough food; the Club of Rome said the oil would soon run out; Paul Ehrlich said the population would expand until it crashed.

(Population is the one issue where my optimism relies on a miracle. Given unlimited food, other species expand their numbers until they crash. Human beings, instead, go through something called the demographic transition, when they voluntarily adjust their birth rate once infant mortality decreases. It happened in Sweden first, Britain next, Thailand recently and it's happening in Bangladesh now. The forecast peak size of the world population has fallen from 15bn to 9bn in just 25 years. As I said, a miracle.)

What accounts for Europe's techno-pessimism? I suspect environmentalists merely milk it, rather than create it. Novelists and screen writers have a lot to answer for. How many movies have you seen set in the future in which you thought - what a nice place to live? Thought not.

The future is always depicted as a place where a technical fix has gone wrong, where androids stalk a devastated urban landscape. I have recently noticed a lot of people suddenly worrying about nanotechnology. Could Michael Crichton's "Prey" have anything to do with this?

Many people in the environmental movement will object that they have nothing against new technology per se, but they distrust its ownership by big corporations. Yet their actions often belie the distinction. When presented with a biotechnology that was developed in the public sector and is freely available to all in the developing world, they still object to it. A good example is 'golden rice'.

In the 1990s Ingo Potrykus genetically engineered some strains of rice to contain a natural vitamin A precursor precisely because he was affronted by the fact that half a million children go blind every year in the third world for lack of vitamin A. He gave up his intellectual property rights, and persuaded Syngenta and other companies to waive their patents so that he could give the rice away for free in poor countries.

Yet the crop remains tied up for years to come awaiting regulatory approval as a "drug" because of precautionary regulations urged on third world countries by environmental groups. Greens argue that Potrykus's rice should never be used because a person would need to eat up to nine kilograms a day to get enough vitamin A and because there are better ways to get vitamins to the poor. The first assertion is false - the true figure is up to 200 grams. As for the second, if greens know a better way to get vitamins to the poor, let them do it. At least Potrykus acts, rather than just postures.

I met Potrykus recently in Monterey in California. He was filming harlequin ducks in the harbour: he is as passionate about nature as he is about humanitarianism. We talked about birds and how to restore the British skylark. We agreed that the invention of winter wheat in the 1970s, not pesticides, was the chief problem because it robbed the species of its winter stubble habitat. Spring wheat is now uneconomic to produce. It should be possible now, he said, to genetically-modify wheat so it can be just as productive if planted in the spring.

I put that idea to the John Innes Centre, Britain's leading plant biotechnology research centre. Nobody will fund environmental genetic modification on wheat these days, I was told: the greens have frightened off the public funds, and the private funders have gone back to inventing new chemical sprays because they get less flak that way. How sad for skylarks.

The burden of proof should be on those who think the present cannot be improved upon.

Matt Ridley's new book, Nature via Nurture: Genes, Experience and What Makes Us Human, published by 4th Estate, priced £18.99, is out now.

Copyright 2003, The Guardian

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>From Discovery News, 3 April 2003

By Larry O'Hanlon, Discovery News

April 3, 2003 - The evidence is still skimpy, but there is a chance that the dino killer asteroid was not alone when it walloped the Earth 65 million years ago.

A possible second crater, at least as big or bigger than the famous Chicxulub crater off Mexico's Yucatan peninsula, may have been created by a second hit moments after Chicxulub and off the coast of Maine.

"It probably is a crater, but we really don't have age data," said marine geologist Dallas Abbott Lamont-Doherty Earth Observatory at Columbia University.
What makes Abbott suspect a crater is a large and unexplained difference in the magnetism of the crust in the Gulf of Maine. Then there is an arrangement of ridges on land that channel rivers and streams in Maine and Massachusetts along arcs that might be ridges of the western part of an eroded crater, said Dominic Manzer a NASA spacecraft engineer.

Abbott and Manzer presented their very preliminary work on what they are calling the Small Point crater late last week at a regional meeting of the Geological Society of America in Halifax, Nova Scotia.

Other asteroid and crater specialists are not so optimistic that the Gulf of Maine will yield a crater that corresponds with the end of the dinosaurs - the Cretaceous-Triassic (K-T) boundary 65 million years ago.

"There is no evidence of an impact event," said David Kring of the Lunar and Planetary Laboratory at the University of Arizona. What's more, if there were a second impact, said Kring, there would be a second blanket of debris at the K-T Boundary, which so far is not there.

Abbott agrees that the evidence is slim at this point. In fact, glaciers of past ice ages probably scoured away all the real rock evidence on the surface long ago, she said. That's why she hasn't tried to publish any official papers on the matter.

Instead, she intends to start looking further south, in the Martha's Vineyard area, for any impact-related rocks of the right age that might have been dropped there after the glaciers retreated.

If there was a double impact, said Manzer, it could have been that the asteroid or comet broke up before hitting Earth, leaving a rapid-fire line of craters, as has been seen on other planetary bodies in the solar system.

Copyright 2003, Discovery Channel

CCCMENU CCC for 2003