Alex Ruzicka, Portland State, Geology Dept.
Winner in Earth Sciences
Daily Vanguard- 27MAY09
When the Buzzard Coulee meteorite fell in Canada last Thanksgiving, Professor Alex Ruzicka was on the case to classify the meteorite.An expert in meteorites, Ruzicka is also the co-founder and director of the Cascadia Meteorite Laboratory, which provides education outreach to people in the area on meteorites. It is the only meteorite laboratory in the Pacific Northwest. ...
http://www.dailyvanguard.com/cutting-edge-research-nationally-recognized-professors-1.1754591
27 May 2009
Tagish Lake Meteorite Makes More News 27MAY09
A more organic meteorite
Science News Tue, 26 May 2009 13:01 PM PDT
Some may contain more formic acid, a precursor to life, than previously thought ...
Meteorite Contains Record Amount of Organic Compounds
redOrbit Tue, 26 May 2009 12:12 PM PDT
Scientists have reported the discovery of formic acid at record levels in a meteorite that splashed into Tagish Lake in Canada in 2000.Formic acid is the simplest carboxylic acid. It is rich in carbon, and it has been linked to the origin of life. ...
Space rock yields carbon bounty
BBC News Tue, 26 May 2009 06:42 AM PDT
A meteorite that crashed to Earth in 2000 has shown an abundance of a chemical likely to have been involved in the origins of life. ...
Space rock yields important 'ingredient in kitchen' on Earth before life began
New Kerala Wed, 27 May 2009 04:34 AM PDT
London, May 27: Scientists have found formic acid, a molecule implicated in the origins of life, has been found at record levels on a meteorite that fell into the Tagish Lake in Canada in the year 2000. ...
Science News Tue, 26 May 2009 13:01 PM PDT
Some may contain more formic acid, a precursor to life, than previously thought ...
Meteorite Contains Record Amount of Organic Compounds
redOrbit Tue, 26 May 2009 12:12 PM PDT
Scientists have reported the discovery of formic acid at record levels in a meteorite that splashed into Tagish Lake in Canada in 2000.Formic acid is the simplest carboxylic acid. It is rich in carbon, and it has been linked to the origin of life. ...
Space rock yields carbon bounty
BBC News Tue, 26 May 2009 06:42 AM PDT
A meteorite that crashed to Earth in 2000 has shown an abundance of a chemical likely to have been involved in the origins of life. ...
Space rock yields important 'ingredient in kitchen' on Earth before life began
New Kerala Wed, 27 May 2009 04:34 AM PDT
London, May 27: Scientists have found formic acid, a molecule implicated in the origins of life, has been found at record levels on a meteorite that fell into the Tagish Lake in Canada in the year 2000. ...
26 May 2009
Students search for space rocks
Meridian Booster, Lloydminster
The kids found their first meteorite before the search even started, right by the road while they were lining up in a straight line. (more)...
Meridian Booster, Lloydminster
The kids found their first meteorite before the search even started, right by the road while they were lining up in a straight line. (more)...
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Climate History Of Arctic Illuminated By Study Of 3.6-Million-Year-Old Meteorite Impact Crater In Siberia 26MAY09
Climate History Of Arctic Illuminated By Study Of 3.6-Million-Year-Old Meteorite Impact Crater In Siberia
Science Daily - May 25
Scientists have studied the El'gygytgyn meteorite impact crater in Arctic Siberia. They found, from analyses of the drill cores, new information about the formation of the impact crater, as well as information they can use more fully to understand the climate history of the Arctic.
Science Daily - May 25
Scientists have studied the El'gygytgyn meteorite impact crater in Arctic Siberia. They found, from analyses of the drill cores, new information about the formation of the impact crater, as well as information they can use more fully to understand the climate history of the Arctic.
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25 May 2009
Yuba City, California Fireball 10MAY09 25MAY09
photo:YCSentinel
Yuba City, California Fireball of 10MAY09
Time: 20090510_0341 PDT
START RA 19 hrs 41'Dec = 21 deg
END:RA 22 hrs 35'Dec = -10 deg 11'
This fireball was a little over 7 seconds and appears to travel on the celestial equator.
Duration = 7.5 seconds.
Brightness = 1/2 full moon
Start Az. = 154 Deg. True North
Start Elev. = ~25 Deg
End Az = 112 Deg. True North
End Elev. = ~10 Deg
Report was held back because of its somewhat regular & pulsation during flight. This fireball was esthetically pleasing, but did not detonate, appearing to burn itself out.
Reported by YCSentinel 21MAY09
Příbramský meteorit vynesl české vědce na špičku světové astronomie 25MAY09
Příbramský meteorit vynesl české vědce na špičku světové astronomie
iHNed.cz -
"Nedokázali jsme si jev vysvětlit, až ráno jsme se z rozhlasu dozvěděli, že na území Čech spadl meteorit." "Bolid byl jasný asi jako stowattová žárovka (more) ...
iHNed.cz -
"Nedokázali jsme si jev vysvětlit, až ráno jsme se z rozhlasu dozvěděli, že na území Čech spadl meteorit." "Bolid byl jasný asi jako stowattová žárovka (more) ...
24 May 2009
Mars Impact Crater Indicates Ancient Mars Climate 23MAY09
Opportunity Reveals Long-time Water, Winds at Victoria
A sizable collaboration of researchers has unveiled an enormous set of data from NASA’s Opportunity rover today — data that testify to the rover’s lucky longevity, and paint a picture of climate events that have shaped Victoria Crater, shown in this NASA/JPL-Caltech image. The climate history is vast and compelling, including dramatic floods and terrain-shaping winds spanning [...]
Universe Today - May 22 5:47 AM
Mars was windy, wet and wild in ancient times
Washington, May 22 : The instruments aboard the Rover Opportunity, which are studying the Victoria Crater on Mars, has revealed more evidence of the red planet's windy, wet and wild past.
New Kerala - May 22 2:33 AM
A sizable collaboration of researchers has unveiled an enormous set of data from NASA’s Opportunity rover today — data that testify to the rover’s lucky longevity, and paint a picture of climate events that have shaped Victoria Crater, shown in this NASA/JPL-Caltech image. The climate history is vast and compelling, including dramatic floods and terrain-shaping winds spanning [...]
Universe Today - May 22 5:47 AM
Mars was windy, wet and wild in ancient times
Washington, May 22 : The instruments aboard the Rover Opportunity, which are studying the Victoria Crater on Mars, has revealed more evidence of the red planet's windy, wet and wild past.
New Kerala - May 22 2:33 AM
23 May 2009
Morocco To Hold Meteorite Exposition 22MAY09
Expo: Meteorites of Morocco, a Heavenly Heritage
For the first time in Morocco; an exhibition of meteorites will take place at the Amazigh Heritage Museum of Agadir (Morocco) from Tuesday June 2 to Friday 12 June 2009.
The exhibition will be led by a specialist who will answer your questions and with samples to touch. This event is organized by the Scientific and Cultural Club Ibn Zohr (C.S.C.I.Z.) and the laboratory of Petrology, Mineralogy and materials of Ibn Zohr University (L.P.M.M.).
All lovers of these space random travelers that are meteors (Amateurs, Private collectors and professional from the scientific community) are invited to gather in this magical place in the center of Agadir city.
You will be able to admire many meteorites owned by the L.P.M.M. laboratory; understand the phenomenon of meteorites from their fall to their collection in the desert and learn how to distinguish between Chondrites, Achondrites, and Iron meteorites.
For any further information please contact:
Prof. Ibhi Abderrahmane
Laboratoire de Pétrologie, Métallogénie et Matériaux
Faculté des Sciences, Agadir
Université Ibn Zohr
Tèl : 0528 23 58 60
GSM : O667 34 04 27
Fax : 0528 22 01 00
For the first time in Morocco; an exhibition of meteorites will take place at the Amazigh Heritage Museum of Agadir (Morocco) from Tuesday June 2 to Friday 12 June 2009.
The exhibition will be led by a specialist who will answer your questions and with samples to touch. This event is organized by the Scientific and Cultural Club Ibn Zohr (C.S.C.I.Z.) and the laboratory of Petrology, Mineralogy and materials of Ibn Zohr University (L.P.M.M.).
All lovers of these space random travelers that are meteors (Amateurs, Private collectors and professional from the scientific community) are invited to gather in this magical place in the center of Agadir city.
You will be able to admire many meteorites owned by the L.P.M.M. laboratory; understand the phenomenon of meteorites from their fall to their collection in the desert and learn how to distinguish between Chondrites, Achondrites, and Iron meteorites.
For any further information please contact:
Prof. Ibhi Abderrahmane
Laboratoire de Pétrologie, Métallogénie et Matériaux
Faculté des Sciences, Agadir
Université Ibn Zohr
Tèl : 0528 23 58 60
GSM : O667 34 04 27
Fax : 0528 22 01 00
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New insights from Canadian meteorites 22MAY09
American Geophysical Union
2009 Joint Assembly
The Meeting of the Americas
24–27 May 2009
Toronto, Ontario, Canada
http://www.agu.org/meetings/ja09/
Press conference on "New insights from Canadian meteorites" to be held on Sunday, 24 May at 1400h.
http://www.eurekalert.org/pub_releases/2009-05/agu-aja052109.php
New insights from Canadian meteorites
Meteorites, being rocks from space, are solid samples of places in the Solar System to which we cannot easily go. The study of their physical and mineralogical characteristics provides insights into the diversity of processes involved in their origin. Likewise, the conditions under which they fall to Earth provide links to their asteroid or planetary parent bodies. Speakers will discuss new results regarding detection of organic molecules important for life in the unique Tagish Lake, B.C. meteorite (Herd), special conditions of formation of the 1000-year old Whitecourt, Alberta impact crater (Kofman), and the spectacular November 20, 2008 fireball that resulted in the fall of the Buzzard Coulee, Saskatchewan meteorite (Hildebrand).
Participants:
Alan Hildebrand Canada Research Chair in Planetary Science, Coordinator of the Canadian Fireball Reporting Centre, Department of Geoscience, University of Calgary, Calgary, Alberta, Canada;
Randolf Kofman Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada;
Christopher Herd Associate Professor, Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada.
Sessions: MA11B, MA12A, MA13A, MA13C
2009 Joint Assembly
The Meeting of the Americas
24–27 May 2009
Toronto, Ontario, Canada
http://www.agu.org/meetings/ja09/
Press conference on "New insights from Canadian meteorites" to be held on Sunday, 24 May at 1400h.
http://www.eurekalert.org/pub_releases/2009-05/agu-aja052109.php
New insights from Canadian meteorites
Meteorites, being rocks from space, are solid samples of places in the Solar System to which we cannot easily go. The study of their physical and mineralogical characteristics provides insights into the diversity of processes involved in their origin. Likewise, the conditions under which they fall to Earth provide links to their asteroid or planetary parent bodies. Speakers will discuss new results regarding detection of organic molecules important for life in the unique Tagish Lake, B.C. meteorite (Herd), special conditions of formation of the 1000-year old Whitecourt, Alberta impact crater (Kofman), and the spectacular November 20, 2008 fireball that resulted in the fall of the Buzzard Coulee, Saskatchewan meteorite (Hildebrand).
Participants:
Alan Hildebrand Canada Research Chair in Planetary Science, Coordinator of the Canadian Fireball Reporting Centre, Department of Geoscience, University of Calgary, Calgary, Alberta, Canada;
Randolf Kofman Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada;
Christopher Herd Associate Professor, Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada.
Sessions: MA11B, MA12A, MA13A, MA13C
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22 May 2009
Meteorites: An Intro to Cosmic Geology 22MAY09
Cosmic Geology Lands in Berthoud
Berthoud Recorder - 5 hours ago
Matt Morgan`s show entitled, “Meteorites: An Intro to Cosmic Geology” gave fascinating highlights of some of the most notable meteorite falls, mainly focused on those (more)...
Berthoud Recorder - 5 hours ago
Matt Morgan`s show entitled, “Meteorites: An Intro to Cosmic Geology” gave fascinating highlights of some of the most notable meteorite falls, mainly focused on those (more)...
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India- Press Reports Meteorite Fall 21MAY09
Two meteorites found in Muzaffarnagar
The Times of India
21 May 2009, 1733 hrs IST, PTI
http://timesofindia.indiatimes.com/India/Two-meteorites-found-in-Muzaffarnagar/articleshow/4560916.cms
MUZAFFARNAGAR, Uttar Pradesh: A Karimpur villager in the district was alarmed when two hot embers fell down from the sky in his compound after rainfall.
An expert later said the two pieces found in Shyambir's house compound are meteorites and could be part of a bigger meteor that might have exploded while rushing down the earth's atmosphere.
"Two small meteorites which fell in the house compound were hot," Shyambir claimed. The pieces, which were found yesterday, weigh about 250 gm and 100 gm, he said.
A professor in the field of astronomy and celestial bodies, Deepak Sharma, said the two pieces are believed to be parts of a bigger meteor which must have exploded.
According to villagers, the pieces fell down after rainfall in the area yesterday.
Some years ago, a big meteorite had fallen down at Kasoli village in the district, weighing about seven kg.
The Times of India
21 May 2009, 1733 hrs IST, PTI
http://timesofindia.indiatimes.com/India/Two-meteorites-found-in-Muzaffarnagar/articleshow/4560916.cms
MUZAFFARNAGAR, Uttar Pradesh: A Karimpur villager in the district was alarmed when two hot embers fell down from the sky in his compound after rainfall.
An expert later said the two pieces found in Shyambir's house compound are meteorites and could be part of a bigger meteor that might have exploded while rushing down the earth's atmosphere.
"Two small meteorites which fell in the house compound were hot," Shyambir claimed. The pieces, which were found yesterday, weigh about 250 gm and 100 gm, he said.
A professor in the field of astronomy and celestial bodies, Deepak Sharma, said the two pieces are believed to be parts of a bigger meteor which must have exploded.
According to villagers, the pieces fell down after rainfall in the area yesterday.
Some years ago, a big meteorite had fallen down at Kasoli village in the district, weighing about seven kg.
Posted by
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Indian Meteorite News,
Karimpur Muzaffarnagar India meteorite fall 20MAY09?,
meteorite fall
21 May 2009
ASTEROIDS MAY HAVE ACCELERATED LIFE ON EARTH 21MAY09
NASA STUDY SHOWS ASTEROIDS MAY HAVE ACCELERATED LIFE ON EARTH
20MAY09 WASHINGTON --
A NASA-funded study indicates that an intense asteroid bombardment nearly 4 billion years ago may not have sterilized the early Earth as completely as previously thought. The asteroids, some the size of Kansas, possibly even provided a boost for early life. The study focused on a particularly cataclysmic occurrence known as the Late Heavy Bombardment, or LHB.
This event occurred approximately 3.9 billion years ago and lasted 20 to 200 million years. In a letter published in the May 21 issue of Nature magazine titled "Microbial Habitability of the Hadean Earth during the Late Heavy Bombardment," Oleg Abramov and Stephen J. Mojzsis, astrobiologists at the University of Colorado's Department of Geological Sciences, report on the results of a computer modeling project designed to study the heating of Earth by the bombardment.
Results from their project show that while the Late Heavy Bombardment might have generated enough heat to sterilize Earth's surface, microbial life in subsurface and underwater environments almost certainly would have survived.
"Exactly when life originated on Earth is a hotly debated topic," said Michael H. New, the astrobiology discipline scientist and manager of the Exobiology and Evolutionary Biology Program at NASA Headquarters in Washington.
"These findings are significant because they indicate that if life had begun before the LHB or some time prior to 4 billion years ago, it could have survived in limited refuges and then expanded to fill our world."
"Our new results point to the possibility life could have emerged about the same time that evidence for our planet's oceans first appears," said Mojzsis, principal investigator of the project.
A growing scientific consensus is that during our solar system's formation, planetary bodies were pummeled by debris throughout the Late Heavy Bombardment. A visual record of the event is preserved in the form of the scarred face of our moon. On Earth, all traces of the bombardment appear to have been erased by rock recycling forces like weathering, volcanoes or other conditions that cause the crust to move or change. Surface habitats for microbial life on early Earth would have been destroyed repeatedly by the bombardment.
However, at the same time, impacts could have created subsurface habitats for life, such as extensive networks of cracks or even hydrothermal vents. Any existing microbial life on Earth could have found refuge in these habitats. If life had not yet emerged on Earth by the time of the bombardment, these new subsurface environments could have been the place where terrestrial life emerged.
"Even under the most extreme conditions we imposed on our model, the bombardment could not have sterilized Earth completely," said Abramov, lead author of the paper. "Our results are in line with the scientific consensus that hyperthermophilic, or 'heat-loving,' microbes could have been the earliest life forms on Earth, or survivors from an even more ancient biosphere.
The results also support the potential for the persistence of microbial biospheres on other planetary bodies whose surfaces were reworked by the bombardment, including Mars." NASA's Astrobiology Program's Exobiology and Evolutionary Biology Program and the NASA Astrobiology Institute at NASA's Ames Research Center at Moffett Field, Calif., through its support of NASA's Postdoctoral Program, provided funding for this research.
The Astrobiology Program supports research into the origin, evolution, distribution and future of life on Earth and the potential for life elsewhere.
For more information about NASA's astrobiology activities, visit:
May 20, 2009
Dwayne Brown Headquarters, Washington 202-358-1726 dwayne.c.brown@nasa.gov
Jim Scott University of Colorado, Boulder 303-492-3114 jim.scott@colorado.edu
RELEASE: 09-111
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20 May 2009
Ancient tsunami 'hit New York' 20MAY09
Ancient tsunami 'hit New York'
By Molly Bentley, Science reporter
BBC NEWS 3MAY09
A huge wave crashed into the New York City region 2,300 years ago, dumping sediment and shells across Long Island and New Jersey and casting wood debris far up the Hudson River.
The scenario, proposed by scientists, is undergoing further examination to verify radiocarbon dates and to rule out other causes of the upheaval. ...
By Molly Bentley, Science reporter
BBC NEWS 3MAY09
A huge wave crashed into the New York City region 2,300 years ago, dumping sediment and shells across Long Island and New Jersey and casting wood debris far up the Hudson River.
The scenario, proposed by scientists, is undergoing further examination to verify radiocarbon dates and to rule out other causes of the upheaval. ...
Oldest Surface on Earth Discovered 20MAY09
Oldest Surface on Earth Discovered
(Live Science)
A new study of ancient "desert pavement" in Israel's Negev Desert finds a vast region that's been sitting there exposed, pretty much as-is, for about 1.8 million years, making it the oldest known vast expanse of surface area. more...
(Live Science)
A new study of ancient "desert pavement" in Israel's Negev Desert finds a vast region that's been sitting there exposed, pretty much as-is, for about 1.8 million years, making it the oldest known vast expanse of surface area. more...
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Describen el primer cráter elíptico por impacto de meteorito 19MAY09
En Australia
Describen el primer cráter elíptico por impacto de meteorito
MADRID, 5 May. (EUROPA PRESS) - Prácticamente todos los cráteres por impactos de meteorito en la Tierra son circulares. Formaciones alargadas sólo pueden producirse con impactos producidos con un ángulo menor a 12 grados sobre el horizonte.
Un equipo de geólogos ha descrito en Australia el primer cráter de estas características, que puede proporcionar valiosa información sobre los mecanismos de formación de cráteres con pequeños ángulos de impacto.
El diámetro del cráter Matt Wilson, localizado en el Territorio del Norte (Australia) mide 7,5 por 6,3 kilómetros, con un eje alrgado en dirección noreste-suroeste. La superficie del interior del cráter muestra una acumulación de placas apiladas dentro de una elevación central, lo que indica que el material se transportó en dirección suroeste.
Esto se explica debido al vestigio de velocidad horizontal transferida por el meteorito a las rocas contra las que que impactó. La estructura Matt Wilson proporciona evidencias respecto a la utilidad de las asimetrías estructurales como herramienta de diagnóstico para inferir la dirección del impacto.
El estudio, realizado por Thomas Kekmann y Michael H.Poelchau, se publica en la edición de mayo de la revista Geogology, informa ScienceDaily.
http://www.europapress.es/ciencia-00298/noticia-describen-primer-crater-eliptico-impacto-meteorito-20090505172617.html
Describen el primer cráter elíptico por impacto de meteorito
MADRID, 5 May. (EUROPA PRESS) - Prácticamente todos los cráteres por impactos de meteorito en la Tierra son circulares. Formaciones alargadas sólo pueden producirse con impactos producidos con un ángulo menor a 12 grados sobre el horizonte.
Un equipo de geólogos ha descrito en Australia el primer cráter de estas características, que puede proporcionar valiosa información sobre los mecanismos de formación de cráteres con pequeños ángulos de impacto.
El diámetro del cráter Matt Wilson, localizado en el Territorio del Norte (Australia) mide 7,5 por 6,3 kilómetros, con un eje alrgado en dirección noreste-suroeste. La superficie del interior del cráter muestra una acumulación de placas apiladas dentro de una elevación central, lo que indica que el material se transportó en dirección suroeste.
Esto se explica debido al vestigio de velocidad horizontal transferida por el meteorito a las rocas contra las que que impactó. La estructura Matt Wilson proporciona evidencias respecto a la utilidad de las asimetrías estructurales como herramienta de diagnóstico para inferir la dirección del impacto.
El estudio, realizado por Thomas Kekmann y Michael H.Poelchau, se publica en la edición de mayo de la revista Geogology, informa ScienceDaily.
http://www.europapress.es/ciencia-00298/noticia-describen-primer-crater-eliptico-impacto-meteorito-20090505172617.html
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19 May 2009
Mass Extinctions- Medea Hypothesis 19MAY09
Peter Ward on mass extinctions
http://www.ted.com/index.php/talks/peter_ward_on_mass_extinctions.htmlhttp://www.youtube.com/watch?v=3lYN_lXU9PA
Speakers Peter Ward: Paleontologist
http://www.ted.com/index.php/speakers/peter_ward.html
The Medea Hypothesis: Is Life on Earth Ultimately Self-Destructive? by Peter Ward
http://press.princeton.edu/titles/8855.htmlhttp://press.princeton.edu/titles/8855.html#TOC“
Using the latest discoveries from the geological record, he argues that life might be its own worst enemy.”
“According to the Medea hypothesis, it does. Ward demonstrates that all but one of the mass extinctions that have struck Earth were caused by life itself. He looks at our planet's history in a new way, revealing an Earth that is witnessing an alarming decline of diversity and biomass--a decline brought on by life's own "biocidal" tendencies.”
http://www.ted.com/index.php/talks/peter_ward_on_mass_extinctions.htmlhttp://www.youtube.com/watch?v=3lYN_lXU9PA
Speakers Peter Ward: Paleontologist
http://www.ted.com/index.php/speakers/peter_ward.html
The Medea Hypothesis: Is Life on Earth Ultimately Self-Destructive? by Peter Ward
http://press.princeton.edu/titles/8855.htmlhttp://press.princeton.edu/titles/8855.html#TOC“
Using the latest discoveries from the geological record, he argues that life might be its own worst enemy.”
“According to the Medea hypothesis, it does. Ward demonstrates that all but one of the mass extinctions that have struck Earth were caused by life itself. He looks at our planet's history in a new way, revealing an Earth that is witnessing an alarming decline of diversity and biomass--a decline brought on by life's own "biocidal" tendencies.”
Posted by
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Labels:
evolution,
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Did a Nickel Famine Trigger the "Great Oxidation Event"? 19MAY09
Did a Nickel Famine Trigger the "Great Oxidation Event"?
Carnegie Institution of Washington
Contact:Dominic Papineau, 202-478-8908
April 8, 2009
Contact:Dominic Papineau, 202-478-8908
April 8, 2009
Washington, D.C. -- The Earth's original atmosphere held very little oxygen. This began to change around 2.4 billion years ago when oxygen levels increased dramatically during what scientists call the "Great Oxidation Event."
The cause of this event has puzzled scientists, but researchers writing in Nature[*] have found indications in ancient sedimentary rocks that it may have been linked to a drop in the level of dissolved nickel in seawater.
"The Great Oxidation Event is what irreversibly changed surface environments on Earth and ultimately made advanced life possible," says research team member Dominic Papineau of the Carnegie Institution's Geophysical Laboratory. "It was a major turning point in the evolution of our planet,and we are getting closer to understanding how it occurred."
The researchers, led by Kurt Konhauser of the University of Alberta in Edmonton, analyzed the trace element composition of sedimentary rocks known as banded-iron formations, or BIFs, from dozens of different localities around the world, ranging in age from 3,800 to 550 million years.
Banded iron formations are unique, water-laid deposits often found in extremely old rock strata that formed before the atmosphere or oceans contained abundant oxygen. As their name implies, they are made of alternating bands of iron and silicate minerals. They also contain minor amounts of nickel and other trace elements.
Nickel exists in today's oceans in trace amounts, but was up to 400 times more abundant in the Earth's primordial oceans. Methane-producing microorganisms, called methanogens, thrive in such environments, and the methane they released to the atmosphere might have prevented the buildup of oxygen gas, which would have reacted with the methane to produce carbon dioxide and water.
A drop in nickel concentration would have led to a"nickel famine" for the methanogens, who rely on nickel-based enzymes for key metabolic processes. Algae and other organisms that release oxygen during photosynthesis use different enzymes, and so would have been less affected by the nickel famine. As a result, atmospheric methane would have declined, and the conditions for the rise of oxygen would have been set in place.The researchers found that nickel levels in the BIFs began dropping around 2.7 billion years ago and by 2.5 billion years ago was about half its earlier value.
"The timing fits very well. The drop in nickel could have set the stage for the Great Oxidation Event," says Papineau. "And from what we know about living methanogens, lower levels of nickel would have severely cut back methane production."What caused the drop in nickel? The researchers point to geologic changes that were occurring during the interval. During earlier phases of the Earth's history, while its mantle was extremely hot, lavas from volcanic eruptions would have been relatively high in nickel. Erosion would have washed the nickel into the sea, keeping levels high. But as the mantle cooled, and the chemistry of lavas changed, volcanoes spewed out less nickel, and less would have found its way to the sea."The nickel connection was not something anyone had considered before," says Papineau. "It's just a trace element in seawater, but our study indicates that it may have had a huge impact on the Earth's environment and on the history of life."
[*] Kurt O. Konhauser, Ernesto Pecoits, Stefan V. Lalonde, Dominic Papineau,Euan G. Nisbet, Mark E. Barley, Nicholas T. Arndt, Kevin Zahnle & Balz S.Kamber, Oceanic nickel depletion and a methanogen famine before the Great Oxidation Event, scheduled for publication in Nature on 09 April, 2009.
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Asteroid Impact Prediction 19MAY09
Can We Predict When An Asteroid Will Impact Earth
SpaceDaily
by Staff Writers Bonn, Germany (SPX)
May 19, 2009
Objects with orbits that bring them near to Earth are potential killers. ...
SpaceDaily
by Staff Writers Bonn, Germany (SPX)
May 19, 2009
Objects with orbits that bring them near to Earth are potential killers. ...
Latest Worldwide Meteor/Meteorite News 19MAY09
Possible Meteorite-NOT Found in Field
FOX 4 News Dallas - Fort Worth
Mon, 18 May 2009 11:05 AM PDT
Scientists have visited a field in Somervell County to see if a mysterious rock is indeed a meteorite. ...
Collector pays $50,000 for a 5-pound rock
Chicago Sun-Times
Mon, 18 May 2009 07:30 AM PDT
The Garza stone has a new home. The five-pound meteorite that crashed into a Park Forest home in 2003 was bought by a private collector for $50,787.50 Sunday during an auction by Dallas-based Heritage Auctions. David Herskowitz, director of natural history at Heritage, says it's the Garza's provenance that makes it exceptional. "The added value of this meteorite is that it hit a man-made ...
「地球外生命体を光で探す」新手法
(New Method for Detecting Extraterrestrial Life)
Wired Vision
この説の証拠としては、太陽系形成初期からあまり変質していないと考えられているマーチソン隕石に地球上に存在していないアミノ酸が検出され、このアミノ酸がL体が ...
FOX 4 News Dallas - Fort Worth
Mon, 18 May 2009 11:05 AM PDT
Scientists have visited a field in Somervell County to see if a mysterious rock is indeed a meteorite. ...
Collector pays $50,000 for a 5-pound rock
Chicago Sun-Times
Mon, 18 May 2009 07:30 AM PDT
The Garza stone has a new home. The five-pound meteorite that crashed into a Park Forest home in 2003 was bought by a private collector for $50,787.50 Sunday during an auction by Dallas-based Heritage Auctions. David Herskowitz, director of natural history at Heritage, says it's the Garza's provenance that makes it exceptional. "The added value of this meteorite is that it hit a man-made ...
「地球外生命体を光で探す」新手法
(New Method for Detecting Extraterrestrial Life)
Wired Vision
この説の証拠としては、太陽系形成初期からあまり変質していないと考えられているマーチソン隕石に地球上に存在していないアミノ酸が検出され、このアミノ酸がL体が ...
18 May 2009
Swiss Geologists Return From Oman with Meteorites 18MAY2009
Searching for Meteorites in the Deserts of Oman
By Simon Mitton
Astrobiology Magazine --May 18, 2009
Rub Al-Khali desert close to the border to Saudi Arabia.
The team checked out flat area between the 100-metre high dunes and the salt marsh in the foreground, making several meteorite finds in this location. ...
http://www.astrobio.net/exclusive/3127/searching-for-meteorites-in-the-deserts-of-omanRelated Articles:
Note: Meteors, Comets and Asteroids
Posted by
Lunar Meteorite * Hunter
at
11:00 pm
Labels:
Dr. Beda Hofmann,
Oman,
Oman Meteorite News,
Swiss Oman Meteorite Research 2009
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