WASHINGTON (Reuters) - Asteroids crashing into Earth have virtually wiped out life not once but at least twice, scientists have reported.
An asteroid or comet roughly the same size as the one that wiped out the dinosaurs 65 million years ago did even worse damage 250 million years ago, experts found in a report published in Friday's issue of the journal Science.
The evidence comes from space gases trapped in little carbon spheres called Buckyballs in ancient layers of sediment. They show the Permian extinction event, during which most species on the planet disappeared, started with a cosmic collision.
"The impact ... releases an amount of energy that is basically about 1 million times the largest earthquake recorded during the last century," Robert Poreda, associate professor of earth and environmental sciences at the University of Rochester in New York, who worked on the study, said in a statement.
The comet or asteroid would have to have been 4 to 8 miles (6.5 to 13 kms) across. The jolt roused volcanoes, which buried huge areas in lava and sent up ash to join the dust from the explosion to plunge the world into centuries of unnatural dark and cold.
Trilobites -- strange, ****roach-like creatures that once ruled the planet -- died out completely, all 15,000 species of them. Ninety percent of all marine creatures and 70 percent of land vertebrates went extinct.
Want to learn more? http://www.reuters.com/news_article.jhtml?type=world&Repository=WORLD_REP&RepositoryStoryID=%2Fnews%2FIDS%2FWorld%2FOUKWD-SCIENCE-ASTEROID_TXT.XML
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One door closed is one door opened
One more memory fades away
Such grand dreams we all have chosen
We lost our innocence along the way
- Rose Bygrave, "Innocence"
PsychoticIckyThing.Com
An asteroid or comet roughly the same size as the one that wiped out the dinosaurs 65 million years ago did even worse damage 250 million years ago, experts found in a report published in Friday's issue of the journal Science.
The evidence comes from space gases trapped in little carbon spheres called Buckyballs in ancient layers of sediment. They show the Permian extinction event, during which most species on the planet disappeared, started with a cosmic collision.
"The impact ... releases an amount of energy that is basically about 1 million times the largest earthquake recorded during the last century," Robert Poreda, associate professor of earth and environmental sciences at the University of Rochester in New York, who worked on the study, said in a statement.
The comet or asteroid would have to have been 4 to 8 miles (6.5 to 13 kms) across. The jolt roused volcanoes, which buried huge areas in lava and sent up ash to join the dust from the explosion to plunge the world into centuries of unnatural dark and cold.
Trilobites -- strange, ****roach-like creatures that once ruled the planet -- died out completely, all 15,000 species of them. Ninety percent of all marine creatures and 70 percent of land vertebrates went extinct.
Want to learn more? http://www.reuters.com/news_article.jhtml?type=world&Repository=WORLD_REP&RepositoryStoryID=%2Fnews%2FIDS%2FWorld%2FOUKWD-SCIENCE-ASTEROID_TXT.XML
------------------
One door closed is one door opened
One more memory fades away
Such grand dreams we all have chosen
We lost our innocence along the way
- Rose Bygrave, "Innocence"
PsychoticIckyThing.Com
