tangent4ronpaul
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Mega volcanoes responsible for mass extinctions on Earth?
Massive volcanic eruptions may have led to the extermination of half of Earth's species some 200 million years ago, a new study suggests.
The release of gases from giant eruptions caused climate change that led to the End-Triassic Extinction, the widespread loss of land and sea species that made way for the rise of the dinosaurs, the research says. The new study, published Thursday, March 21, in the journal Science, shows that a set of major eruptions spanning from what is now New Jersey to Morocco occurred very close to the time of the extinction.
Scientists suspected previously that such volcanic activity and the resultant climate change were responsible for this major extinction and at least four others. But researchers weren't able to constrain the dates of the eruptions and extinctions well enough to prove the hypothesis. The new study, however, dates the End-Triassic Extinction to 201.56 million years ago, the same time the volcanoes were blowing their tops.
The eruptions, known as the Central Atlantic Magmatic Province, began when the land on Earth was part of one giant supercontinent called Pangaea. They lasted more than 600,000 years and created a rift that became the Atlantic Ocean. The researchers studied lava from these flows in modern-day Nova Scotia, Morocco and New Jersey. [Big Blasts: History's 10 Most Destructive Volcanoes]
The previous dates for these eruptions had error margins of 1 million to 3 million years, but this study decreases those numbers by an order of magnitude, lead author Terrence Blackburn, a geologist at the Carnegie Institution for Science, told LiveScience.
The results showed that the oldest massive eruptions were in Morocco, followed by the ones in Nova Scotia 3,000 years later and then those in New Jersey another 10,000 years after that. Animal and plant fossils, along with pollen and spores from the Triassic era, can be found in sediment layers underneath the lava flows, but not in layers above them. This suggests the eruptions wiped out those species. The organisms that went extinct include eel-like fish called conodonts, early crocodile species, tree lizards and broad-leaved plants.
Read more: http://www.foxnews.com/science/2013...have-killed-half-earth-species/#ixzz2OMDy5a2e
Asteroid Killed Off Dinosaurs? New Study Suggests Comet Instead Caused Extinction Event
http://www.huffingtonpost.com/2013/03/23/asteroid-killed-dinosaurs-comet-extinction_n_2937296.html
The rocky object that wiped out the dinosaurs 65 million years ago may have been a comet, rather than an asteroid, scientists say.
The 112-mile (180 kilometers) Chicxulub crater in Mexico was made by the impact that caused the extinction of dinosaurs and about 70 percent of all species on Earth, many scientists believe. A new study suggests the crater was probably blasted out by a faster, smaller object than previously thought, according to research presented this week at the 44th Lunar and Planetary Science Conference in The Woodlands, Texas.
Evidence of the space rock's impact comes from a worldwide layer of sediments containing high levels of the element iridium, dubbed the Cretaceous-Paleogene (K-Pg) boundary, which could not have occurred on Earth naturally.
The new research suggests the often-cited iridium values are incorrect, however. The scientists compared these values with levels of osmium, another element delivered by the impact.
Their calculations suggested the space rock generated less debris than previously thought, implying the space rock was a smaller object. In order for the smaller rock to have created the giant Chicxulub crater, it had to have been going exceedingly fast, the researchers concluded.
"How do we get something that has enough energy to generate that size of crater, but has much less rocky material? That brings us to comets," study author Jason Moore, a paleoecologist at Dartmouth College in New Hampshire, told BBC News. [Meteor Crater: Experience an Ancient Impact]
Comets are balls of ice, dust and rocky particles that are distinguished from asteroids by their highly eccentric orbits and thin, fuzzy atmospheres, called comas or tails. The Chicxulub impact is more compatible with a long-period comet, the results indicated, which can take hundreds, thousands or sometimes millions of years to orbit the sun once.
It is possible that a rapidly moving asteroid could have caused the Chicxulub impact crater, the researchers said, but the fastest-moving objects that have been observed are mostly comets.
"I think it's some very interesting work," physicist Brandon Johnson of Purdue University, who was not involved in the research, told LiveScience. If the impact were in fact a comet, "it could change things quite a bit," he said – a comet would have rained down a lot more material than an asteroid.
But the findings are debatable: "There's a possibility that a lot of the impacted material could have been ejected at escape velocity, so we couldn't find it on Earth," Johnson said. This means the remnants of the impact could be just a fraction of the mass of the space rock, suggesting it could still have been an asteroid.
Geologist Gareth Collins of Imperial College London, U.K., agreed. "Geochemistry tells you — quite accurately — only the mass of meteoritic material that is distributed globally, not the total mass of the impactor," Collins told BBC News, adding, "To estimate the latter, one needs to know what fraction of the impactor was distributed globally, as opposed to being ejected to space or landing close to the crater."
The researchers suggest that 75 percent of the space rock's mass was distributed on Earth, Collins said, but he contends that it could have been less than 20 percent — an amount that could have come from a larger and slower asteroid. In response, the researchers point to studies that suggest the object lost an amount of mass consistent with their findings.
But geophysicist Jay Melosh, also of Purdue University, remains skeptical. "The evidence that they have for a high velocity impact is marginally positive. However, the probability that that high velocity impact is a comet is very low," he said, adding that it's much more likely to be a faster-than-usual asteroid.
Asteroid headed toward Earth? 'Pray,' NASA advises
http://www.foxnews.com/science/2013/03/20/asteroid-threat-earthly-budgets/?intcmp=trending
In the wake of last month's meteor strike in Russia and a close asteroid flyby on the same day, members of Congress asked NASA, White House and Air Force officials what they're doing to combat the threat of near-Earth asteroids during a hearing Tuesday on Capitol Hill.
"The answer to you is, 'if it's coming in three weeks, pray,'" space agency chief Charles Bolden said, in response to Rep. Bill Posey (R-Fla.), who asked what NASA would do if a large asteroid headed on a collision course with Earth was discovered today with only three weeks before impact.
"The reason I can't do anything in the next three weeks is because for decades we have put it off."
By and large, the experts stressed that the two space rock events were a coincidence and that the chance of a catastrophic asteroid impact to Earth any time soon is remote. On Feb. 15, a surprise meteor exploded in the sky over Russia's Ural Mountains, just hours before the 150-foot-wide asteroid 2012 DA14 flew close by Earth in a pass that had been predicted beforehand by scientists.
"The odds of a near-Earth object strike causing massive causalities and destruction of infrastructure are very small, but the potential consequences of such an event are so large that it makes sense to take the risk seriously," John Holdren, science advisor to President Barack Obama, told the Science, Space and Technology Committee of the U.S. House of Representatives.
Still, Rep. Lamar Smith (R-Texas), chairman of the Science, Space and Technology Committee, said it was "not reassuring" to learn that NASA has so far detected only about 10 percent of the near-Earth objects that are wider than 87 miles across. Holdren estimated that there may be hundreds of thousands of such objects within one-third the distance from Earth to the sun that remain unknown. [Meteor Streaks Over Russia, Explodes (Photos)]
In 2005, Congress directed NASA to detect, track and characterize 90 percent of these space rocks —those near-Earth asteroids larger than 87 miles. Bolden said today that NASA was unlikely to meet that deadline given its current budget.
"Our estimate right now is at the present budget levels it will be 2030 before we're able to reach the 90 percent level as prescribed by Congress," Bolden said.
Bolden criticized the lawmakers for slowing NASA down through budget cuts. "You all told us to do something, and between the administration and the Congress, the bottom line is the funding did not come," Bolden said.
Furthermore, he said the goal of finding a way to respond to asteroid threats has been repeatedly put off by lawmakers who cite a lack of money.
Budget concerns also hamper the military's ability to monitor near-Earth objects and other space threats, such as orbital debris (defunct satellites and spent rocket stages that litter Earth orbit).
"We are clearly less capable under sequestration," Gen. William Shelton, the current commander of the U.S. Air Force Space Command, told the committee. He said that any further budget cuts could have dire consequences.
"Our dependence on space, not only for our way of life but also for military operations, is very high, so we would sacrifice that," Shelton said.
[Can you say RAPID CLIMATE CHANGE? - I thought you could...]
Meteor captured on camera in US
http://www.telegraph.co.uk/science/space/9949771/Meteor-captured-on-camera-in-US.html
Nasa has said that the flash of light that streaked across the sky over the US East Coast and was captured on security cameras appeared to be a "single meteor event".
A security camera above a car yard in Seaford, Delaware, and another in Maryland captured footage of what appeared to be a meteor travelling across the skyline late on Friday.
Nasa said that the flash of light that streaked across the sky over the US East Coast appeared to be a "single meteor event".
Bill Cooke of Nasa's Meteoroid Environmental Office said the meteor was widely seen, with more than 350 reports on the website of the American Meteor Society alone.
The sky flash was spotted as far south as Florida and as far north as New England, the newspaper USA Today reported.
Derrick Pitts, chief astronomer at Philadelphia's Franklin Institute, agreed that the sightings had all the hallmarks of a "fireball."
-t
Massive volcanic eruptions may have led to the extermination of half of Earth's species some 200 million years ago, a new study suggests.
The release of gases from giant eruptions caused climate change that led to the End-Triassic Extinction, the widespread loss of land and sea species that made way for the rise of the dinosaurs, the research says. The new study, published Thursday, March 21, in the journal Science, shows that a set of major eruptions spanning from what is now New Jersey to Morocco occurred very close to the time of the extinction.
Scientists suspected previously that such volcanic activity and the resultant climate change were responsible for this major extinction and at least four others. But researchers weren't able to constrain the dates of the eruptions and extinctions well enough to prove the hypothesis. The new study, however, dates the End-Triassic Extinction to 201.56 million years ago, the same time the volcanoes were blowing their tops.
The eruptions, known as the Central Atlantic Magmatic Province, began when the land on Earth was part of one giant supercontinent called Pangaea. They lasted more than 600,000 years and created a rift that became the Atlantic Ocean. The researchers studied lava from these flows in modern-day Nova Scotia, Morocco and New Jersey. [Big Blasts: History's 10 Most Destructive Volcanoes]
The previous dates for these eruptions had error margins of 1 million to 3 million years, but this study decreases those numbers by an order of magnitude, lead author Terrence Blackburn, a geologist at the Carnegie Institution for Science, told LiveScience.
The results showed that the oldest massive eruptions were in Morocco, followed by the ones in Nova Scotia 3,000 years later and then those in New Jersey another 10,000 years after that. Animal and plant fossils, along with pollen and spores from the Triassic era, can be found in sediment layers underneath the lava flows, but not in layers above them. This suggests the eruptions wiped out those species. The organisms that went extinct include eel-like fish called conodonts, early crocodile species, tree lizards and broad-leaved plants.
Read more: http://www.foxnews.com/science/2013...have-killed-half-earth-species/#ixzz2OMDy5a2e
Asteroid Killed Off Dinosaurs? New Study Suggests Comet Instead Caused Extinction Event
http://www.huffingtonpost.com/2013/03/23/asteroid-killed-dinosaurs-comet-extinction_n_2937296.html
The rocky object that wiped out the dinosaurs 65 million years ago may have been a comet, rather than an asteroid, scientists say.
The 112-mile (180 kilometers) Chicxulub crater in Mexico was made by the impact that caused the extinction of dinosaurs and about 70 percent of all species on Earth, many scientists believe. A new study suggests the crater was probably blasted out by a faster, smaller object than previously thought, according to research presented this week at the 44th Lunar and Planetary Science Conference in The Woodlands, Texas.
Evidence of the space rock's impact comes from a worldwide layer of sediments containing high levels of the element iridium, dubbed the Cretaceous-Paleogene (K-Pg) boundary, which could not have occurred on Earth naturally.
The new research suggests the often-cited iridium values are incorrect, however. The scientists compared these values with levels of osmium, another element delivered by the impact.
Their calculations suggested the space rock generated less debris than previously thought, implying the space rock was a smaller object. In order for the smaller rock to have created the giant Chicxulub crater, it had to have been going exceedingly fast, the researchers concluded.
"How do we get something that has enough energy to generate that size of crater, but has much less rocky material? That brings us to comets," study author Jason Moore, a paleoecologist at Dartmouth College in New Hampshire, told BBC News. [Meteor Crater: Experience an Ancient Impact]
Comets are balls of ice, dust and rocky particles that are distinguished from asteroids by their highly eccentric orbits and thin, fuzzy atmospheres, called comas or tails. The Chicxulub impact is more compatible with a long-period comet, the results indicated, which can take hundreds, thousands or sometimes millions of years to orbit the sun once.
It is possible that a rapidly moving asteroid could have caused the Chicxulub impact crater, the researchers said, but the fastest-moving objects that have been observed are mostly comets.
"I think it's some very interesting work," physicist Brandon Johnson of Purdue University, who was not involved in the research, told LiveScience. If the impact were in fact a comet, "it could change things quite a bit," he said – a comet would have rained down a lot more material than an asteroid.
But the findings are debatable: "There's a possibility that a lot of the impacted material could have been ejected at escape velocity, so we couldn't find it on Earth," Johnson said. This means the remnants of the impact could be just a fraction of the mass of the space rock, suggesting it could still have been an asteroid.
Geologist Gareth Collins of Imperial College London, U.K., agreed. "Geochemistry tells you — quite accurately — only the mass of meteoritic material that is distributed globally, not the total mass of the impactor," Collins told BBC News, adding, "To estimate the latter, one needs to know what fraction of the impactor was distributed globally, as opposed to being ejected to space or landing close to the crater."
The researchers suggest that 75 percent of the space rock's mass was distributed on Earth, Collins said, but he contends that it could have been less than 20 percent — an amount that could have come from a larger and slower asteroid. In response, the researchers point to studies that suggest the object lost an amount of mass consistent with their findings.
But geophysicist Jay Melosh, also of Purdue University, remains skeptical. "The evidence that they have for a high velocity impact is marginally positive. However, the probability that that high velocity impact is a comet is very low," he said, adding that it's much more likely to be a faster-than-usual asteroid.
Asteroid headed toward Earth? 'Pray,' NASA advises
http://www.foxnews.com/science/2013/03/20/asteroid-threat-earthly-budgets/?intcmp=trending
In the wake of last month's meteor strike in Russia and a close asteroid flyby on the same day, members of Congress asked NASA, White House and Air Force officials what they're doing to combat the threat of near-Earth asteroids during a hearing Tuesday on Capitol Hill.
"The answer to you is, 'if it's coming in three weeks, pray,'" space agency chief Charles Bolden said, in response to Rep. Bill Posey (R-Fla.), who asked what NASA would do if a large asteroid headed on a collision course with Earth was discovered today with only three weeks before impact.
"The reason I can't do anything in the next three weeks is because for decades we have put it off."
By and large, the experts stressed that the two space rock events were a coincidence and that the chance of a catastrophic asteroid impact to Earth any time soon is remote. On Feb. 15, a surprise meteor exploded in the sky over Russia's Ural Mountains, just hours before the 150-foot-wide asteroid 2012 DA14 flew close by Earth in a pass that had been predicted beforehand by scientists.
"The odds of a near-Earth object strike causing massive causalities and destruction of infrastructure are very small, but the potential consequences of such an event are so large that it makes sense to take the risk seriously," John Holdren, science advisor to President Barack Obama, told the Science, Space and Technology Committee of the U.S. House of Representatives.
Still, Rep. Lamar Smith (R-Texas), chairman of the Science, Space and Technology Committee, said it was "not reassuring" to learn that NASA has so far detected only about 10 percent of the near-Earth objects that are wider than 87 miles across. Holdren estimated that there may be hundreds of thousands of such objects within one-third the distance from Earth to the sun that remain unknown. [Meteor Streaks Over Russia, Explodes (Photos)]
In 2005, Congress directed NASA to detect, track and characterize 90 percent of these space rocks —those near-Earth asteroids larger than 87 miles. Bolden said today that NASA was unlikely to meet that deadline given its current budget.
"Our estimate right now is at the present budget levels it will be 2030 before we're able to reach the 90 percent level as prescribed by Congress," Bolden said.
Bolden criticized the lawmakers for slowing NASA down through budget cuts. "You all told us to do something, and between the administration and the Congress, the bottom line is the funding did not come," Bolden said.
Furthermore, he said the goal of finding a way to respond to asteroid threats has been repeatedly put off by lawmakers who cite a lack of money.
Budget concerns also hamper the military's ability to monitor near-Earth objects and other space threats, such as orbital debris (defunct satellites and spent rocket stages that litter Earth orbit).
"We are clearly less capable under sequestration," Gen. William Shelton, the current commander of the U.S. Air Force Space Command, told the committee. He said that any further budget cuts could have dire consequences.
"Our dependence on space, not only for our way of life but also for military operations, is very high, so we would sacrifice that," Shelton said.
[Can you say RAPID CLIMATE CHANGE? - I thought you could...]
Meteor captured on camera in US
http://www.telegraph.co.uk/science/space/9949771/Meteor-captured-on-camera-in-US.html
Nasa has said that the flash of light that streaked across the sky over the US East Coast and was captured on security cameras appeared to be a "single meteor event".
A security camera above a car yard in Seaford, Delaware, and another in Maryland captured footage of what appeared to be a meteor travelling across the skyline late on Friday.
Nasa said that the flash of light that streaked across the sky over the US East Coast appeared to be a "single meteor event".
Bill Cooke of Nasa's Meteoroid Environmental Office said the meteor was widely seen, with more than 350 reports on the website of the American Meteor Society alone.
The sky flash was spotted as far south as Florida and as far north as New England, the newspaper USA Today reported.
Derrick Pitts, chief astronomer at Philadelphia's Franklin Institute, agreed that the sightings had all the hallmarks of a "fireball."
-t
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