WASHINGTON — Scientists have discovered evidence that a comet or a space rock collided with the Earth some 56 million years ago, unleashing perhaps a massive warming that began at that time.
it Is an idea that has caused great debate among scientists, many of whom question whether there is a link. Scientists study the mysterious warming to better understand the current climate change caused by human activity, and the future of the planet.
Makes about 56 million years ago, the Earth warmed up between 5 and 8 degrees Celsius (9 and 14 Fahrenheit) and then returned to normal, in a period of 100,000 years. That contributed to some extinctions and the emergence of mammals. Some theories on the cause have pointed to an increase of carbon in the atmosphere due to numerous volcanic eruptions, a volcano in Greenland that burned up a huge deposit of coal and a sudden vanishing sub-ocean methane. But a new study published in the journal Science points to a possible link with a collision and cosmic.
at The same time the Earth began to warm, seems to have been hit by a space object that sent debris flying over north America, according to tests of samples of soil in New Jersey and Florida. Scientists have not found a crater or a space object. Instead, they found what they say are rocks near supercalentadas by the collision.
The main author of the study, Morgan Schaller, a professor at the Polytechnic Institute Renssalaer, it does not say exactly that the shock caused the massive increase in carbon and warming, but points out that the time of the events is suspect.
“What we are saying is that it is a coincidence really extraordinary,” said Schaller. “We need to examine this much more carefully”.
however, the co-author Dennis Kent, a professor of geology at Rutgers University and at Columbia, wrote in an e-mail message that may be, in some part, an impact crater which he called the “zero point” of the heating event.
The team of Schaller was examining sediments at two locations in New Jersey and one in Florida some 56 million years ago, in search of certain fossil small, when they saw repeatedly tiny objects of glass. The objects measure 100 microns approximately (.004 inch; 0.01016 centimeters), sometimes in the form of a sphere, sometimes as a drop. All showed signs of having an identity unique chemistry of quartz that was generated by a super-heating.
it Is a sign typical of the remains of a comet or asteroid vaporized on impact with the Ground, said Schaller. And all come from the same period in the sediments of the heating mass of the planet, known as the Thermal Maximum of the Paleocene-Eocene (MTPE).
Schaller said his team until now have not found where he would be the crater or the dimension that the object would have.
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