August 5, 2012 8:54
Life on Earth may have originated in the 500 million years earlier than previously assumed. First organisms have appeared 4.4 billion years ago, and even "firing" a huge asteroid from space could not destroy them, according to a new study. The results of the work of scientists from the United States published in the journal Nature.
Previously, many scientists have argued that during the so-called "late heavy bombardment" of about 3.9 billion years ago the earth's crust melted and life, if it existed before, died, wrote sunhome.ru
However, three-dimensional computer model, created by scientists at the University of Colorado (Boulder), refutes this view, says the agency Reuters.
According to U.S. experts, many habitable earth's crust had survived along with microbes. Thus, life on this planet could come at a time when the oceans were formed first, says Oleg Abramov, one of the authors issledovaniya.V progress of Colorado scientists examined data on lunar rocks, samples of meteorites and impact craters on neighboring planets. As a result, they have created a three-dimensional model of the "bomb" and found that the meteorites would have destroyed much of the organisms, but life in general.
Of course, the surface of the Earth has long been unsuitable for life, recognizes Abramov. However, in hydrothermal vents beneath the surface of heat-loving microbes might not just survive, but thrive both incubators, said the scientist.
"When did life began on Earth — a very controversial issue — says Michael New, an astrobiologist agency NASA, which funded the study. — These findings are important because they show that life could have started long before the "late heavy bombardment", the so-called gadeysky period of Earth's history — from 3.8 to 4.5 billion years ago. "
At present there are fossils of organisms that lived 3.5 billion years ago, geochemists and data indicate that primitive organisms could exist for over 300 million years before that.