Scientists know life on Earth began more than 3.8 billion years ago, but exactly how it began has long been an unanswered question.
Now a scientist in Texas believes he has the answer.
“This is bigger than finding any dinosaur,” Dr. Sankar Chatterjee, a professor of geoscience at Texas Tech University and curator of paleontology at the Museum Of Texas Tech University, said in a written statement. “This is what we’ve all searched for--the Holy Grail of science.”
It's long been known that the ancient earth was pummeled by asteroids, meteors and comets--and that these space rocks may have brought water and organic molecules to our planet. But Chatterjee has taken these ideas a step further. He argues that in addition to bringing water and the chemical constituents of life, the space rocks left impact craters that became "crucibles" in which the chemical reactions that ultimately gave rise to living cells took place.
Specifically, Chatterjee believes, meteorites punched giant craters into the Earth and deposited organic materials in them. Then icy comets that crashed into Earth melted, and filled these basins with water. Additional meteorite strikes created volcanically driven geothermal vents in the Earth's crust that heated and stirred the water.
The resulting "primordial soup" mixed the chemicals together, leading to the formation of molecules of ever increasing complexity--and eventually life.
“Segregation and concentration of organic molecules by convective currents took place here, something like the kinds we find on the ocean floor, but still very different," Chatterjee said in the statement. "It was a bizarre and isolated world that would seem like a vision of hell with the foul smells of hydrogen sulfide, methane, nitric oxide and steam that provided life-sustaining energy.”
To arrive at this conclusion, Chatterjee studied sites containing the world's oldest fossils in Greenland, Australia, and South Africa. He said these sites would be good candidates for where life began on Earth.
Has Chatterjee really found the biological Holy grail? Not every scientist is ready to give that claim his or her blessing.
"Whether or not these impactors were the critical ingredient for life remains to be seen, but further investigation of impact sites will nevertheless be informative for understanding Earth's early history," Dr. Jacob Haqq-Misra, an astrobiologist with the Blue Marble Institute of Science, who was not involved in the research, told The Huffington Post in an email.
Chatterjee presented his research Oct. 30 at the annual meeting of the Geological Society of America in Denver.