Asteroids could create life on Earth: biologists discovered microbial ecosystems in ancient craters

Asteroids could create life on Earth by leaving craters

The question of how life arose on the Earth has no clear answer. The scientists argue on that topic, figuring out how life could survive during a period when the planet was subject to frequent asteroid impacts, forming craters thousands of kilometers across the Earth. These impacts turned the planet into a hellish place. The oceans became vapor, and the Earth's atmosphere was filled with rock gases. Could at least one living creature survive in such conditions?

But modern science came to the conclusion that even the most destructive blows could have a constructive effect. The impacts of space objects created vast underground shelters for early life on the Earth.

They were rich in minerals and water, and in these formations, primitive life found refuge and energy that are necessary for sustaining life on the planet. A striking example of that is the impact of an asteroid that formed the Chicxulub crater. A new study found an evidence that the crater contained a powerful network of underground hydrothermal vents. They could serve as a refuge for microbial life.

A lead researcher David Kring supports that hypothesis, calling it the theory of the impact origin of life on the planet. Vast underground systems provided the necessary conditions for the early evolution of life. The arguments supporting the assumptions, the researchers supported the results of programs for the study of rock cores from the Chicxulub crater ring.

They were recovered from a borehole approximately 1.3 kilometers deep. The samples were found to contain miniature spheres of pyrite, framboids, only 10 millionths of a meter in diameter. Pyrite is an iron sulfite. It contains sulfur isotopes that show that framboids were formed by microbes.

And microbes, in turn, were part of an ecosystem adapted to the mineral fluid heated by asteroid impacts that fills the underground network. And the network was located just under the ring of the impact crater peak.

For their survival, microbes received energy from chemical reactions in the system of rocks and liquids, turning the sulfate of the liquid into sulfide that was subsequently preserved in the form of pyrite. Similar thermophilic microbes are still found today in deep ocean hydrothermal vents and hot springs in the Yellowstone Park.