Biologists Discover Ancient Microbial Ecosystems Beneath The Dinosaur-Killer Crater
How did life arise on Earth? How did it survive the
Hadean eon, a time when repeated massive impacts excavated craters thousands of kilometres in diameter into the Earth's surface? Those impacts turned the Earth into a hellish place, where the oceans turned to steam, and the atmosphere was filled with rock vapour. How could any living thing have survived?
Ironically, those same devastating impacts may have created a vast subterranean haven for Earth's early life. Down amongst all those chambers and pathways, pumped full of mineral-rich water, primitive life found the shelter and the energy needed to keep life on Earth going. And the evidence comes from the most well-known extinction event on Earth: the Chicxulub impact event.
A new study presents evidence that the Chicxulub crater was host to an enormous subterranean network of hydrothermal vents that could have provided a sanctuary for microbial life.
By extension, much earlier impact craters likely provided the same sanctuary. The study is titled 'Microbial Sulfur Isotope Fractionation in the Chicxulub Hydrothermal System'. The lead author is David Kring from the Lunar and Planetary Institute. It's published in the journal
Astrobiology.
The idea that life could have arisen and persisted in the network under impact craters is called the impact origin of life hypothesis. David Kring is a leading scientific voice supporting that hypothesis.
While massive repeated impacts made Earth's surface uninhabitable during the Hadean eon, the same wasn't likely true of the region under the impact craters.
According to Kring, those same impact events "…were producing vast subsurface hydrothermal systems that were perfect crucibles for pre-biotic chemistry and habitats for the early evolution of life." ...