The catastrophic impact of an enormous asteroid around 66 million years ago sparked the most dramatic mass extinction event Earth has ever seen, wiping out all almost all living organisms on the planet – including the dinosaurs. Exactly how life managed to re-emerge from the burning embers of the resulting post-apocalyptic wasteland remains somewhat unknown, which is why an international team of researchers is now preparing to drill some 1,500 meters (4,900 feet) into the Chicxulub crater in search of clues.
Drilling is expected to begin at the end of this month in the Gulf of Mexico, providing scientists with a unique opportunity to examine the geological and microbial composition of the various layers of rock built up since the impact. In doing so, they hope to learn more about how the intense force of the collision displaced material beneath Earth’s surface, and what effect this may have had on the microorganisms that ultimately gave rise to the diversity of life present today.
Sponsored by the International Ocean Discovery Program and the International Continental Scientific Drilling Program, the project will give researchers a chance to examine structures known as peak rings, which they expect to find at a depth of between 800 and 1,500 meters (2,600 to 4,900 feet). These have been observed in other asteroid craters on the Moon and Mars, yet have never previously been studied on Earth.
According to existing theories, these are caused when asteroid impacts displace material from beneath the surface, resulting in the creation of columns of volcanic material that can be seen above the rim of the crater. It is thought that these towers may initially be filled with hot fluids derived from subterranean geothermal systems, providing a suitable environment for certain microbes to flourish.
By searching for the remnants of microbial DNA within the impact layer, as well as examining the nature of the rocks that make up these peak rings, the researchers hope to be able to confirm this theory. For instance, they may find evidence of microorganisms capable of metabolizing the sulfur within these fluids, thereby enabling their survival in the oxygen-deprived environment that existed in the aftermath of the impact.
Should these hypotheses be validated, it could help to explain how the asteroid, in addition to causing a mass extinction, also provided the conditions for life to re-establish itself.