A new study has revealed that the meteorite which wiped out the dinosaurs also created a life-supporting underground environment that lasted for eight million years. Researchers from the University of Glasgow and other institutions analyzed samples from the Chicxulub crater in Mexico, formed 66 million years ago when a 10-kilometer-wide asteroid struck Earth.
Impact and Aftermath
The catastrophic impact triggered an extinction event that killed about three-quarters of Earth's plant and animal species, including all non-avian dinosaurs. The crater left behind is nearly 200 kilometers in diameter. However, beneath the surface, the immense heat generated by the collision created a hydrothermal system. Rocks melted by the impact mixed with seawater from the Gulf of Mexico, forming porous material filled with tiny pockets of heated water—ideal conditions for microbial life.
Long-Lived System
Using argon-argon dating, Dr. Annemarie Pickersgill of the Scottish Universities Environmental Research Centre determined the ages of samples taken from the crater in 2016. The results showed that the hydrothermal system persisted from 66 million to about 58 million years ago, far longer than previous estimates of two million years based on computer models.
Dr. Pickersgill stated: "Wherever on Earth you find flowing warm water, you find life, and we’ve known for a while that asteroid impacts create hydrothermal systems. Previous research suggested the system lasted about two million years, but we were surprised by our findings."
Implications for Life on Other Planets
The team also used computer modeling to understand why the system lasted so long. They found that high rock permeability, sustained heat from the impact, and natural geothermal conditions contributed to its longevity. These findings could help direct the search for life on other planets, such as Mars, which has experienced many impacts during its history when water may have been abundant.
Dr. Pickersgill added: "The porous, fractured rocks created by impacts create microenvironments where microorganisms can be protected from radiation and extreme temperatures. Those conditions give life the chance to take hold and flourish, as likely happened on early Earth. These findings could help future missions identify impact craters most likely to have sustained life."
The study, published in Communications Earth & Environment, involved researchers from Scotland, England, Germany, the US, and Canada.
