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Gulf of Mexico

USA

Chicxulub crater

Drill Site

200km

us more about the response of the world’s plants to

the event – and the dinosaurs that depended on them.

Similar analysis has been carried out elsewhere, but

the Chicxulub cores contain large amounts of material,

so it should be possible to build up a more accurate,

high-resolution picture of the events that led to a mass

extinction.

LIFE DOWN BELOW?

There might even be signs of actual life in the rubble-

like breccia and beneath – microorganisms that have

been living and evolving deep underground, far from the

human eye, for many millions of years.

“Most of life on Earth is underground,” says

Charles Cockell, an astrobiologist at the University

of Edinburgh. “Something like a massive asteroid

impact that killed off the dinosaurs would also have

dramatically disrupted the deep biosphere, particularly

at the place of impact,” he says. “But it may not

necessarily have been all bad.”

A decade ago, Cockell was part of a similar project

in Chesapeake Bay in Virginia on the east coast of the

United States, the site of a smaller and, at 35 million

years old, more recent impact. This event appears to

have fractured the underlying rock, improving the flow

of water and creating a habitat that would have been

particularly suited to microbial life, he says. “We found

there was an increase in the numbers of microbes in

impact-fractured rocks.”

The same may have occurred at Chicxulub. “The

breccia is almost like chicken soup for microbes,”

says Cockell. “It’s got everything in it that’s leaching

out and providing food for microbes.” PHOTOS: MAX ALEXANDER/B612/ASTEROID DAY ILLUSTRATION: ACUTE GRAPHICS

TOP: A clump of breccia

recovered from the

impact crater

ABOVE: The drill site lies

30km off the coast of

Mexico

“I was super stressed before I got

on the platform. When the super

gorgeous cores began to come out of

the ground, the stress vanished”

SCIENCE