On Earth circa four billion years ago, life was hard. Frequent asteroid strikes turned parts of the planet into molten rock. Food and livable spaces were few and far between. What was a microbe to do to survive? Some very early life could have made it by staying deep—living as far as six miles below the seafloor.
The crater made by the asteroid that killed off the dinosaurs is revealing clues to the origins of life on Earth. Scientists have drilled into the 200km-wide Chicxulub crater now buried under the Gulf of Mexico. They say its rocks show evidence of having been home to a large "hydrothermal system", where hot fluids flowed through cracks and fissures.