The Record (Bergen County, New Jersey)
Scientists have begun drilling a mile-deep hole into a huge underground crater that was left by a mountain-sized asteroid or comet that slammed into Earth 65 million years ago. According to a widely accepted theory, the cataclysmic event wiped out the dinosaurs.
This month, the scientists reached the uppermost layer of broken rocks buried beneath Mexico's Yucatán Peninsula that were smashed, twisted, and hurled about by the tremendous force of the collision.
The researchers hope to learn exactly what the space invader did when it penetrated Earth's crust in a fiery ball of unimaginable violence. The goal is to better understand how the impact devastated the global environment, clearing the way for the rise of mammals, including humans.
"Since we can't go back 65 million years in a time machine, drilling down to the 65-million-year level is the best we can do," said James Powell, the executive director of the National Physical Science Consortium at the University of Southern California in Los Angeles.
Time of Transition
The ancient catastrophe marked "the transition between the Age of Reptiles and the Age of Mammals," said David Kring, a planetary scientist at the University of Arizona in Tucson and a leader of the drilling team from Mexico and the United States.
"Mammals were able to develop because the impact caused a complete change in the biological landscape of Earth," he added. "Then evolution took advantage of the change."
The smashed rubble, technically known as breccia, was found 2,800 feet (853 meters) below ground, about 25 miles (40 kilometers) southwest of the Yucatán city of Merida. The crater is called Chicxulub (pronounced cheek-shoo-loob) for the village located over its center.
Kring, a principal investigator in the Chicxulub Scientific Drilling Project, said the drilling would bring up rocky cores about as thick as a baseball bat that would reveal the complete history of the ancient disaster.
"For the first time, we will be able to see the entire geology of the structure, all the way down to the bedrock of the continental crust," he said.
Between the breccia and the bedrock, researchers expect to find a thick stony sheet that was melted by the intense heat of the long-ago crash. The volume of the molten material could have been as much as 24,000 cubic miles (100,000 cubic kilometers), enough to fill Hudson's Bay or the Gulf of California with lava.
