Dino-killing asteroid put a dent on Earth’s crust: Study

Houston: The asteroid that ended the age of dinosaurs about 65 million years ago may have nearly punctured the Earth’s crust, and temporarily caused the surface of the planet to behave like a slow-moving fluid, a new study has found. The findings may shed light on how such impacts can reshape the face of planets and generate new habitats for life, researchers said. Major craters sometimes possess rings of rocky hills in their centres known as peak rings. Most of these peak rings exist on extraterrestrial rocky bodies such as the Moon or Venus, making it difficult to analyse these structures in detail and pin down their origins. To learn more about peak rings, scientists from University of Texas at Austin in the US studied the gargantuan Chicxulub crater in Mexico, which measures more than 180 kilometers across. It is the only crater with an intact peak ring on Earth. The crater resulted from the epic crash of an object about 10 kilometre wide, and the resulting impact is thought to have ended the age of dinosaurs about 65 million years ago. Researchers examined peak ring samples from under 18 metres of water in the Gulf of Mexico. They discovered granite that likely once was deeply buried for about 500 million years, said Sean Gulick, a marine geophysicist at UT Austin. “These deeply buried rocks rose up to the surface of the Earth within the first few minutes of the impact,” Gulick told the ‘Live Science’. After the impact, “the earth there would have temporarily behaved like a slow-moving fluid,” Gulick said. “The stony asteroid would have opened up a hole probably almost the thickness of Earth’s crust, almost 30 km deep, and on the order of 80 to 100 km wide,” he added. —