Toronto: The number of asteroid impacts on the Earth and the Moon increased by two to three times starting around 290 million years ago, according to a study. The finding, published in the journal Science, challenges our understanding of a part of Earth's history by looking at the Moon, the most complete and accessible chronicle of the asteroid collisions that carved our solar system. "Our research provides evidence for a dramatic change in the rate of asteroid impacts on both Earth and the Moon that occurred around the end of the Paleozoic era," said Sara Mazrouei from the University of Toronto in
Canada. "The implication is that since that time we have been in a period of relatively high rate of asteroid impacts that is 2.6 times higher than it was prior to 290 million years ago," Mazrouei said.
It had been previously assumed that most of the Earth's older craters produced by asteroid impacts have been erased by erosion and other geologic processes. However, the new research shows otherwise.
"The relative rarity of large craters on Earth older than 290 million years and younger than 650 million years is not because we lost the craters, but because the impact rate during that time was lower than it is now," said Rebecca Ghent, an associate professor at the University of Toronto. "We expect this to be of interest to anyone interested in the impact history of both Earth and the Moon, and the role that it might have played in the history of life on Earth," Ghent said.