The impact crater in Yaruba, with a diameter of about 70 km and difficult to identify due to the erosion of its original structure, is classified as the oldest on the planet. But scientists were previously unable to determine its exact age.
Thanks to a highly accurate dating technique, researchers at Curtin University in the Australian city of Perth succeeded in targeting metal pellets that “recorded” the shock of the impact through a recrystallization path, according to a study published in the journal Nature Communications.
Scientists have concluded that the impact crater in Yarubaoba formed 2,229 billion years ago, a date that coincides with the end of a freezing phase called the “Earth Snowball”.
“There is geological evidence (other than that related to the study) that is based on the presence of conglomerates and volumes on Earth before a period of between 2.4 billion,” Timmons Erickson of the Johnson Center at NASA, the lead author of the study, told AFP. Years and 2.2. The most recent cluster found in South Africa corresponds to the age of the impact crater in Yaruba.
“It is interesting to note that the conglomerates of ice have been absent in this place from the memory of minerals for nearly 400 million years after the impact,” said Christopher Kirkland, who is also the author of the study.
The researchers thus presented a hypothesis based on a rule for preparing digital embodiments, according to which an asteroid hit a frozen region and violated a layer of ice with a thickness of 5 kilometers, then tossed into the atmosphere a huge amount of water vapor, up to 500 billion tons.
These ejected amounts of water vapor, “a greenhouse gas that is stronger than carbon dioxide,” caused a warming that helped the planet out of this ice age.
This scenario is phenomenal, since most asteroid impact craters have been associated with a comprehensive decrease in temperature, and the most famous example is the asteroid that struck Yucatan in Mexico and ended the domination of dinosaurs about 66 million years ago.