On the moon’s surface have found evidence of an ancient meteorite bombardment of Earth. Thanks to the discoveries, it became possible to trace the history of this event to the asteroid belt.
It is known that about 66 million years ago, when the Earth unfolded in Cretaceous-Paleogene extinction, present in the territory of Mexico hit a 10-kilometer asteroid that could cause mass destruction naletevshy dinosaurs and other animals. Left a crater the Chicxulub actively studied by geologists. But for hundreds of millions of years of constant restructuring and erosion of the earth’s crust erases traces of even the largest craters.
Therefore, in search of traces of the most ancient meteorite bombardment, scientists often turn to the moon. Located very close, she is experiencing almost all the same tests that get to the planet, and the lack of geological activity allows craters to remain much longer. This work was conducted by Japanese researchers, article which was published in the journal Nature Communications.
Kentaro Terada (Terada Kentaro) and his colleagues from Osaka University have estimated the age and structure 59 is relatively large (diameter about 20 km) craters that were taken by the Japanese lunar probe Kaguya. It appeared, at least eight of these craters appeared almost simultaneously, about 800 million years ago.
Not gas giants: Mini-Neptune can be completely covered with water
Based on the number, size and distribution of these craters, scientists believe that at the time, and the Moon, and the Earth survived heavy bombardment of fragments with a total mass of at least 40-50 trillion tons, which is ten times heavier than a hypothetical meteorite Chicxulub. The main suspects are the authors called chondrites family Eulalie — small planet and the source of a group of objects in the asteroid belt that formed about 830 million years ago.
Apparently, lounging in the result of an event, “ancestor” Eulalie has generated a huge amount of debris, some of which landed on planets, moons and the Sun; the rest remained within the asteroid belt, and part turned into earth. While the mass bombing of chondrites, about 800 million years ago, could bring the Land additional quantities essential for life phosphorus. And soon, the planet moved on to the next important stage of its existence — criogenia, during which not only was the most extensive glaciation, but the first animals.