Last December, the Chinese moon landing ship Chang’e 5 returned to Earth with the first rocks and lunar dust since 1976. Recent analyzes have shown that these were the youngest ever taken from our natural satellite, thus redefining its geological chronology.
A first since 1976
Featured in the journal Science, this new research is among the first to be published for the mission Chang’e 5, whose completion made China the third country to report lunar samples on Terre, after the United States and theSoviet Union. Rocks collected during missions Apollo and Luna 1960s were all at least three billion years old, indicating to geologists that the Moon had not seen any volcanic activity since.
However, remote images taken recently of the lunar surface have suggested that there are rocks much younger than this. The mission Chang’e 5, designed to collect rocks from some of the younger volcanic surfaces of the Moon, was the perfect opportunity to confirm these suspicions.
An international team of scientists used large mass spectrometers to study the chemistry of these new lunar samples and analyze the decay of the radioactive elements they contained, fixing their age at around 2 billion years.
« After analyzing the chemistry of lunar rocks collected as part of the recent Chinese mission, we determined that the new samples were around two billion years old, making them the youngest volcanic rocks identified on the Moon to date. », Explains the professor Alexander Nemchin, researcher atCurtin University, on Australia, and lead author of the study.
Such results not only disrupt the chronology of recent volcanic activity from our natural satellite, but also confirm the effectiveness of remote observation techniques, which bodes well for the study of other planets.
« They confirm what experts have long predicted based on remotely obtained images of the Moon and raise further questions about the presence of these young basalts », Explains the professor Gretchen Benedix, co-author of the study. ” The next step will consist in identifying a mechanism explaining how this relatively recent warming of the Moon could have favored the formation of basaltic magmas whose temperature exceeds 1000 ° C, which will ultimately help to improve the dating of the age of the Moon. ‘entire solar system. »
As part of its ambitious space program, the China plans other lunar missions, including missions Chang’e 6, 7 and 8, all of which are expected to take off in this decade. These will explore the Moon in search of resources and areas to consider the establishment of a potential lunar scientific base.