Researchers from Australia, Great Britain, China and the United States determined that the age of the lunar soil delivered to the land of the Chang’e 5 mission is 1.96 billion years old – which speaks about relatively recent volcanic activity. The article of scientists was published in the journal Science.
The returnable capsule of the Chang’e 5 apparatus delivered on December 16, 2020 to Earth 1.73 kilograms of lunar regolith. The place of his fence – the ocean of storms – it was not chosen by chance: it is known that this is one of the most geologically young sections of the surface of the moon.
To measure the age of the soil, researchers from the Institute of Geology of the Chinese Academy of Sciences, together with foreign colleagues, chose two samples of about three to four millimeters. The analysis of the ratio of lead isotopes showed that their age is 1963 plus-minus 57 million years. “This is a phenomenal result. From the point of view of planetary time, this is a very accurate definition,” said one of the researchers, Professor of Washington University in St. Louis Brad Joliff.
According to him, the discovery will help fill the “space” in the geological history of the Moon between the three billion years old – the age of samples delivered to the APOLLO missions – and a billion years, when some permanent shock craters were formed. Breed dating will help to improve the so-called craters counting method. The moon is used as a “clock” for the entire solar system – only it can relate the number of crater in a certain area with its rocks. The extrapolation of this data allowed the age of many regions of Mars, as well as satellites of Jupiter and Saturn.
Samples are lunar basalts – rocks formed during volcanic eruptions. This fact indicates relatively late volcanic activity on the moon – contrary to the established convictions that it ended relatively early. “We also showed that the type of basalt does not like previously discovered in the lunar rocks. This suggests that they come from another part of the moon mantle,” another study author, a teacher of Manchester Catherine Joy, notes.
previously researchers from China, Germany and the United States analyzed the chemical composition of the lunar soil delivered by Chang’e 5 – and found “exotic” fragments.