Microscopic glass fragments from The Moon have revealed a history of lunar impacts that lines up precisely with meteorite impacts here on Earth – including the Earthquake by giant asteroid 66 Million Years AgoThis caused the extinction of most human life on Earth. dinosaurs.
A team of scientists used various techniques to trace 135 tiny beads of glass. They were returned to Earth by the Chinese National Space Agency’s Chang’e-5. Sample return missionTo the time they were formed.
These results may shed light on the impact events that have changed our world.
“We found that some age groups of the moon glass beads match the ages of some the largest terrestrial impactcrater events, such as the Chicxulub impactcrater responsible. dinosaur extinction event,” says geologist Alexander NemchinCurtin University, Australia
This study also indicates that Earth may be subject to large-scale impact events, such as Chicxulub. asteroidThat ended the reigning dinosaurs, but could have been accompanied several other smaller impacts.
“If it is true,” Nemchin“It suggests that the age frequency distributions of Moon impacts could provide valuable information about Earth’s impacts or the inner Solar System.”
A meteorite or asteroid impact can produce tremendous heat and be extremely energetic. If silicate material is present – which it is, on both Earth and The Moon – this heat can cause melting and reformation found later in the form of tiny glass beads, called impact spherules.
There are other types of materials that can be found on the Moon than silicates. In some cases, these other materials can become entangled in impact spherules so large that it is possible to analyze them.
This means scientists can get hold of the spherules and study them in order to discover more about how they formed. It was possible to do this with the Chang’e-5 lunar return mission.
Tao Long, a geologist at the Chinese Academy of Geological Sciences, Beijing, identified 215 spherules from soil Chang’e-5 and began their analysis.
Some spherules did not contain enough material for detailed analysis. Researchers conducted many tests on the remaining 135, in order to determine their age.
This technique uses radioactive decay to convert uranium to lead. Knowing how long it takes for uranium to decay, we can use the relative amounts of lead and uranium in samples to estimate the sample’s age.
“We combined a wide variety of microscopic analytic techniques, numerical modeling and geological studies to determine when and how these microscopic glasses beads from the Moon formed.” Nemchin:.
These spherules are mainly localized in the area around Chang’e-5. However, simulations indicate that they could be flung about 100 kilometers (62 mi) from the impact spot.
These simulations also indicate that the spherules were formed mainly by impacts leaving craters of 100- 1,300 meters (328-4,265 feet) in their wake. The team was able to identify possible craters in the area where they formed using this information.
In age, the spherules ranged between a few million and 2 billion years old – that upper range was when the basin in which Chang’e-5 landed was resurfaced with fresh volcanic basalt. The 34 and 68-year-old spherules are particularly interesting. The Chicxulub Event is the first, the latter includes a few craters dating back to the Eocene.
Although it could be a coincidence, the parallel timing suggests that the origin point of these events – possibly a smash-up in the asteroid belt – could have produced many rocks that simultaneously hit Earth and the Moon. This could offer new insights into the dynamics of the asteroid Belt and how impactors evolve.
“The next step” Katarina Milenkovic, a planetary scientistCurtin University stated that “would be to use the data from these Chang’e-5 sample with other lunar soils, crater ages, to be able uncover other Moon-wide impact events, which might in turn reveal new evidence about how impacts may have affected Earth’s life.”
The research was published in Science Advances.
