the joint team of scientists from Institute for Solar system research max Planck in Germany and the ETH Zurich have made the first global map of rock falls on the moon. Analysis of the data showed that they are not caused by lunar “earthquakes”, as previously thought, and external impact.
a Brief report on the work published on the website of the max Planck Institute and the full study can be found in the journal Nature Communications. The first global map of rock falls on the moon were created on the basis of data analysis more than two million images that scientists have been able to find in the archives.
Only it dealt 136 610 events. Moreover, the analysis showed that even the oldest lunar landscapes are still in the process of its formation. Individual boulders on steep slopes and rocks can slide, roll and even bounce. This process, known as the rockfall is happening not only on Earth but on the moon.
the Boulders and the boulders on the moon is not just moving down the slopes, leaving visible furrows. This phenomenon occurs since the first unmanned flight to the moon in the 1960-ies.
During the mission “Apollo” astronauts explored a few of these tracks on the moon and brought samples of displaced stone blocks on the Ground. However, until now, a clear picture of the extent of rockfall scientists were not. Map creation made it possible not only to evaluate but to obtain a new view on this process.
“the Vast majority of displaced boulders on the moon have a diameter of from seven to ten metres, – explains the study’s lead author Valentin Bickel. Earlier space probes that studied the moon, could not detect such small objects in a global scale.”
In the new study, and most of them were used by a neural network. Artificial intelligence taught to recognize the typical traces of rockfall on satellite imagery. It is possible to find the displaced stones even very small diameter, up to 2.5 meters.
in addition, the card has helped to systematize data and to establish the most likely causes of rockfalls. Previously, scientists assumed that the main reason for this is the lunar “earthquakes”. New data suggests that a much more important role in this process is played by the asteroid impact.
They are, according to scientists, are responsible for more than 80 percent of all detected rockfalls. The traces of most of them are near the walls of the craters. It is also established that some of the boulders moved immediately after the asteroid impact, while others – much later.
the Researchers gave an explanation. According to them, the asteroid impact capable of creating a network of cracks, which gradually increasing. As a result of separate sites of a surface can be unstable even over a very long period of time.
Surprisingly, traces of landslides were found even in areas of the landscape which was thought to have been formed about four billion years ago. Typically, such fingerprints disappear after a few million years.
As they were still visible on the surface, scientists have suggested that these areas are still subject to erosion and rockfalls on them continues. The researchers say that only where there craters, rock can have seismic or volcanic origin.