[ad_1]
Scientists have discovered that the moon is experiencing its own version of earthquakes, which makes it shrink.
The so-called "moon tremors" result from its tectonic activity and force our natural satellite to wrinkle "like a grape".
Its interior is cooling, causing the contraction of the surface, but the fragile surface cracks and forms a cliff-shaped "escarpment".
They measure about ten meters high and a few kilometers long and look like a giant staircase on the lunar surface.
They were first discovered over 50 years ago by Apollo astronauts and the analyzes showed that they were still in training.
Scroll for the video
This prominent flaw is one of thousands of discoveries on Lunar Reconnaissance Orbiter Moon (LRO) from NASA. These faults look like small steep cliffs or escarpments. Pumps are formed when part of the crust of the moon (arrows pointing to the left) is pushed onto another part (arrows pointing to the right) when the moon's interior cools and decreases
Scientists superimposed the epicenter location data on images of NASA's Lunar Reconnaissance Orbiter (LRO) escarpments.
According to researchers, at least eight of the 28 stilettos recorded from 1969 to 1977 were likely the result of true tectonic activity.
This is the movement of the plates in the lunar crust that create "thrust faults".
They say that these scars on the surface of the moon are more likely to be formed as a result of moon tremors than as a result of asteroid impacts or rumblings in the depths of the interior.
NASA hopes to return to the moon in the coming years and this revolutionary discovery could accelerate their plans.
Professor co-author Nicholas Schmerr, a geologist at the University of Maryland, said, "We have discovered a number of earthquakes recorded in the Apollo data that ran very close to defects found in LRO images. "
The photographs also show physical traces of geologically recent fault movements, such as landslides and boulders.
He said: "It is very likely that the mistakes are still active today.
"You do not often see active tectonics anywhere other than on Earth – so it's very exciting to think that these faults can still produce moon tremors."
The discovery of young faults less than 50 million years old by the LSO camera in 2010 has been interpreted as evidence of lunar tectonic activity.
US and Canadian researchers have examined earthquakes recorded by seismometers at Apollo landing sites 12, 14, 15 and 16.
Using an algorithm, they discovered that the epicenters of eight earthquakes, more than a quarter, were within 30 km of the visible breakouts in the LRO images.
It was close enough to conclude that the Moon is currently active on the tectonic plane.
The LRO's camera identified thousands of oddly shaped cliffs – extending from the south pole to the north – and discovered that the moon was still narrowing.
The Apollo instruments recorded their last earthquake shortly before their retirement in 1977.
But the moon is probably experiencing earthquakes to this day, say the researchers.
Shallow tremors would have ranged from two to five on the Richter scale if they occurred on Earth.
This would be enough to damage buildings and other structures.
The researchers also found that six of the eight earthquakes occurred when the moon was at or near its peak, the furthest point on Earth's orbit.
It is here that the extra tidal stress due to the gravity of the Earth causes a peak of total pressure on the crust of the moon, which makes it more likely to slip along the pushed faults.
The lead author, Dr. Thomas Watters, a scientist at the Center for Earth and Planetary Studies at the Smithsonian Institution in Washington, said: the global contraction and tidal forces, indicating that seismometers Apollo recorded the contraction of the moon and that it is still active on the tectonic plane. & # 39;
The moon wrinkles as its interior cools and shrinks, as does a grape when it dries to become a grape.
But unlike the supple skin on a grape, the crust of the moon is fragile, which makes it break when the inside shrinks.
This results in thrust defects in which a section of the crust is pushed onto an adjacent section.
Shallow tremors would have ranged from two to five on the Richter scale if they occurred on Earth. This would be enough to damage buildings and other structures (stock)
The LRO has photographed more than 3,500 fault traps on the moon since it was commissioned in 2009.
Some of these images show landslides or rocks at the bottom of relatively clear areas on the slopes of fault escarpments or nearby terrains.
As the weather gradually darkens the materials on the lunar surface, the lighter areas indicate areas freshly exposed by an event such as an earthquake.
Other LRO defect images show fresh traces of falling rocks, suggesting that earthquakes have sent these blocks down the slopes of their cliffs.
These traces would fade relatively quickly, in terms of geological time, by the constant rain of micrometeoroids impacts on the moon.
With nearly a decade of LRO footage already available and further advances in the coming years, the team would like to compare images of regions of specific faults from different eras to look for new evidence of recent moonquakes.
Professor Schmerr said, "For me, these results underscore the need to return to the moon.
"We learned a lot from the Apollo missions, but they only scratched the surface.
"With a larger network of modern seismometers, we could make tremendous progress in our understanding of the geology of the moon.
"This gives very promising fruits for science in a future mission on the moon."
The study was published in the journal Nature Geoscience.
[ad_2]
Source link