A rock sample, collected by the Apollo 17 mission, reveals the structure of the light mantle, a clear casting that extends for 5 km on the lunar mantle.
The rock champions taken in December 1972 by the astronauts of the Apollo 17 are today offering new answers – and new questions – on one of the most mysterious formations of our satellite: the so -called Light mantlea vast clear casting that extends for about five kilometers at the base of the southern massif of the Taurus-Lutrow valley.
Scientists suspect that it is the residue of a gigantic landslide that took place millions if not billions of years ago. But what triggered it remains an enigma: impacts of asteroids, mountain collapses or even lunar earthquakes are all hypotheses involved. To go beyond the orbital images, the champions reported on the ground are needed: and one of these carotages, sealed for over fifty years and only recently opened, is revealing details never observed before.
Geological treasure. To lead the new research is Giulia Magnarini, a specialist in planetary geology. Analyzing the rock nucleus, his team was able to study the “Clasti “that is, the fragments of rock detached from the massif during the landslide. Thanks to the modern computerized micro-comography techniques, the scientists observed that the clasters themselves crumbled and contributed to making the landslide “scroll” as a fluid, on the earth it would be called “casting”, a surprising process for an environment without water like the moon.
“These champions are very precious,” explains Magnarini. “Not only do they tell us about the geological history of the site, but they also teach us how to preserve and study extraterrestrial materials in view of future missions, such as the Artemis program”.
Apollo 17: Record mission. The Apollo 17, took off on December 7, 1972, the last lunar mission of the Apollo program, was a shipping full of primates. In fact, the record for the longest stay on the lunar surface (over three days) established. He brought 110.5 kilograms of rocks to Earth, the most abundant load of all Apollo missions. He brought small animals for the first time – five mice – in lunar orbit, in an experiment on the effects of cosmic rays.
And above all, he marked the descent on the moon of the first scientist: Harrison “Jack” Schmitt, geologist, who together with the commander Eugene Cernan collected targeted champions and led observations of great scientific value. Not surprisingly, the Light mantle or Bright cloak It was one of the main objectives of the mission. Its mysterious origin intrigues scientists already then, and continues to do it today.
A link with the Tycho crater? An intriguing hypothesis connects the formation of Bright cloak At the great Tycho crater, one of the youngest and most spectacular of the moon.
The impact that generated it about 100 million years ago projected countless tons of high distance material, creating secondary craters that still radiate from its position today.
«It is possible that part of those debris precipitated in the region of the southern massif, triggering the landslide that created the Bright cloak »Magnarini observes. A hypothesis that the researchers are now testing, comparing the data of the Apollo champions with computer simulations. However, nothing takes away that the landslide triggered a long time earlier following the impact of a medium/large asteroid.
The future is Artemis. The foresight of NASA, who decided to keep part of the intact champions for future generations, turns out to be a winning choice today. Techniques non -existent in the seventies now allow to explore the champions with a precision comparable to that of advanced medical analyzes. In this sense, the research on Bright cloak It is not just a look at the remote past of the moon, it is also a bridge towards the future.
In fact, the knowledge acquired will contribute to preparing the next human and robotic explorations of the Artemis program, with the aim of establishing a lasting presence on our satellite. Fifty years later, the rocks collected by Cernan and Schmitt continue to speak. And perhaps, like half a century ago, they are opening the way to a new era of lunar exploration.
