For a long time now, there have been discussions concentrated upon the appearance of moon’s crater in the shape of a bull’s eye. This mysterious hole was a big question mark for scientists around the world. After decades of wondering about its occurrence, astronomers have finally revealed the formation of this bull-eye crater. The name of this hole is Orientale impact basin.
The three-ringed hole is situated on the side of the moon which was closer to the edge. If you will take a look at the moon from Earth, this hole is barely noticeable. The formation of the moon’s crater happened approximately 3.8 billion years ago. Three rings circle this bull-eye crater, the biggest measuring about 930 kilometers.
Finally, scientists managed to find an appropriate explanation for the formation of these rings. To reveal accurate data about Orientale crater, astronomers needed to analyze the interior structure of the moon. They have used the help of the NASA’s mission known as Gravity Recovery and Interior Laboratory (GRAIL).The goal of the mission was to carefully analyze the structure of the hole.
Researchers manage to use information about the gravity of the moon to determine the composition of the subsurface structure. After analyzing that data, experts have examined what determined the formation of the crater and its rings. Maria Zuber, a geophysicist at the Massachusetts Institute of Technology, explained that they relied on gravity to develop a map of the moon’s interior.
The subsurface layer is abundant in materials with different compositions, densities, and temperatures. Due to the existence of mountains and craters, the intensity of the gravity was varied around these landforms. By examining the variations in the gravitational field, specialists were able to determine what lies underneath the surface.
Jim Head, a co-author of the study and geologist at Brown University in Rhode Island, has argued that the scientists’ view on the moon’s crater was oriented to analyze only the surface characteristics. They did not have detailed data about the subsurface layer of the planet.
The GRAIL mission represented a significant help and contribution to this discovery. Scientists who were part of the mission managed to use a machine which X-rayed the moon’s crater. In this way, they connected the surface details with the subsurface characteristics.
Astronomers determined that a massive unidentified object which was traveling at 14 km/s hit the surface of the moon causing the crater. Another curious fact is that none of those rings that circle the crater have anything to do with the occurrence of the massive hole. They formed due to subsurface processes that occurred as a response to the impact.
Image source: wikipedia