The Moon still receives much impact from asteroids and other space objects. Though the Earth is also hit by such objects, many of them either burn in our atmosphere or else have the craters disappear in time due to erosion and vegetation. The large impact craters on the Moon though are still seen, and scientists have come to find out what those really mean.
Many of the large impact craters have been formed millions of years ago, such as the Orientale basin that was formed 3.8 million years ago. The Orientale basin can be found at the southwestern side of the Moon. From the Earth, the basin could barely be seen.
Perhaps the most prominent feature of the Orientale basin is the three concentric circles around it. These are said to be rings of rock and has scientists wondering what they are. The outermost ring is the largest with a diameter of around 580 miles.
Astronomers are studying the Orientale basin to find out how it is made. A number of the planets and satellites in the solar system have almost the same type of crater as the Orientale basin. Knowing about it can help astronomers know more about the history of the Moon, according to Science Daily.
"Big impacts like the one that formed Orientale were the most important drivers of change on planetary crusts in the early solar system," observed Brandon Johnson, lead author of one of the studies and co-author of another study. He is also at Brown University. Through him and other researchers, they have studied the images taken by the GRAIL missions in 2012.
The GRAIL missions have given astronomers better detail of the Orientale basin. Before that, there were images of it but were not as detailed as the GRAIL missions have provided. Jim Head, another geologist from Brown University and co-author of the study, said that the GRAIL images have given them more detail of its surface as well as its relation to the subsurface.
Through the GRAIL images, it has been found that none of the rings that are visible is the initial crater, as Maria Zuber of the Massachusetts Institute of Technology in Cambridge observed. She is also the lead author of one of the studies on it. Subsequent impacts that have formed the Orientale basin have erased the original crater, she added.
Orientale is the youngest among the multi-ringed large impact craters in the solar system, as Phys Org reports. By studying it astronomers can try to learn more about other impact craters like it, such as those found on Mars. Johnson and his team have created a computer model of the basin to see how the impact was formed and what happened after it.
The Orientale basin is just one of the large impact craters on the Moon. Astronomers are studying this to know what those impact craters really mean. As astronomers and other scientists try to know more, some mysteries of the solar system might be explained soon. Also reported earlier is that the Moon's surface is constantly changing.