Study describes the formation of ring creator on the moon read more at here www.spinonews.com/index.php/item/1444-study-describes-the-formation-of-ring-creator-on-the-moon

Three concentric rock rings mark a massive depression on the lunar surface, an impact basin known the Mare Orientale. How exactly the impression formed has puzzled scientists for decades.

However, a pair of new studies offer answers. Scientists at NASA and Brown University, armed with data from the Gravity Recovery and Interior Laboratory (GRAIL) spacecraft, have for the first time built a model explaining the crater's formation 3.8 billion years ago.

Brown geologist Brandon Johnson, lead author of one of the study explained big impact like the one that formed Orientale were the most important drivers of change on planetary crusts in the early solar system.

The new GRAIL data allowed scientists to peer beneath the lunar surface and study the subsurface structures underlying Mare Orientale.

Jim Head, a Brown geologist and scientists on the GRAIL mission, said, the beauty of the GRAIL data is that it is putting Orientale in an x-ray machine and learning in detail what the surface features correspond to in the subsurface.

In most large collisions, the surface rebounds in the aftermath of the shock, erasing the initial impact crater. Such is the case with Orientale. But, GRAIL helped scientists find the initial impact beneath the surface. The discovery allowed scientists to estimate how much rock was blasted out by the initial impact.

The data also allowed scientists to build a model simulating the impact and the rebound, revealing the formation of the three rings. The rebounding crust, hot and pliant, initially flowed inward toward the impact.

As the rock flowed inward, it created large cracks and cliffs which formed the outer two rings. The inner ring is formed as molten rebounding material flowed outward, mounding in circular shape.

This was a really intense process. These several-kilometer cliffs and the central ring all formed within minutes of the initial impact.

Johnson said, researchers hope to use their model to study ring formations on other planets, like Mars. There are several basins of this kind on Mars. However, compared to the Moon, there's a lot more geology that happened after these impacts that degrades them.