Ours is a moon with two faces: the near side has a thinner and softer crust, while the farce crust is thicker and dotted by impact craters that are left almost undisturbed by lava flows.
The irregularities have scientific scientists for decades, and in a new paper, researchers use models to explore what may be possible explanations for the sharp differences. They claim that these characteristic sides can be the result of a giant percussion that strikes the moon and leaves a massive crater all around.
"The detailed gravity obtained by GRAIL has given new insight into the structure of the moon cross below the surface," said Meng Hua Zhu, a co-author of the new paper and a researcher at Macao University of Science and Technology in China in one statement released by American Geophysical Union, which publishes
Related: How the Moon was formed: 5 Wild Lunar Theories
The giant influence proposed by the researchers here would be just one in a long series of multi-collision collisions. One of the two current theories of what formed the moon in the first place is another, even greater influence ̵
This close-by-side influence would have come later, but still relatively early in our history. The researchers modeled 360 different collisions and compared all results to what we know about the moon today. That work suggests that an object such as the size of the great asteroid Ceres – 500-560 miles (800 to 900 kilometers) over could have done the trick.
Such an object would have had to arise fairly close to the two objects that originally collided to form the earth and the moon – to keep these elemental relationships so close. But the effect the scientists write could have left a crater extending 3,500 miles over the moon's surface and covering essentially the entire near side.
In their models, the hypothetical collision took on a number of differences between the two sides of the moon, including the extra layer that gives the thickness of the farce – which would have been formed by debris from the effect falling into a layer of 3 to 6 mils (5 to 10 km) thick.
If the research continues, it may shift other pronounced explanations, such as the idea that the earth originally had two minor, distinctive moons that collided to form the modern two-sided moon.
Researchers are hoping to set up their models with data from current and future moon missions, including China's Chang & e-4 mission which landed on the moon's outermost side in January.
The research is described in a pa per published Monday (May 20) in the journal JGR Planets.