A new discovery about the Moon’s surface is made by the Lunar Reconnaissance Orbiter Camera (LROC) on NASA’s Lunar Reconnaissance Orbiter spacecraft.
Scientists find that the Moon’s surface is being “gardened” – churned by small impacts – more than 100 times faster than they previously thought.
This means that surface features believed to be young are perhaps even younger than assumed.
In addition, any structures placed on the Moon as part of human expeditions will need better protection.
The finding is newly published in Nature.
Scientists from Arizona State University and Cornell University led the study. They have been studying the high-resolution lunar images for more than 7 years.
Before the Lunar Reconnaissance Orbiter was launched in 2009, researchers thought that it took hundreds of thousands to millions of years to change the lunar surface layer significantly.
But now they discovered that the Moon’s uppermost surface materials are completely turned over in something like 80,000 years.
During the seven years the mission has run so far, the team identified 222 new impact craters that formed during the mission.
The number of new craters is greater than anticipated by standard impact-modeling rates used by lunar scientists.
The discovery has the effect of giving lunar surface features younger ages.
Theory says that a lunar geologic unit should accumulate a certain number of craters of a given size in a million years, for example.
But if it turns out that impacts are making craters more quickly, then it takes less time to reach the benchmark number, and the geologic unit is in reality younger than theory predicts.
In addition, any future human exploration of the Moon will involve supply structures, rockets, and other equipment being parked on the surface for long periods of time, even if living quarters are underground.
Knowing the present-day rate of impacts will be important in planning to protect equipment left on the surface.
In the future work, the Lunar Reconnaissance Orbiter Camera will continue taking images to verify the discovery and firm up the actual impact rate.
News source: Arizona State University.
Figure legend: This Knowridge.com image is credited to NASA/GSFC/ Arizona State University.