In a span of millions of years, Earth's constant gravitational forces are apparently changing the moon's shape, which only became obvious to NASA scientists recently.
During the past six years, NASA's Lunar Reconnaissance Orbiter along with its suite of highly advanced cameras have taken images of the lunar surface at high resolution quality. In the course of this survey mission, where it is about three fourths completed, NASA mission scientists have already discovered 3,000 cliffs on the surface called "lobate scarps".
These cliffs are formed due to a result of tectonic fracturing as the moon's warm core continues to transform and transition into a cooler temperature. When the lunar core cools, it also shrinks, the moon's crust becomes deformed and crinkled.
Upon closer examination, researchers found out that these tectonic features possess an odd symmetry. If this global contraction is solely responsible for the scarp formations, the fractures should have been sporadic or arranged in a random manner in their positioning and alignment.
However, according to Thomas Watters of the National Air and Space Museum, this is not what we found on the moon. There is a pattern that exists regarding the orientation of these faults in the thousands, suggesting that another activity is influencing these formations which is affecting the moon on a global scale, similar to "massaging" and realigning these formations.
Watters and his team analyzed and examined these formations to the Earth's gravitational pull and its directions to the moon's scattered faults and its alignment with each other, discovering in the process a distinct link with each other.
According to co-author of the study, LRO scientist, Mark Robinson from the Arizona State University, during the early stages of the mission, it has been suspected that tidal forces were crucial in the formation of these tectonic features however we do not have enouch data coverage yet to make any conclusions.
With these new NAC (Narrow Angle Camera) images along with more appropriate lighting of more than half of the lunar surface, these structural patterns are beginning to come into focus. Scientists now believe that the moon's contractions are causing many weaknesses, breaking the lunar crust into crinkles, as the Earth's gravitational forces stretch these faults in angles that are arranged in a distinct pattern.
According to LRO project scientist, John Keller, with this new LRO technology, the team has been able to study the moon in extreme detail that has not yet been done before in any body in the solar system. This new LRO data set unravels the important processes yet invisible ones occuring on the moon right now.
This new study is published in the journal, Geology.