This shrinkage creates "wrinkles" on the Moon's skin, except the rock isn't flexible.
Back in 1972, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt ascended to one of the Moon's cliffs called the Lee-Lincoln fault scarp as part of their mission to measure the seismic activities of our lunar neighbor.
Astronauts have placed seismometers on the moon over a series of past missions. Four of these seismometers recorded 28 shallow moonquakes from 1969 to 1977.
As a result, researchers were able to "tentatively attribute" the recorded quakes to the faults.
"We've got these possibly active faults on the Moon, which means it isn't this dead body", Tom Watters, study first author from the Center for Earth and Planetary Studies at the Smithsonian Institution in Washington, DC, told Gizmodo. They found it is less than 4 percent.
"We found that a number of the quakes recorded in the Apollo data happened very close to the faults seen in the [NASA's Apollo and Lunar Reconnaissance Orbiter missions] LRO imagery", Nicholas Schmerr, an assistant professor of geology at the University of Maryland, said in a statement. The Lunar Reconnaissance Orbiter Camera (LROC) has imaged over 3,500 of the fault scarps. Twenty-eight deeper quakes, however, were unaccounted for.
The space agency wants to establish "sustainable missions by 2028" - taking what they learn from the moon and applying it to reaching Mars.
The LRO images also revealed surface features that support the theory that the Moon continues to be active. A large landslide on South Massif that covered the southern segment of the Lee-Lincoln scarp is further evidence of possible moonquakes generated by fault slip events.
"It's really remarkable to see how data from almost 50 years ago and from the LRO mission has been combined to advance our understanding of the Moon while suggesting where future missions intent on studying the Moon's interior processes should go", said LRO Project Scientist John Keller of NASA's Goddard Space Flight Center in Greenbelt, Maryland.
"We conclude that the proximity of moonquakes to the young thrust faults together with evidence of regolith disturbance and boulder movements on and near the fault scarps strongly suggest the Moon is tectonically active", the study's abstract reads. As the Moon cools, it shrinks - and the Moon's diameter has shrunk approximately 150 feet over the past several hundred million years, according to NASA.
The Moon isn't the only world in our solar system experiencing some shrinkage with age.
The New York Times' Robin George Andrews reports that there were explanations for numerous shakes. Meteorite collisions caused some, others were attributed to Earth's gravitational pull and others were caused by huge 500-degree temperature changes on the moon when night turns to day. "The moon's formation generated a lot of heat, and it has been gradually cooling off ever since". Such tracks would be erased relatively quickly, in terms of geologic time, by the constant rain of micrometeoroid impacts on the Moon.
"The first woman will be an American on the surface of the moon in five years", Bridenstine said in April during the Space Symposium conference in Colorado Springs.
In March, Vice President Mike Pence prepared the ground to speed up a lunar landing mission, telling the National Space Council that the U.S. will return astronauts to the moon within five years "by any means necessary", and that "mission success will require more than just money".
"Under my Administration, we are restoring @NASA to greatness and we are going back to the Moon, then Mars", Trump tweeted on Monday.
In addition to the groundbreaking research, NASA hopes that this new exploration will inspire the next generation of scientists.