NASA recently conducted a study in preparation for its Artemis mission, which has revealed some fascinating changes taking place on the moon. The moon has been a constant presence in the night sky, symbolizing a timeless connection with Earth. This study, however, tells a story of a shrinking moon, gradually contracting in size over millions of years.
According to the study published on January 25, the moon has diminished by more than 150 feet in circumference due to the gradual cooling of its core. As it continues to shrink, faults are formed, leading to moonquakes, which could pose challenges for future human exploration, particularly in planned landing areas near the Lunar South Pole.
The research, involving scientists from NASA, the Smithsonian, Arizona State University, and The University of Maryland, utilized data from the Lunar Reconnaissance Orbiter (LRO) to identify thousands of relatively small, young thrust faults widely spread across the moon’s surface.
Lead author Tom Watters from the Smithsonian Institution explained, “Our modelling suggests that shallow moonquakes capable of producing strong ground shaking in the south polar region are possible from slip events on existing faults or the formation of new thrust faults,” adding that “the global distribution of young thrust faults, their potential to be active, and the potential to form new thrust faults from ongoing global contraction should be considered when planning the location and stability of permanent outposts on the moon.”
The contraction is attributed to the cooling of the moon’s hot interior and tidal forces exerted by Earth, resulting in a global shrinking process. This intriguing process is likened to the wrinkling of a grape during its transformation into a raisin. However, unlike a grape, the moon’s brittle surface causes faults to form as sections of the crust push against each other.
Furthermore, while shallow moonquakes occur at a depth of about 100 miles within the moon’s crust, they differ from earthquakes as they can endure for hours and even an entire afternoon, unlike the brief moments of tremors experienced on Earth.
