Is the moon all it’s cracked up to be? Yes, and then some. New analysis of the lunar surface reveals that it’s far more fractured than once thought.
Since the moon formed 4.3 billion years ago, asteroid impacts have scarred its face with pits and craters. But the damage goes far deeper than that, with cracks extending to depths of 12 miles (20 kilometers), researchers recently reported.
Though the moon’s craters have been well-documented, scientists previously knew little about the upper region of the moon’s crust, the megaregolith, which sustained the bulk of the damage from space rock bombardment.
In the new study, computer simulations revealed that impacts from single objects could fragment the lunar crust into blocks about 3 feet (1 meter) wide, opening surface cracks that extend for hundreds of kilometers. This suggests that much of the fracturing in the megaregolith could have come from single, high-speed impacts, leaving the crust “thoroughly fractured” early in the moon’s history.
These findings helped to address questions raised by NASA’s Gravity Recovery and Interior Laboratory (GRAIL), a mission that sent twin spacecraft to the moon in 2011 to create the most detailed lunar gravity map to date.
Data gathered by GRAIL showed that the moon’s crust was far less dense than expected, Sean Wiggins, lead author of the new study and a doctoral candidate with the Earth, Environmental and Planetary Sciences Department at Brown University in Rhode Island, told Live Science.
Wiggins and his colleagues suspected that ancient impacts could have substantially fractured the lunar surface, “adding porosity and therefore lowering the density,” he said.