New Photos from NASA’s LRO Program Shows Possibility of Shrinking Moon

A team sorting and analyzing the images received from the Lunar Reconnaissance Orbiter (LRO) craft developed by NASA say that a special type of cliffs they’re examining may indicate that the moon has shrank more recently than previously thought.

The moon formed in a hot environment, with radioactive decay and constant collisions with meteors and asteroids. This led scientists to believe that the moon shrank as it cooled. The recent images show cliffs, known as lobate scarps, that have likely formed as little as 100 million years ago. That may seem like a long time, but the moon is four billion years old. The previous research supported the idea that the moon shrank during it’s early history, but this is the first proof of more recent geological activity.

The cliffs, or scarps, only reach about 300 ft. in height and a few miles in length at the most. Several cut across small craters on the moon’s surface, which have formed recently. This is the basis for the hypothesis that these scarps are relatively recent developments. The scarps themselves appear sharp from the images, and show few signs of the weathering that older formations have. Moonquakes have been recorded by probes. Seismological activity could indicate that cooling is still occuring.

These cliffs were photographed first by the Apollo missions, but this is the first image to show they are a global phenomenon. Stress fractures and thrusts from the contracting surface of a cooling moon are the best explanation say scientists at NASA.

NASA hopes that the research team will be able to use the LRO’s high quality images to begin working on a global map of the moon. This would help identify if the pull of the Earth has affected the orientation or location of the scarps, and would allow for a better understanding of the moon’s surface on a global level.

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