Who knew? You wouldn’t know to look at it, but the moon has decreased in size by about 150 feet over the past 4.5 billion years. Think of a rotting strawberry.
“Well, it’s just cooling off,” says Rice University Physics and Astronomy professor Dr. Patricia Reiff, simplifying the complex astrophysics involved.
Scientists revealed Monday that the moon’s cooling is causing it to get imperceptibly smaller and dry up into plates that bump into each other and create quakes. None of this is earth-shattering, according to Thomas Watters, the lead author of the study with the Smithsonian Institution’s National Air and Space Museum, but he says some of the quakes would register as high as a 5 on the Richter scale used on Earth. Think of a chocolate-covered strawberry, Dr. Reiff suggests. “If you had a chocolate-dipped strawberry and you let that strawberry rot, eventually that chocolate coating is going to crack as that strawberry inside shrinks, and that’s what we’re talking about.” It's as simple as that.
We can thank the NASA scientists at Johnson Space Center for having the insight during the Apollo years to leave behind seismic sensors which, when combined with current cutting-edge high-resolution imagery, have revealed the shrinkage. Dr. Reiff says there are several ongoing studies continuing from Apollo days and finds the latest discovery evidence of reasons to return: there is still so much we don’t know.
This Saturday night we’ll have a full Blue Moon, this one being a regular seasonal blue moon.
It won’t be blue, but just a tad bit smaller.