Moon shrinking because of seismic activity


Interesting report by Yaron Steinbuch of the New York Post on the scientific discovery that our Moon is getting smaller…and Jackie Gleason had nothing to do with it:

Seismic activity on the moon is causing it to shrink and wrinkle “like a raisin,” according to an earth-shattering new study.

For the first time, scientists have connected moon-quake data to the changing lunar landscape, showing that our satellite is tectonically active, according to the study published Monday in Nature Geoscience.

The jolts these days are strong enough to have caused Neil Armstrong to lose his footing as he made his “one small step” on the Sea of Tranquility 50 years ago, the research suggests.

A team of scientists examined data from NASA’s Lunar Reconnaissance Orbiter and compared it to the location of tremors recorded during the Apollo program in the 1960s and 1970s, Newsweek reported.

On Dec. 12, 1972, Gene Cernan parked his moon buggy in a valley named Taurus-Littrow, where a slumping escarpment — nicknamed the “Lee-Lincoln scarp” – was observed on a hill in the distance, Scientific American reported.  

Fellow astronaut Harrison “Jack” Schmitt, a geologist, remarked that the scarp had formed after the hill was raised when something deep within the lunar surface had stirred.

Seismic instruments left by the American explorers showed that the moon experienced occasional quakes — mostly related to internal cooling and tidal forces from Earth’s gravity.

When the LRO began snapping high-resolution images in 2009, scientists realized the moon had numerous scarps like Lee-Lincoln.

“If you’re interested in an outpost, and you expect to be there for some time, you need to be mindful that if you are too close to one of these faults, your structure is going to be shaking,” Tom Watters, a geophysicist at the Smithsonian Institution’s National Air and Space Museum, told Scientific American.

In 2012, Watters figured out that the scarps and related features formed quite recently, perhaps as recently as 50 million years ago.

“We were all converging on the idea that these things are really young. That always leads you to the intriguing possibility that maybe these things are still active, and maybe these faults are showing us current tectonic activity on the moon,” Watters said.

The scientists discovered that the moon had been shrinking as its interior cooled down and may be getting even smaller as its crust becomes brittle– a bit like what happens to a grape as it dries out to become a raisin.

More than 3,500 of the faults have been identified by the LRO.  Those that appear brighter indicate freshly exposed rock, suggesting an event like a “moonquake.”

  • 05/13/2019
  • Yaron Steinbuch