Moonquakes are causing the moon to shrink over time


Seismic activity on the Moon is causing the satellite's surface to wrinkle "like a raisin" giving ride to steep step-like cliffs known as scarps.

As the moon shrinks, it gets wrinkled, which then forms "thrust faults" and results in one section of the surface crust pushing up over another crust.

NASA says the moon is shrinking and it may be creating so-called "moonquakes".

Only 12 humans, all male, have ever walked on the moon and they were all American, according to Bettina Inclán, NASA Communications Director.

Watters says that the quakes can be strong, around a five on the Richter scale, according to the NASA statement. These faults resemble small stair-shaped cliffs, or scarps, when seen from the lunar surface; each is roughly tens of yards high and a few miles long.

Astronaut James Irwin, lunar module pilot, gives a military salute while standing beside the USA flag during Apollo 15 lunar surface extravehicular activity (EVA) at the Hadley-Apennine landing site on the moon, August 1, 1971.

Using the revised location estimates from their new algorithm, the researchers found that the epicenters of eight of the 28 shallow quakes were within 19 miles of faults visible in the LRO images. At least eight of the quakes occurred due to activity along the faults.

Some of the quakes also happened during a point in the moon's orbit when it was farthest from Earth, indicating that the tidal stress of Earth's gravity could have contributed to stress on the moon's crust.

To check their findings, researchers ran 10,000 simulations to see if this amount of quakes near faults can be coincidental, however, they found the chances are less than 4 per cent.

This prominent thrust fault is one of the thousands discovered on the moon by NASA's Lunar Reconnaissance Orbiter (LRO).

"Fifty years after Apollo, the Artemis program will carry the next man and first woman to the moon", said Bridenstine during a press call. If so, "the Apollo seismometers recorded the shrinking moon and the moon is still tectonically active", he said, calling the results "amazing". The relatively small size of the Moon's fault scarps is in line with the more subtle contraction expected from a partially molten scenario. This rules out the possibility of asteroid impacts or rumblings from the moon's interior. Since it began operation a decade ago, over 3,500 of these faults have been identified by the LRO.

The increased funding request, announced by President Donald Trump on Twitter, comes almost two months after Vice President Mike Pence declared the objective of shortening by four years NASA's previous timeline for putting astronauts back on the moon for the first time since 1972.

He said: "Our analysis gives the first evidence that these faults are still active and likely producing moonquakes today as the Moon continues to gradually cool and shrink".

"For me, these findings emphasize that we need to go back to the moon", said researcher Nicholas Schmerr of the University of Maryland.

The announcement comes about six weeks after US Vice President Mike Pence called for an accelerated program to return humans to the lunar surface for the first time since the last Apollo lunar landing in 1972. With a larger network of modern seismometers, we could make huge strides in our understanding of the Moon's geology. A team of researchers have now reanalyzed the data along with detailed images captured by the Lunar Reconnaissance Orbiter, which was launched in 2009.

Lunar science: $90 million to enable increased robotic exploration of the moon's polar regions in advance of a human mission.