Space shocker: Earth's moon is shrinking, experiencing seismic activities

James Marshall
December 1, 2019

"Our efforts will include new work at NASA centers to provide the key technologies and scientific payloads needed for the lunar surface, adding to efforts already underway across the country". A fault scarp is an area where the ground in one area has moved vertically with respect to another as a result of geological processes like earthquakes.

The American space agency's Lunar Reconnaissance Orbiter (LRO) photographed the site 11 days after the attempted landing on April 11, on a region of the moon known as the Sea of Serenity, about 56 miles above the surface.

Earth's closest natural satellite could be producing powerful moonquakes as it cools and shrinks, according to a newly-published study. But a new analysis of Apollo-era data suggests these conclusions are inaccurate.

While most were recorded deep in the interior, 28 were traced to the crust, just 200 kilometres from the surface. Impact craters, another common lunar feature, can help geologists better date these "wrinkle ridges" and their importance in the moon's cooling and shrinking activity. "I think it is very attractive that, 50 years after Apollo, the Artemis program will carry the next man and the first woman to the moon". "It's quite likely that the faults are still active today".

"For me, these findings emphasize that we need to go back to the Moon", said Nicholas Schmerr, an assistant professor of geology at the University of Maryland and co-author of the paper.

Four seismometers had been placed on the Moon by the Apollo 11, 12, 14, 15, and 16 missions, the instruments collectively running between 1969 and 1977.

There have been a range of theories about what causes quakes, including meteorite collisions or gravitational forces exerted by the Earth and sun.

By looking at the size and location of the tremors, the algorithm estimates the epicenter of the moonquakes. "Such a young age raises the intriguing possibility that these thrust faults are now active", says Watters and colleagues in their paper. The Moon and Earth always tug on each other, but the stress on the faults is greatest when the Moon is at apogee, its farthest point from Earth.

Like the Earth, the Moon has a core, mantle, and crust, but the core of the Moon is much smaller and only partially liquid (approximately 40 percent of the lunar core is believed to have solidified). But the lunar faults, like Earth fault lines, are similar in that they're where pieces of the surface sometimes rub against each other, causing quakes that can reverberate throughout the planet. This shrinkage creates "wrinkles" on the Moon's skin, except the rock isn't flexible. This breakage results in thrust faults, where one section of crust is pushed up over an adjacent section. 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. Some of these images show landslides or boulders at the bottom of relatively bright patches on the slopes of fault scarps or nearby terrain.

'We're excited to be landing the first woman and next man on the surface of the Moon by 2024'.

Other reports by Click Lancashire

Discuss This Article