Repeating moonquakes on Moon found to be caused by remaining sections of Apollo 17’s LM

Scientists reviewing the archive seismic data produced by the seismometers placed on the Moon by the Apollo missions have discovered that repeating small moonquakes in that data were actually caused by base of Apollo 17’s Lunar Module (LM) that provided a launchpad for the part of the LM that lifted the astronauts off the Moon.

Triangulating the origin of the mystery quakes, researchers surprisingly realized they came from the Apollo 17 lunar lander base, which expands and vibrates each morning as it becomes heated by the sun.

“Every lunar morning when the sun hits the lander, it starts popping off,” Allen Husker, a Caltech research professor of geophysics who worked on the project, said in a statement. “Every five to six minutes another one, over a period of five to seven Earth hours. They were incredibly regular and repeating.”

That the extreme range of temperatures experienced by the LM could cause detectable quakes as the LM base expanded suggests strongly how difficult it is for a spacecraft to survive the lunar night lasting 14 Earth days. For all we know, that base has now literally fallen apart due to these stresses. This in turn suggests it is highly unlikely that India’s Pragyan rover will come back to life when the sun rises on September 22, 2023.

Remembering Apollo 17, fifty years after the last manned mission to the Moon

LRO oblique view of Apollo 17 landing site
Click for full image.

Link here.

The article comes from the Lunar Reconnaissance Orbiter (LRO) science team, and includes a number of LRO photos of the landing site, including the oblique annotated image to the right, reduced to post here. As the article notes:

The Apollo 17 crew was the last of an era in human space exploration and the last to set foot on the Moon. Fifty years later, the landing sites, hardware, and footsteps remain delicately preserved on the lunar surface. Join the LRO team as we commemorate their inspiring achievements with additional images, research, maps, interactive sites, and a dedicated video. LRO continues to image the Apollo sites whenever possible, under multiple lighting conditions, and combine these images into interactive sites, like the Apollo 17 Temporal Traverse. The Lunar QuickMap 3D tool can be used to preview the Apollo landing sites and search for LROC images of the areas. For downloadable maps of the Taurus-Littrow Valley, visit the Map Sheets section on our downloads page here. Finally, the Apollo 17 fiftieth anniversary video below presents highlights of the mission with landing site views reconstructed using LROC images and topography.

I have embedded that video below. It does a marvelous job summarizing this mission, which in many ways remains the most daring human exploration mission since Columbus dared cross an ocean in a tiny ship only slightly larger than many lifeboats.
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The Taurus-Littrow valley

Taurus-Littrow Valley
Click for full image.

It might not be Apollo 11, but during this 50th anniversary week of that mission, why not look at where the last Apollo 17 crew landed, in the middle of the Taurus-Littrow valley, as shown on the right in a Lunar Reconnaissance Orbiter (LR) image released by the LRO science team in 2018.

The image illustrates how ambitious NASA had become by this last Apollo mission. The Apollo 11 site was chosen because it was flat with as few risks as possible. By Apollo 17, the Apollo engineers and astronauts were quite willing to drop the LM down into this valley between gigantic mountains. Granted, the valley was more than 400 miles wide, but considering the risks of every Apollo flight, the choice was daring to say the least.

Taurus-Littrow also has a cluster of craters believed to have been formed by material flung out from the formation of 86-kilometer-wide Tycho crater about 100 million years ago. Tycho is 2250 kilometers from Taurus-Littrow, but the impact that formed it was violent enough that it cast material far across the Moon.

Nor is this location the most spectacular on the Moon. In fact, considering that all the manned and unmanned missions in total have probably covered less ground than a New York cab driver does in a single day, we have seen almost nothing there.

Another Google Lunar X-Prize team secures launch contract

Part Time Scientists, one of the teams competing for the Google Lunar X-Prize, has secured a launch contract through launch rideshare broker Spaceflight Inc.

Their rover will launch as a secondary payload. It is the broker’s job to secure that slot.

PTScientists plans to land its rovers in the moon’s Taurus-Littrow valley, the last place humans set foot on the lunar surface in December 1972, in the hopes of getting a closer look at how the Apollo moon buggy has survived over the past four and a half decades in the extreme temperatures and inhospitable conditions on the moon. “There is a reason we have chosen the Apollo 17 landing site,” said Karsten Becker, PTScientists electronics head, said in a call with reporters on Tuesday. “That is because the Taurus-Littrow valley is geographically very interesting — that is why it was chosen for Apollo 17 — but it is also a very-well documented site. There are many pictures where you can see that it is very flat, and that there are not that many stones laying around.”

The landing site has been chosen to be within reach of the Apollo 17 site, but not so close that it could risk damage to the NASA preservation heritage area. “We want to land 3 to 5 kilometers [2 to 4 miles] away from the [Apollo 17] landing site,” said Becker.

This team is now the fourth X-Prize team to secure a launch contract. All are hoping to launch within the next two years.