Yutu-2 data suggests Moon’s far side is “bombarded more frequently” than the near side
The uncertainty of science: According to a new paper, based on ground-penetrating radar data obtained by China’s Yutu-2 rover on the far side of the Moon, scientists now think that the Moon’s more heavily cratered far side is that way because it actually gets bombarded more frequently than the near side.
From the paper’s abstract:
The Lunar Penetrating Radar (LPR) onboard Yutu-2 can transmit electromagnetic pulses to detect the lunar subsurface structure and properties of the regolith. The relative permittivity, loss tangent and TiO2+FeO content of lunar regolith materials at landing site are constrained with LPR data in this paper. The results indicate that the farside may be bombarded more frequently, leading to different regolith accumulation rates on the lunar nearside vs. farside. [emphasis mine]
The data was accumulated during the rover’s first five months on the surface, during those five lunar days. It found that the regolith at the landing site was about 39 feet thick, much thicker than found at the landing site for Yutu-1 on the Moon’s near side. The difference was partly expected because of the nature of the different locations, but combined with other factors the scientists concluded that a higher bombardment rate on the far side would also help explain the difference.
To put it mildly, this conclusion is uncertain. We only have one data point on the far side, and only a few more on the near side. At the same time, the conclusion is somewhat an example of science discovering the obvious. The very first images of the Moon’s far side, taken The Soviet Union’s Luna 3 lunar probe in 1959, showed the surface much more heavily cratered than the near side, with far less areas of smooth mare. Numerous mapping missions since have confirmed that impression.
And it is also intuitive to come to this conclusion. The near side always faces the Earth, which likely acts to intercept many of the type of meteorite hits that reach the Moon’s far side.
This conclusion however is still intuitive, and an honest scientist will not trust it. That this result from Yutu-2 appears to confirms it is therefore nice.
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The uncertainty of science: According to a new paper, based on ground-penetrating radar data obtained by China’s Yutu-2 rover on the far side of the Moon, scientists now think that the Moon’s more heavily cratered far side is that way because it actually gets bombarded more frequently than the near side.
From the paper’s abstract:
The Lunar Penetrating Radar (LPR) onboard Yutu-2 can transmit electromagnetic pulses to detect the lunar subsurface structure and properties of the regolith. The relative permittivity, loss tangent and TiO2+FeO content of lunar regolith materials at landing site are constrained with LPR data in this paper. The results indicate that the farside may be bombarded more frequently, leading to different regolith accumulation rates on the lunar nearside vs. farside. [emphasis mine]
The data was accumulated during the rover’s first five months on the surface, during those five lunar days. It found that the regolith at the landing site was about 39 feet thick, much thicker than found at the landing site for Yutu-1 on the Moon’s near side. The difference was partly expected because of the nature of the different locations, but combined with other factors the scientists concluded that a higher bombardment rate on the far side would also help explain the difference.
To put it mildly, this conclusion is uncertain. We only have one data point on the far side, and only a few more on the near side. At the same time, the conclusion is somewhat an example of science discovering the obvious. The very first images of the Moon’s far side, taken The Soviet Union’s Luna 3 lunar probe in 1959, showed the surface much more heavily cratered than the near side, with far less areas of smooth mare. Numerous mapping missions since have confirmed that impression.
And it is also intuitive to come to this conclusion. The near side always faces the Earth, which likely acts to intercept many of the type of meteorite hits that reach the Moon’s far side.
This conclusion however is still intuitive, and an honest scientist will not trust it. That this result from Yutu-2 appears to confirms it is therefore nice.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
I was under the impression that the mare on the near side was caused by tidal forces from Earth when the Moon was much younger, much closer to Earth, and had a molten liquid interior. This changed the evolution of the Moon’s crust and mantle in such a way that large oceans of lava remained on the near side longer through the early heavy bombardment than the far side where the crust solidified earlier which preserved scarring from collisions much more readily.
Of course, I could be mistaken.
I’m not sure how long it took for the Moon to become tidally locked to the Earth, but that would largely explain to me why the ‘outside’ facing half of the Moon would get more bombardment. It is effectively acting as the shield (or more like a cosmic buckler) for objects headed for the Earth.