Golfing with boulders on the Moon
Click for full resolution image.
Cool image time! The Lunar Reconnaissance Orbiter team this week released a beautiful image of boulder tracks rolling down the inside slope of 85-mile-wided Antoniadi crater on the far side of the Moon. The image above, cropped, reduced, and annotated to post here, shows these tracks.
The most obvious track is cool because the boulder almost made, as the scientists note, “a hole-in-one.”
Running from the outcrops to the rim of the partially buried crater is a track etched by a rolling boulder bigger than a bus. Perhaps a moonquake shook it loose. The boulder bounced and rolled toward the partially buried crater, plowing a path that is still visible through the loose material of the slope. When it reached the rim of the partially erased crater, its path curved and it slowed to a stop.
…Had it rolled just 75 meters more, the boulder might have plopped neatly into a 30-meter-diameter young impact crater on the floor of the partially erased crater.
The arrows I have added indicate two more less obvious boulder tracks. If you click on the full resolution image and zoom in you can also see another series of impressions in the middle of the photograph that look like a dotted line, suggesting they were left by a boulder bouncing down the slope.
The scattered of boulders in the floor of the small crater all likely came from the top of the big crater’s rim, which I show in the wider image below.
The box indicates the location of the image above.
While many things over the eons could caused these boulders to roll (moonquakes, erosion from the solar wind, other nearby impacts), a close look at the ground surrounding them does not show tracks emanating from most, suggesting they have been there a very long time, long enough for the surface reworking caused by the solar wind to have smoothed those tracks out.
The Moon is airless and mostly dead. The solar wind is incredibly weak. Any changes caused by it will take a lot of time. Consider the time required to smooth out those tracks. The mind boggles.
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.
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Click for full resolution image.
Cool image time! The Lunar Reconnaissance Orbiter team this week released a beautiful image of boulder tracks rolling down the inside slope of 85-mile-wided Antoniadi crater on the far side of the Moon. The image above, cropped, reduced, and annotated to post here, shows these tracks.
The most obvious track is cool because the boulder almost made, as the scientists note, “a hole-in-one.”
Running from the outcrops to the rim of the partially buried crater is a track etched by a rolling boulder bigger than a bus. Perhaps a moonquake shook it loose. The boulder bounced and rolled toward the partially buried crater, plowing a path that is still visible through the loose material of the slope. When it reached the rim of the partially erased crater, its path curved and it slowed to a stop.
…Had it rolled just 75 meters more, the boulder might have plopped neatly into a 30-meter-diameter young impact crater on the floor of the partially erased crater.
The arrows I have added indicate two more less obvious boulder tracks. If you click on the full resolution image and zoom in you can also see another series of impressions in the middle of the photograph that look like a dotted line, suggesting they were left by a boulder bouncing down the slope.
The scattered of boulders in the floor of the small crater all likely came from the top of the big crater’s rim, which I show in the wider image below.
The box indicates the location of the image above.
While many things over the eons could caused these boulders to roll (moonquakes, erosion from the solar wind, other nearby impacts), a close look at the ground surrounding them does not show tracks emanating from most, suggesting they have been there a very long time, long enough for the surface reworking caused by the solar wind to have smoothed those tracks out.
The Moon is airless and mostly dead. The solar wind is incredibly weak. Any changes caused by it will take a lot of time. Consider the time required to smooth out those tracks. The mind boggles.
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.
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