Triple impact on Moon
Cool image time! A new image release from Lunar Reconnaissance Orbiter (LRO) takes a look at the impact process that created the crater Messier and its neighbor crater Messier A. The photo to the right, cropped to post here, shows both craters.
Take a close look at Messier A. It is actually a double crater itself. From the release:
Messier A crater, located in Mare Fecunditatis, presents an interesting puzzle. The main crater is beautifully preserved, with a solidified pond of impact melt resting in its floor. But there is another impact crater beneath and just to the west of Messier A. This more subdued and degraded impact crater clearly formed first.
Did these three craters happen as separate events. According to the data, it appears no. Instead, they might have all been part of a single rain of asteroids, all occurring in seconds.
Messier crater is extremely elongated, which is an indication that it formed when an impactor struck the surface at a very shallow angle (less than 15° from the surface). Its high-reflectance rays stretch to the north and south, caused by ejecta that was emplaced asymmetrically, another sign of a low-angle impact. Messier crater’s presence suggests that each of these impact craters may be related, forming when an impactor broke up, and struck the surface as three pieces instead of just one.
…Another theory (the “decapitated” impactor scenario) suggests that the impactor could have actually split apart after hitting the surface at the Messier impact site, with a portion of the impactor continuing downrange to form Messier A crater.
Try to imagine the event that created these 9-mile-wide craters, especially the second scenario, where the asteroid zooms in at a low angle, hits the ground, its top half breaking off into two pieces that smash into the ground, bam-bam, just to the west.
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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:
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Cool image time! A new image release from Lunar Reconnaissance Orbiter (LRO) takes a look at the impact process that created the crater Messier and its neighbor crater Messier A. The photo to the right, cropped to post here, shows both craters.
Take a close look at Messier A. It is actually a double crater itself. From the release:
Messier A crater, located in Mare Fecunditatis, presents an interesting puzzle. The main crater is beautifully preserved, with a solidified pond of impact melt resting in its floor. But there is another impact crater beneath and just to the west of Messier A. This more subdued and degraded impact crater clearly formed first.
Did these three craters happen as separate events. According to the data, it appears no. Instead, they might have all been part of a single rain of asteroids, all occurring in seconds.
Messier crater is extremely elongated, which is an indication that it formed when an impactor struck the surface at a very shallow angle (less than 15° from the surface). Its high-reflectance rays stretch to the north and south, caused by ejecta that was emplaced asymmetrically, another sign of a low-angle impact. Messier crater’s presence suggests that each of these impact craters may be related, forming when an impactor broke up, and struck the surface as three pieces instead of just one.
…Another theory (the “decapitated” impactor scenario) suggests that the impactor could have actually split apart after hitting the surface at the Messier impact site, with a portion of the impactor continuing downrange to form Messier A crater.
Try to imagine the event that created these 9-mile-wide craters, especially the second scenario, where the asteroid zooms in at a low angle, hits the ground, its top half breaking off into two pieces that smash into the ground, bam-bam, just to the west.
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.
Excellent cool image Bob! How cool it would be to be a bystander ( at a safe distance!)
Carolina Bays!!
I was under the impression that all impact craters are round no matter the angle of impact. It has to do with the shock-wave rebounding off of the larger body blowing out material in a circle.
That said why is that one crater (b) oblong? Could it also be a simultaneous double impact of nearly identical objects?