A lunar crater wall two miles high
Cool image time! Considering this week is the 50th anniversary of the Apollo 11 lunar landing, it seems appropriate to show some cool images from the Moon.
Today the Lunar Reconnaissance Orbiter (LRO) science team released a spectacular oblique image of Giordano Bruno crater. The image on the right is cropped and very significantly reduced to post here. It looks across the crater, with the near rim across the bottom of the picture and the wall of the far rim filling the photograph’s top half.
That wall is what makes this image cool. It is a cliff about 10,000 feet high, equaling almost two miles. Moreover, at its base is a now-solidified melt pool left over from the impact that made the crater.
Faster than a speeding bullet – or rather ten times faster than a speeding bullet – is a good starting point in terms of grasping the energy released in a typical impact event. That is, for a bullet approaching 2 kilometers in diameter! The pressure and heat that were released during the collision not only excavated a hole much larger than the impactor but also melted a tremendous amount the target rock. Melt was sprayed and sloshed on the forming crater walls where much of it flowed back, seeking the lowest point in the impact crater. From the LROC vantage point you can follow the path taken by impact melt as it flowed across the irregular floor, ponding in closed depressions, and some of it ultimately reaching the lowest point.
Below the fold is a much higher resolution section of this photograph, focused on the crater wall and the melt pool. I have still been forced to reduce the resolution somewhat to post it here. Along that cliff wall can be seen partial avalanches (the dark splotch near the center) as well boulder tracks with the boulders (probably larger than most houses) still visible as white spots at the wall’s base.
The scale here is difficult to imagine. This cliff wall is three times as high as The Abyss, the steepest single drop viewpoint along the south rim of the Grand Canyon.
![Giant rim wall of Giordiano Bruno crater](https://behindtheblack.com/wp-content/uploads/2019/07/M1258193408_LRmos.warp_.str01.crop30x24in_20190610_152109cropped.png)
Readers!
Every February I run a fund-raising drive during my birthday month. This year I celebrate my 72nd birthday, and hope and plan to continue writing and posting on Behind the Black for as long as I am able.
I hope my readers will support this effort. As I did in my November fund-raising drive, I am offering autographed copies of my books for large donations. Donate $250 and you can have a choice of the hardback of either Genesis: the Story of Apollo 8 or Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space. Donate $200 and you can get an autographed paperback copy of either. IMPORTANT! If you donate enough to get a book, please email me separately to tell me which book you want and the address to mail it to.
Please consider supporting my work here at Behind the Black. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID 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. Every one of those 2020 conclusions has turned out right.
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.
Cool image time! Considering this week is the 50th anniversary of the Apollo 11 lunar landing, it seems appropriate to show some cool images from the Moon.
Today the Lunar Reconnaissance Orbiter (LRO) science team released a spectacular oblique image of Giordano Bruno crater. The image on the right is cropped and very significantly reduced to post here. It looks across the crater, with the near rim across the bottom of the picture and the wall of the far rim filling the photograph’s top half.
That wall is what makes this image cool. It is a cliff about 10,000 feet high, equaling almost two miles. Moreover, at its base is a now-solidified melt pool left over from the impact that made the crater.
Faster than a speeding bullet – or rather ten times faster than a speeding bullet – is a good starting point in terms of grasping the energy released in a typical impact event. That is, for a bullet approaching 2 kilometers in diameter! The pressure and heat that were released during the collision not only excavated a hole much larger than the impactor but also melted a tremendous amount the target rock. Melt was sprayed and sloshed on the forming crater walls where much of it flowed back, seeking the lowest point in the impact crater. From the LROC vantage point you can follow the path taken by impact melt as it flowed across the irregular floor, ponding in closed depressions, and some of it ultimately reaching the lowest point.
Below the fold is a much higher resolution section of this photograph, focused on the crater wall and the melt pool. I have still been forced to reduce the resolution somewhat to post it here. Along that cliff wall can be seen partial avalanches (the dark splotch near the center) as well boulder tracks with the boulders (probably larger than most houses) still visible as white spots at the wall’s base.
The scale here is difficult to imagine. This cliff wall is three times as high as The Abyss, the steepest single drop viewpoint along the south rim of the Grand Canyon.
Readers!
Every February I run a fund-raising drive during my birthday month. This year I celebrate my 72nd birthday, and hope and plan to continue writing and posting on Behind the Black for as long as I am able.
I hope my readers will support this effort. As I did in my November fund-raising drive, I am offering autographed copies of my books for large donations. Donate $250 and you can have a choice of the hardback of either Genesis: the Story of Apollo 8 or Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space. Donate $200 and you can get an autographed paperback copy of either. IMPORTANT! If you donate enough to get a book, please email me separately to tell me which book you want and the address to mail it to.
Please consider supporting my work here at Behind the Black. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID 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. Every one of those 2020 conclusions has turned out right.
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.
This reminds me of the stats for the earth. If the earth was round (no bumps “mountains”) the water would be nearly 2 miles deep. My Everest is nearly thrice this above sea level.
The outstanding aspect here is that this 10,000ft relief was caused by an impact.
WOW
What is really amazing is how quickly these craters are excavated! Even that largest impacts are ‘over’ in a few minutes…
https://www.lpi.usra.edu/exploration/training/resources/impact_cratering/