Difference between revisions of "December 19, 2011"

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<em>left: image from LRO WAC mosaic, and right: close-up of Kies A from LRO WAC [http://target.lroc.asu.edu/da/qmap.html Act-REACT Quick Map]</em><br />
 
<em>left: image from LRO WAC mosaic, and right: close-up of Kies A from LRO WAC [http://target.lroc.asu.edu/da/qmap.html Act-REACT Quick Map]</em><br />
 
<br />
 
<br />
While looking at the wonderful nomenclature [http://lpod.wikispaces.com/December+4%2C+2011 map] Maurice Collins constructed with the LRO WAC mosaic I noticed a strange curved ridge  
+
While looking at the wonderful nomenclature [http://www2.lpod.org/wiki/December_4,_2011 map] Maurice Collins constructed with the LRO WAC mosaic I noticed a strange curved ridge  
 
tangent to Kies A. It immediately reminded me of a similar curved ridge or septum between [http://www.lpod.org/?m=200611 Plato K and KA.] This latter case is explained  
 
tangent to Kies A. It immediately reminded me of a similar curved ridge or septum between [http://www.lpod.org/?m=200611 Plato K and KA.] This latter case is explained  
 
as being created by converging ejecta from two simultaneously formed craters, but Kies A is just a single crater, although its shape is non-round. So I found a higher Sun LROC WAC view from the Quick Map - thanks ASU/NASA for two different mosaics! - that doesn't suggest  
 
as being created by converging ejecta from two simultaneously formed craters, but Kies A is just a single crater, although its shape is non-round. So I found a higher Sun LROC WAC view from the Quick Map - thanks ASU/NASA for two different mosaics! - that doesn't suggest  
 
two almost completely overlapping simulataneous craters. There is a small scallop on the northeast side where a collapse removed a small  
 
two almost completely overlapping simulataneous craters. There is a small scallop on the northeast side where a collapse removed a small  
 
bite from the rim. Then I remembered a second case of a similar single crater arc at Cauchy. Cauchy is a perfectly normal circular crater so
 
bite from the rim. Then I remembered a second case of a similar single crater arc at Cauchy. Cauchy is a perfectly normal circular crater so
the curved ridge does not require an unusual crater to form. I [http://lpod.wikispaces.com/May+31%2C+2009 wonder] if an oblique impact could produce such a curved septum? Neither  
+
the curved ridge does not require an unusual crater to form. I [http://www2.lpod.org/wiki/May_31,_2009 wonder] if an oblique impact could produce such a curved septum? Neither  
 
Cauchy nor Kies A is young enough to preserve rays to provide evidence for non-vertical impacts. Danny Caes had actually mentioned both  
 
Cauchy nor Kies A is young enough to preserve rays to provide evidence for non-vertical impacts. Danny Caes had actually mentioned both  
 
Kies A and Cauchy in an LPOD comment in 2009 and he wondered if there were more of them, which is still a good question. Finding more
 
Kies A and Cauchy in an LPOD comment in 2009 and he wondered if there were more of them, which is still a good question. Finding more

Latest revision as of 08:25, 28 October 2018

Single Crater Septum

LPOD-Dec19-11.jpg
left: image from LRO WAC mosaic, and right: close-up of Kies A from LRO WAC Act-REACT Quick Map

While looking at the wonderful nomenclature map Maurice Collins constructed with the LRO WAC mosaic I noticed a strange curved ridge tangent to Kies A. It immediately reminded me of a similar curved ridge or septum between Plato K and KA. This latter case is explained as being created by converging ejecta from two simultaneously formed craters, but Kies A is just a single crater, although its shape is non-round. So I found a higher Sun LROC WAC view from the Quick Map - thanks ASU/NASA for two different mosaics! - that doesn't suggest two almost completely overlapping simulataneous craters. There is a small scallop on the northeast side where a collapse removed a small bite from the rim. Then I remembered a second case of a similar single crater arc at Cauchy. Cauchy is a perfectly normal circular crater so the curved ridge does not require an unusual crater to form. I wonder if an oblique impact could produce such a curved septum? Neither Cauchy nor Kies A is young enough to preserve rays to provide evidence for non-vertical impacts. Danny Caes had actually mentioned both Kies A and Cauchy in an LPOD comment in 2009 and he wondered if there were more of them, which is still a good question. Finding more examples might lead to clues as to their origin.

Chuck Wood

Related Links
Rükl plate 53


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