Difference between revisions of "September 21, 2011"

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<em>image from LRO [http://target.lroc.asu.edu/da/qmap.html Quick Map]</em><br />
 
<em>image from LRO [http://target.lroc.asu.edu/da/qmap.html Quick Map]</em><br />
 
<br />
 
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I noticed this elusive feature in [http://lpod.wikispaces.com/September+20%2C+2011 two] [http://lpod.wikispaces.com/September+12%2C+2011 recent] LPODs - did you? Between Eudoxus (left) and Lacus Mortis (mostly out of view to the right)
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I noticed this elusive feature in [http://www2.lpod.org/wiki/September_20,_2011 two] [http://www2.lpod.org/wiki/September_12,_2011 recent] LPODs - did you? Between Eudoxus (left) and Lacus Mortis (mostly out of view to the right)
 
is the remnant of a likely old crater about 75 km wide. It has been filled in with ejecta from Imbrium, Eudoxus and perhaps the Lacus  
 
is the remnant of a likely old crater about 75 km wide. It has been filled in with ejecta from Imbrium, Eudoxus and perhaps the Lacus  
 
Mortis crater. It is nearly completely covered, with only pieces of its rim rising above the debris. If it were a fresh crater the fill must be  
 
Mortis crater. It is nearly completely covered, with only pieces of its rim rising above the debris. If it were a fresh crater the fill must be  

Latest revision as of 08:37, 28 October 2018

Before And Way After

LPOD-Sept21-11.jpg
image from LRO Quick Map

I noticed this elusive feature in two recent LPODs - did you? Between Eudoxus (left) and Lacus Mortis (mostly out of view to the right) is the remnant of a likely old crater about 75 km wide. It has been filled in with ejecta from Imbrium, Eudoxus and perhaps the Lacus Mortis crater. It is nearly completely covered, with only pieces of its rim rising above the debris. If it were a fresh crater the fill must be 4 to 5 km deep. I called it an old crater, and it is probably older than 3.8 b.y., Imbrium's age, but it may have been quite fresh looking when inundated so that it's ageing was instantaneous. Consdiering that maria cover about 17% of the nearside, and thick basin ejecta may have buried another 5-10%, there have been many lunar craters that have long since been erased. A few like this are relicts of another time.

Chuck Wood

Related Links
Rükl plates 13 & 14


Yesterday's LPOD: Sequencing

Tomorrow's LPOD: A Modelers Moon


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