Difference between revisions of "De Morgan"

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[[Image:de-Morgan-Clem.jpg|external image de-Morgan-Clem.jpg]]<br />
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[[Image:De-Morgan-Clem.jpg|external image de-Morgan-Clem.jpg]]<br />
 
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[[Image:de-Morgan-closeup-clem.jpg|external image de-Morgan-closeup-clem.jpg]]<br />
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[[Image:De-Morgan-closeup-clem.jpg|external image de-Morgan-closeup-clem.jpg]]<br />
 
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[http://lpod.org/coppermine/displayimage.php?pid=4401&fullsize=1 [[Image:normal_demorgan-large.jpg|external image normal_demorgan-large.jpg]]]<br />
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[http://lpod.org/coppermine/displayimage.php?pid=4401&fullsize=1 [[Image:Normal_demorgan-large.jpg|external image normal_demorgan-large.jpg]]]<br />
 
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'''Left:''' ''[http://lpod.org/coppermine/displayimage.php?pos=-2646 Clementine]'' Under high Sun, '''de Morgan''' is lost (the small unbright crater in the middle of the frame) amid the dark rays of [[Dionysius|Dionysius]] and the crisp bright walled [[Cayley|Cayley]], immediately above '''de Morgan'''. '''Middle''': ''[http://lpod.org/coppermine/displayimage.php?pos=-2647 Clementine closeup]'' '''Right:''' ''[http://www.lpi.usra.edu/resources/lunarorbiter/images/preview/4090_h1.jpg Lunar Orbiter LO-4090-H1]'' image from the [http://www.lpi.usra.edu/ Lunar & Planetary Institute].<br /> <br /> <div id="toc">
 
'''Left:''' ''[http://lpod.org/coppermine/displayimage.php?pos=-2646 Clementine]'' Under high Sun, '''de Morgan''' is lost (the small unbright crater in the middle of the frame) amid the dark rays of [[Dionysius|Dionysius]] and the crisp bright walled [[Cayley|Cayley]], immediately above '''de Morgan'''. '''Middle''': ''[http://lpod.org/coppermine/displayimage.php?pos=-2647 Clementine closeup]'' '''Right:''' ''[http://www.lpi.usra.edu/resources/lunarorbiter/images/preview/4090_h1.jpg Lunar Orbiter LO-4090-H1]'' image from the [http://www.lpi.usra.edu/ Lunar & Planetary Institute].<br /> <br /> <div id="toc">
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[[Clementine|Clementine]] provides an excellent view of this standard little simple crater. It has steep walls and a flat floor with two tiny hills as central peaks. '''de Morgan''''s walls are not nearly as bright as those of nearby [[Cayley|Cayley]], suggesting that the smaller crater is older. This is supported by noting that [[Cayley|Cayley]] truncates one of the dark rays from [[Dionysius|Dionysius]], whereas a piece of the dark ejecta seems to impinge on the western wall of '''de Morgan'''. But two other dark areas occur along the northern wall so perhaps this is just a buried pyroclastic layer - the same one that is the source of [[Dionysius|Dionysius]]' rays. <span class="membersnap">- tychocrater <small>Sep 26, 2007</small></span><br /> <br />  
 
[[Clementine|Clementine]] provides an excellent view of this standard little simple crater. It has steep walls and a flat floor with two tiny hills as central peaks. '''de Morgan''''s walls are not nearly as bright as those of nearby [[Cayley|Cayley]], suggesting that the smaller crater is older. This is supported by noting that [[Cayley|Cayley]] truncates one of the dark rays from [[Dionysius|Dionysius]], whereas a piece of the dark ejecta seems to impinge on the western wall of '''de Morgan'''. But two other dark areas occur along the northern wall so perhaps this is just a buried pyroclastic layer - the same one that is the source of [[Dionysius|Dionysius]]' rays. <span class="membersnap">- tychocrater <small>Sep 26, 2007</small></span><br /> <br />  
 
===Elger===
 
===Elger===
''([[IAU%20Directions|IAU Directions]])'' DE MORGAN.--A brilliant little crater, 4 miles in diameter, on the plain S. of the [[Ariadaeus|Ariadaeus]] cleft.<br /> <br />  
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''([[IAU%20directions|IAU Directions]])'' DE MORGAN.--A brilliant little crater, 4 miles in diameter, on the plain S. of the [[Ariadaeus|Ariadaeus]] cleft.<br /> <br />  
 
===Wikipedia===
 
===Wikipedia===
 
[http://en.wikipedia.org/wiki/De_Morgan_(crater) De Morgan]<br /> <br />  
 
[http://en.wikipedia.org/wiki/De_Morgan_(crater) De Morgan]<br /> <br />  
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* IAU page: [http://planetarynames.wr.usgs.gov/Feature/1443 De Morgan]
 
* IAU page: [http://planetarynames.wr.usgs.gov/Feature/1443 De Morgan]
* Depth data from [[Kurt%20Fisher%20crater%20depths|Kurt Fisher database]]
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* Depth data from [[Kurt%20Fisher%20Crater%20Depths|Kurt Fisher database]]
 
** Viscardy, 1985: 1.9 km
 
** Viscardy, 1985: 1.9 km
 
<br />  
 
<br />  

Latest revision as of 02:46, 16 April 2018

De Morgan

Lat: 3.3°N, Long: 14.9°E, Diam: 10 km, Depth: 1.9 km, Rükl: 34

external image de-Morgan-Clem.jpg

external image de-Morgan-closeup-clem.jpg

external image normal_demorgan-large.jpg

Left: Clementine Under high Sun, de Morgan is lost (the small unbright crater in the middle of the frame) amid the dark rays of Dionysius and the crisp bright walled Cayley, immediately above de Morgan. Middle: Clementine closeup Right: Lunar Orbiter LO-4090-H1 image from the Lunar & Planetary Institute.

Images

LPOD Photo Gallery Lunar Orbiter Images Apollo Images

  • Although there's nothing in the LPI's search list for orbital Apollo photographs of De Morgan and nearby craters Cayley, D'Arrest, and Whewell, these craters were captured on several frames of Apollo 16's north-looking metric/mapping Fairchild camera, such as frame AS16-M-0831. In this frame, De Morgan and its surrounding craters are visible near the central part of the curved horizon.
  • Research: Danny Caes.



Maps

(LAC zone 60D4) LAC map Geologic map LM map AIC map

Description

Clementine provides an excellent view of this standard little simple crater. It has steep walls and a flat floor with two tiny hills as central peaks. de Morgan's walls are not nearly as bright as those of nearby Cayley, suggesting that the smaller crater is older. This is supported by noting that Cayley truncates one of the dark rays from Dionysius, whereas a piece of the dark ejecta seems to impinge on the western wall of de Morgan. But two other dark areas occur along the northern wall so perhaps this is just a buried pyroclastic layer - the same one that is the source of Dionysius' rays. - tychocrater Sep 26, 2007

Elger

(IAU Directions) DE MORGAN.--A brilliant little crater, 4 miles in diameter, on the plain S. of the Ariadaeus cleft.

Wikipedia

De Morgan

Additional Information


Nomenclature

  • Named for Augustus de Morgan (June 27, 1806 – March 18, 1871), an Indian-born British mathematician and logician. He formulated De Morgan's laws and was the first to introduce the term, and make rigorous the idea of mathematical induction.


LPOD Articles

How Deep is that Hole?

Bibliography

Harold Hill. A Portfolio of Lunar Drawings, page 5 (the Ariadaeus rille).

Augustus de Morgan in the Sourcebook Project (William R. Corliss)

- Page 127 in Mysterious Universe, a handbook of astronomical anomalies (1979) :
  • The Maedler Phenomenon (Richard Baum, Strolling Astronomer, 1978).



Named Features -- Prev: De Moraes -- Next: De Roy