De Morgan

From The Moon
Jump to: navigation, search

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.


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.


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


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


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


De Morgan

Additional Information


  • 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?


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