Difference between revisions of "Geminus"

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[http://www.lpod.org/coppermine/displayimage.php?pid=563&fullsize=1 [[Image:normal_geminus_2006.05.02.jpg|external image normal_geminus_2006.05.02.jpg]]]<br /> ''[http://lpod.org/coppermine/displayimage.php?pos=-563 Oliver Pettenpaul]'' '''Geminus''' is the crater just to the left of center in this view with north to the left. Behind it, to its upper right (east) is the 47 km [http://the-moon.us/wiki/Bernoulli Bernoulli], and to Geminus' lower right (south) is 56 km [http://the-moon.us/wiki/Burckhardt Burckhardt]. A small piece of the large crater [http://the-moon.us/wiki/Cleomedes Cleomedes] is just visible in the extreme lower right (with [http://the-moon.us/wiki/Debes Debes] and [http://the-moon.us/wiki/Tralles Tralles] on the lower right margin), and of [http://the-moon.us/wiki/Messala Messala] in the upper left. The IAU's '''Geminus A''' is the undistinguished little 15 km crater at bottom, on the centerline; with the slightly larger and more irregular '''Geminus F''' to its left.<br /> <br />  
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[http://www.lpod.org/coppermine/displayimage.php?pid=563&fullsize=1 [[Image:Normal_geminus_2006.05.02.jpg|external image normal_geminus_2006.05.02.jpg]]]<br /> ''[http://lpod.org/coppermine/displayimage.php?pos=-563 Oliver Pettenpaul]'' '''Geminus''' is the crater just to the left of center in this view with north to the left. Behind it, to its upper right (east) is the 47 km [http://the-moon.us/wiki/Bernoulli Bernoulli], and to Geminus' lower right (south) is 56 km [http://the-moon.us/wiki/Burckhardt Burckhardt]. A small piece of the large crater [http://the-moon.us/wiki/Cleomedes Cleomedes] is just visible in the extreme lower right (with [http://the-moon.us/wiki/Debes Debes] and [http://the-moon.us/wiki/Tralles Tralles] on the lower right margin), and of [http://the-moon.us/wiki/Messala Messala] in the upper left. The IAU's '''Geminus A''' is the undistinguished little 15 km crater at bottom, on the centerline; with the slightly larger and more irregular '''Geminus F''' to its left.<br /> <br />  
 
==Images==
 
==Images==
 
[http://www.lpod.org/coppermine/thumbnails.php?album=search&type=full&search=Geminus LPOD Photo Gallery] [http://www.lpi.usra.edu/resources/lunar_orbiter/bin/srch_nam.shtml?Geminus%7C0 Lunar Orbiter Images] [http://www.lpi.usra.edu/resources/apollo/search/feature/?feature=Geminus Apollo Images]<br /> <br />  
 
[http://www.lpod.org/coppermine/thumbnails.php?album=search&type=full&search=Geminus LPOD Photo Gallery] [http://www.lpi.usra.edu/resources/lunar_orbiter/bin/srch_nam.shtml?Geminus%7C0 Lunar Orbiter Images] [http://www.lpi.usra.edu/resources/apollo/search/feature/?feature=Geminus Apollo Images]<br /> <br />  
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<br />  
 
<br />  
 
==Description: Elger==
 
==Description: Elger==
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''([http://the-moon.us/wiki/IAU%20Directions IAU Directions])'' GEMINUS.--A fine regular ring-plain, 54 miles in diameter, nearly circular, with bright walls, rising on the W. to a height of more than 12,000 feet, and on the opposite side to nearly 16,000 feet above the floor. Their crest is everywhere very steep, and the inner slope is much terraced. There is a small but conspicuous mountain in the interior; N. of which I have seen a long ridge, where Schmidt shows some hillocks. Two fine clefts are easily visible within the ring, one running for some distance on the S.W. side of the floor, mounting the inner slope of the S.E. border to the summit ridge (where it is apparently interrupted), and then striking across the plain in a S.E. direction. Here it is accompanied for a short distance by a somewhat coarser companion, running parallel to it on the N. The other cleft occupies a very similar position on the N.E. side of the floor at the inner foot of the wall. On several occasions, when observing this formation and the vicinity, I have been struck by its peculiar colour under a low evening sun. At this time the whole region appears to be of a warm light brown or sepia tone.<br /> <br />  
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''([http://the-moon.us/wiki/IAU%20directions IAU Directions])'' GEMINUS.--A fine regular ring-plain, 54 miles in diameter, nearly circular, with bright walls, rising on the W. to a height of more than 12,000 feet, and on the opposite side to nearly 16,000 feet above the floor. Their crest is everywhere very steep, and the inner slope is much terraced. There is a small but conspicuous mountain in the interior; N. of which I have seen a long ridge, where Schmidt shows some hillocks. Two fine clefts are easily visible within the ring, one running for some distance on the S.W. side of the floor, mounting the inner slope of the S.E. border to the summit ridge (where it is apparently interrupted), and then striking across the plain in a S.E. direction. Here it is accompanied for a short distance by a somewhat coarser companion, running parallel to it on the N. The other cleft occupies a very similar position on the N.E. side of the floor at the inner foot of the wall. On several occasions, when observing this formation and the vicinity, I have been struck by its peculiar colour under a low evening sun. At this time the whole region appears to be of a warm light brown or sepia tone.<br /> <br />  
 
==Sepia==
 
==Sepia==
 
  The last bit of Elger's description of '''Geminus''' is a very interesting one (the peculiar warm light brownish or sepia-ish coloration), because this seems to be a frequent phenomenon whenever certain regions near the moon's eastern limb are observed during Waning Gibbous Moon, when the evening terminator runs along these regions.<span class="membersnap">- DannyCaes <small>Nov 2, 2012</small></span><br />  See also Walter Goodacre's observation of a brownish coloration at '''Atlas''' during local evening light.<span class="membersnap">- DannyCaes <small>Nov 2, 2012</small></span><br />  Is there an equivalent of the same kind of phenomenon at western limb regions during Waxing Gibbous Moon? (near Full Moon); for example Harold Hill's observation of a reddish coloration near '''Lichtenberg''', and Richard Baum's observation of the same sort of reddish coloration near '''Philolaus'''. Each one of those observations happened about two days before Full Moon.<span class="membersnap">- DannyCaes <small>Jul 27, 2013</small></span><br /> <br />  
 
  The last bit of Elger's description of '''Geminus''' is a very interesting one (the peculiar warm light brownish or sepia-ish coloration), because this seems to be a frequent phenomenon whenever certain regions near the moon's eastern limb are observed during Waning Gibbous Moon, when the evening terminator runs along these regions.<span class="membersnap">- DannyCaes <small>Nov 2, 2012</small></span><br />  See also Walter Goodacre's observation of a brownish coloration at '''Atlas''' during local evening light.<span class="membersnap">- DannyCaes <small>Nov 2, 2012</small></span><br />  Is there an equivalent of the same kind of phenomenon at western limb regions during Waxing Gibbous Moon? (near Full Moon); for example Harold Hill's observation of a reddish coloration near '''Lichtenberg''', and Richard Baum's observation of the same sort of reddish coloration near '''Philolaus'''. Each one of those observations happened about two days before Full Moon.<span class="membersnap">- DannyCaes <small>Jul 27, 2013</small></span><br /> <br />  
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[http://en.wikipedia.org/wiki/Geminus_(crater) Geminus]<br /> <br />  
 
[http://en.wikipedia.org/wiki/Geminus_(crater) Geminus]<br /> <br />  
 
==Additional Information==
 
==Additional Information==
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* Depth data from [http://the-moon.us/wiki/Kurt%20Fisher%20crater%20depths Kurt Fisher database]<br />  Westfall, 2000: 4.76 km<br />  Viscardy, 1985: 5.4 km<br />  Cherrington, 1969: 2.86 km
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* Depth data from [http://the-moon.us/wiki/Kurt%20Fisher%20Crater%20Depths Kurt Fisher database]<br />  Westfall, 2000: 4.76 km<br />  Viscardy, 1985: 5.4 km<br />  Cherrington, 1969: 2.86 km
 
* TSI = 35, CPI = 25, FI = 25; MI =85 [http://the-moon.us/wiki/Smith%20and%20Sanchez%2C%201973 Smith and Sanchez, 1973]
 
* TSI = 35, CPI = 25, FI = 25; MI =85 [http://the-moon.us/wiki/Smith%20and%20Sanchez%2C%201973 Smith and Sanchez, 1973]
 
* '''Central Peak Height''': Main peak = 1.1 km (1085 m approx., -- [http://the-moon.us/wiki/file/detail/Geminus-Peaks.jpg calculated] from shadows in [http://www.lpi.usra.edu/resources/lunarorbiter/frame/?4191 LO Frame 4191 H2] using [http://ltvt.wikispaces.com/LTVT LTVT]) <span class="membersnap">- [http://www.wikispaces.com/user/view/JohnMoore2 [[Image:JohnMoore2-lg.jpg|16px|JohnMoore2]]] [http://www.wikispaces.com/user/view/JohnMoore2 JohnMoore2]</span> . By the [http://target.lroc.asu.edu/da/qmap.html LRO ]altimetry tool, the height is 900 m <span class="membersnap">- [http://www.wikispaces.com/user/view/Nunki [[Image:Nunki-lg.jpg|16px|Nunki]]] [http://www.wikispaces.com/user/view/Nunki Nunki]</span>
 
* '''Central Peak Height''': Main peak = 1.1 km (1085 m approx., -- [http://the-moon.us/wiki/file/detail/Geminus-Peaks.jpg calculated] from shadows in [http://www.lpi.usra.edu/resources/lunarorbiter/frame/?4191 LO Frame 4191 H2] using [http://ltvt.wikispaces.com/LTVT LTVT]) <span class="membersnap">- [http://www.wikispaces.com/user/view/JohnMoore2 [[Image:JohnMoore2-lg.jpg|16px|JohnMoore2]]] [http://www.wikispaces.com/user/view/JohnMoore2 JohnMoore2]</span> . By the [http://target.lroc.asu.edu/da/qmap.html LRO ]altimetry tool, the height is 900 m <span class="membersnap">- [http://www.wikispaces.com/user/view/Nunki [[Image:Nunki-lg.jpg|16px|Nunki]]] [http://www.wikispaces.com/user/view/Nunki Nunki]</span>

Revision as of 01:50, 16 April 2018

Geminus

Lat: 34.5°N, Long: 56.7°E, Diam: 85 km, Depth: 4.76 km, Rükl: 16

external image normal_geminus_2006.05.02.jpg
Oliver Pettenpaul Geminus is the crater just to the left of center in this view with north to the left. Behind it, to its upper right (east) is the 47 km Bernoulli, and to Geminus' lower right (south) is 56 km Burckhardt. A small piece of the large crater Cleomedes is just visible in the extreme lower right (with Debes and Tralles on the lower right margin), and of Messala in the upper left. The IAU's Geminus A is the undistinguished little 15 km crater at bottom, on the centerline; with the slightly larger and more irregular Geminus F to its left.

Images

LPOD Photo Gallery Lunar Orbiter Images Apollo Images

Maps

(LAC zone 27C3) LAC map Geologic map

Description


Description: Elger

(IAU Directions) GEMINUS.--A fine regular ring-plain, 54 miles in diameter, nearly circular, with bright walls, rising on the W. to a height of more than 12,000 feet, and on the opposite side to nearly 16,000 feet above the floor. Their crest is everywhere very steep, and the inner slope is much terraced. There is a small but conspicuous mountain in the interior; N. of which I have seen a long ridge, where Schmidt shows some hillocks. Two fine clefts are easily visible within the ring, one running for some distance on the S.W. side of the floor, mounting the inner slope of the S.E. border to the summit ridge (where it is apparently interrupted), and then striking across the plain in a S.E. direction. Here it is accompanied for a short distance by a somewhat coarser companion, running parallel to it on the N. The other cleft occupies a very similar position on the N.E. side of the floor at the inner foot of the wall. On several occasions, when observing this formation and the vicinity, I have been struck by its peculiar colour under a low evening sun. At this time the whole region appears to be of a warm light brown or sepia tone.

Sepia

The last bit of Elger's description of Geminus is a very interesting one (the peculiar warm light brownish or sepia-ish coloration), because this seems to be a frequent phenomenon whenever certain regions near the moon's eastern limb are observed during Waning Gibbous Moon, when the evening terminator runs along these regions.- DannyCaes Nov 2, 2012
  See also Walter Goodacre's observation of a brownish coloration at Atlas during local evening light.- DannyCaes Nov 2, 2012
  Is there an equivalent of the same kind of phenomenon at western limb regions during Waxing Gibbous Moon? (near Full Moon); for example Harold Hill's observation of a reddish coloration near Lichtenberg, and Richard Baum's observation of the same sort of reddish coloration near Philolaus. Each one of those observations happened about two days before Full Moon.- DannyCaes Jul 27, 2013

Description: Wikipedia

Geminus

Additional Information



Nomenclature

  • Named for Geminus of Rhodes (ca.110 - 40 BCE), a Greek astronomer and mathematician. During his career he wrote introductory works in mathematics and astronomy, and is typically credited with the construction of the Antikythera mechanism. His astronomical observations noted that the length of a day varied in different parts of the world.
  • Secondary crater Geminus A was called Athinagoras by Felix Chemla Lamech, but the I.A.U. did not accept this name. Research : Ewen A. Whitaker and Danny Caes (August 2003 mail correspondence, thanks to Jenny Blue of the USGS-IAU).
  • From the title image, the IAU's Geminus A seems a strange choice for naming. Perhaps Lamèch had a different Geminus A in mind? - Jim Mosher


Promontorium Archidaeum


LPOD Articles

A Single Twin An Older Tycho

Bibliography

Felix Chemla Lamech's Athinagoras and William Radcliffe Birt's Promontorium Archidaeum: Ewen A. Whitaker's Mapping and Naming the Moon.
  W.R. Birt (1858) On Successive Illuminations of the Lunar crater Geminus.
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