Bay-shaped incomplete craters

Bay-shaped incomplete craters

(glossary entry)

Description

A bay-shaped incomplete crater is almost always located at the rim of a large basin, such as crater Fracastorius at the southern rim of the basin Mare Nectaris, or crater Le Monnier at the eastern rim of the basin Mare Serenitatis. There's also a variety of large and small bay-shaped (and arc-shaped) craters (and remains of craters) on the floor of the large plain Oceanus Procellarum.
 
 

Handcuffs (the twisted remains of bay or arc shaped shallow craters)

• A curious field of twisted bay- and arc-shapes (the remains of small craters and crater-like depressions in the shape of open and closed handcuffs) is noticeable in the part of Mare Frigoris between J. Herschel and La Condamine, and north-northeast of La Condamine. (Rukl: 2 and Rukl: 3). The central section of photograph LO IV-152-H1 and the upper half of photograph LO IV-145-H3 show the field of the twisted bay- and arc-shapes very well. See also LAC 11 (page 22) in Ben Bussey's and Paul Spudis's Clementine Atlas of the Moon.
• Another field of bay- and arc-shapes is situated in Sinus Roris, see the lower half of LO IV-170-H3. Note also the appearance of double rim sections at those handcuffs, especially at the western section of the one located about halfway between Markov G and Louville K, see http://bit.ly/2oeCMcF.
• There are also several arcs and U-shapes west of Russell, see LO IV-183-h1.
• Note: there seems to be an abundance of Concentric Craters in the regions where those twisted bay- and arc-shapes are scattered all over, in quite large amounts.
• There's a 2 kilometer diameter handcuff east of Promontorium Heraclides, at LAT 39.77 / LON -30.11.
• About halfway between Gambart and Turner there's a curious system of two arc shaped hillocks of which the southern parts join together at a small bowl shaped crater. The coordinates of this system and the small crater are: LAT -0.50, LON -14.16 (LROC ACT-REACT Quick Map).
• At the moon's far side there's a wonderful example of a handcuff-shaped shallow crater on the western part of the floor of Jules Verne, and on the floor of Joliot.

The Two Arcs phenomenon

Perhaps the best example of this phenomenon (two arcs of an incomplete crater, arranged at locations opposite of each other) is Eddington P on the floor of Eddington, see:
 http://bit.ly/1znZ8IL
  Another example is (or are) the two arcs at Rimae Hippalus, see:
 http://bit.ly/1s2ya1F
  There's a third example east of Gassendi, see:
 http://bit.ly/1znZXkL
 
 
 

A list of typical bay-shaped incomplete craters (and arc-shaped remains of craters) on the moon's near side.

- Lenard at the farside rim of Hermite (Rukl: 4).
  - Meton C + Meton D (Rukl: 5).
  - Danjon (Felix C.Lamech's proposed name for the incomplete formation between Kane and Gartner)(Rukl: 5).
  - Gartner (Rukl: 6).
  - Sinus Iridum (probably the most well-known one of the moon's bay-shaped incomplete craters)(Rukl: 10).
  - Russell (Rukl: 17).
  - Prinz (Rukl: 19).
  - Tobias Mayer W (Rukl: 19).
  - Spurr (Rukl: 22).
  - West of Rima Yangel' (Rukl: 22), see LPOD No Longer Unremarkable.
  - Le Monnier (Rukl: 24 and Rukl: 25).
  - Maestlin R (Rukl: 29).
  - Small arc-shaped bay at 11°30' North/ 4°15' West (at the eastern "rim" of Sinus Aestuum)(Rukl: 33). See also Frame 120 of Lunar Orbiter 5 (near the left margin of 5120 med).
  - The Seagull at 13°30' North/ 19°50' East (a curious system of two arc-shaped crater remains)(Rukl: 35).
  - Aryabhata (Maskelyne E), and Maskelyne F south of it (Rukl: 36).
  - Damoiseau H (Rukl: 39).
  - Sirsalis E (Rukl: 39 and Rukl: 40).
  - Letronne (Rukl: 40).
  - Flamsteed G (Rukl: 40).
  - Leon Hills (an unofficial name for Wichmann R)(Rukl: 41).
  - Unnamed arc at 9° South/ 36° West (east-northeast of craterlet Scheele)(Rukl: 41).
  - Herigonius Upsilon at 11°15' South/ 33°20' West (north-northeast of crater Herigonius)(Rukl: 41). LPOD Features of interest in a small area.
  - Montes Riphaeus at Mare Cognitum (Rukl: 41 and Rukl: 42).
  - Horseshoe (Harold Hill's nickname for Parry M)(Rukl: 43).
  - Unnamed arc at 8°50' South/ 11°35' West (north of Kundt in the northern part of Mare Nubium)(Rukl: 43). See also orbital Itek-photograph AS16-P-5404 (right part of frame).
  - Lade (Rukl: 45).
  - Possible remains of large crater at 1°30' South/ 24° East, of which the location of crater Moltke is almost at the large crater's "centre" (Rukl: 46).
  - Torricelli R (Rukl: 47).
  - The Rupes Recta plain or Ancient Thebit (an unofficial name for the incomplete formation surrounding Rupes Recta)(Rukl: 54).
  - Pronounced arc (Thebit alpha) at 24° South/ 7° West, in the system of hills south of Rupes Recta (once called the Stag's Horn mountains)(Rukl: 54). See LPOD Succession.
  - Pitatus S (immediately north of Pitatus)(Rukl: 54).
  - Fracastorius (Rukl: 58).
  - Balmer (Rukl: 60).
  - The curious arc-shaped remains of a small crater on the northeastern part of Abel's floor (Rukl: 69).
  - A possible "half crater" (northern part of its rim) and pronounced central peak at 0° East/ 82° South, see centre of Part M of the alphabetically arranged Southpole radar map (Rukl: 73).
 
 

LPOD Articles

Pole 2.0 (a possible "half-a-crater" with pronounced central peak at 0° East/ 82° South ?)- DannyCaes Jun 22, 2009
Succession (arc in the Stag's Horn mountains).

Bibliography

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