Davy Crater Chain
Davy Crater Chain
(informal name; IAU name: Catena Davy, formerly Rima Davy I)
Lat: 10.98°S, Long: 6.27°W, Length: 52.34 km, Rukl: 43
- Ranger 9 made several photographs of Catena Davy, such as Frame A031 (which shows the chain near the frame's upper margin).
- Several orbital Hasselblad photographs of Catena Davy are online in the LPI's list of Davy Y, such as the list's first 9 frames made by Apollo 12 and Apollo 14.
- AS12-51-7485 is probably the most impressive orbital Hasselblad photograph of Catena Davy.
- Luna 22 made a rather curious photograph of Catena Davy (located near the centre of this panoramic strip) and its environs.
- Research Ranger 9, Apollo 12, Apollo 14, and Luna 22 photographs: Danny Caes
- IAU page: Catena Davy
- Several of the small craters of which this chain is composed were given informal names during the preparation of Topophotomap 77D1S1(10). Since the names on those maps were adopted by the IAU in 1976, they have entered the IAU Nomenclature as Minor Features.
- Near the middle of the crater chain (at 11.049 S/6.374 W in the coordinate system of LTO 77D1) there is a fairly prominent crater 2.6 km in diameter and about 400 m deep (according to the contours on LTO 77D1). It is labeled Davy YA on the Geologic Map. This crater has no IAU name. The ones that are named are the six craters to the immediate east of this: Susan, Osman, Priscilla, Alan, Delia and Harold, with Harold -- 200 m deep -- touching the inner east wall of Davy Y (the lettered crater on whose floor most of the chain lies) -- and Susan -- just 70 m deep according to the LTO -- being virtually undetectable on Earth-based photos or on the Clementine image shown here. The fact that Susan..Harold (as opposed to the more prominent craters in the chain) received names is a completely arbitrary twist of fate having to do with the exact area that happened to be mapped in Topophotomap 77D1/S1 and the whimsy of the cartographer. They have no special significance. Why these sub-feature names were not assigned in a more logical sequence (such as alphabetically), and why these and the many of the other Minor Feature names appearing on the Topophotomaps came to be recognized by the IAU (when the map-makers appear to have asked that they not be) is lost in the mists of time.
- Aside from Susan..Harold, the only other crater in the chain to have an official IAU name is the large one at the west end: Davy C, with a diameter of about 3.3 km and a depth of about 300 m. On the Geologic Map, the similarly sized crater at the east end is called Davy YD. It is just outside the rim of Davy Y and may or may not be part of the chain, geologically. In any event, Davy YD is no longer an official name, nor is Davy YA.
- It might also be noted that Topophotomap 77D1/S1 is oddly titled "Davy Catena" and on it, the chain is labeled that way. The word "Catena" is intended as a prefix in the IAU system and the name is written "Catena Davy" on all other maps where it appears. The chain does not seem to have had a name in Blagg and Müller or the System of Lunar Craters.
- Additional trivia: LAC-77 and Geologic Map I-566 (which uses LAC-77 for its background) shows 5 equally spaced craters, link peas in a pod, between "Davy YA" and the wall of Davy Y. The chain is depicted much more accurately on LM-77, based on Lunar Orbiter and Apollo photos. There are actually 4 peas-in-a-pod craters in this interval (Osman, Priscilla, Alan, Delia) with Harold similarly-sized, but detached to the west; and two or three non-descript craters in the space between Davy YA and Osman -- Susan is the easternmost of these. The number of small craters between Davy YA and the wall of Davy Y is not 5, but more like 7 or 8.
- Based on the shadows in LO-IV-108H and LO-IV-113H, the depth of Davy YA (the prominent crater in the middle of the chain) is about 520 m. Davy C (the 3 km diameter crater at the west end) is about 550 m deep. The pea-pod craters average about 300 m in depth. Delia is a bit deeper than that; while Priscilla and Harold are shallower. Susan and the similar unnamed crater between her and Davy YA are too shallow to cast full shadows at the sun angle of these photos. There is an additional pit about 1 km in diameter and 150 m deep touching the east rim of Davy YA. - JimMosher
- List of Lunar Catenae.
- Named from nearby crater. (Davy)
- This feature was labeled Davy I in the System of Lunar Craters and presumably, due to the latinization of such names in 1961, was intended to be read as Rima Davy.
- The name Catena Davy was provisionally introduced on LTO-77D1 (for which it served as the chart title). It was also provisionally called Davy Catena on Topophotomap 77D1(S1), in which form it served as the chart title. - JimMosher
L51: Result of comet-fragment impacts.
- Wood, C.A. Nov. 2002. Imbrium Lineaments and Davy's Weird Chain. S&T Nov 2002 v104 p112.
- Drawing and text by Alika Herring. S&T April 1959, p. 334.
- Apollo Over the Moon, Chapter 5: Craters (Part 3), Figures 130 and 131.