Hitchhiker's Guide to Rukl Chart 72

See also Robin Casady's labelled image of Clavius for a chart of the smaller craters in and around Clavius.

Clavius (JRF <freeman _at_ netcom.com>)

Clavius is a "landmark" feature, easily recognized and useful for orientation. Overlapping craters Porter and Rutherford make it particularly simple to identify. Clavius D, C, N, and J form a prominent arc on its floor, and there are a wealth of smaller craterlets there, too.

Clavius at sunrise (...Akkana)

Sunrise over Clavius is beautiful. I caught and sketched the sequence at right at a public star party; the sketch at left, two months later from my driveway.

Clavius at sunrise (Robin Casady)

This CCD image of the sunrise over Clavius was taken the same night as the two sketches above right.

Clavius (Philip Sacco <ppsacco _at_ mindspring.com>)

5/4/96: The crater Clavius was a wonder to view around, as the terminator was cutting thru the middle of it by the time I got to it.....The Western rim of the crater was in bright sunrise, while the crater floor east of the rim was stillin shadow. Craters C and D were well illuminated as was the area in the immediate vacinity, whil the areas to the West and East of clavius' floor were still in shadow. This optically allowed one to see the amount of rise the middle area of Clavius' floor displays unlike other times of illumination when the entire floor apears evenly lit....

There was a very brightly lit extension running south of Porter pointing towards crater C. The extension doesn't appear in the Rukl Atlas, however it must be a slight rise on the southern rim of Porter jutting southward.

In measuring the diameter of Clavius I found the Eastern rim to entail some 36-42 km of inclined wall from the surrounding terrain to the inner edge of the rim. The elevation of the Eastern rim cast a wide shadow across the floor of Clavius towards C and D. This central area was fully illuminated as I noted previously, and it gave a very interesting indication of the contours and slight elevation of Clavius' central floor area around D/C complex.

Longomontanus Sunrise Ray (Jim Ferreira)

The crater ray that Donald [Donald Qualls, aka The Silent Observer] has described [editor's note: in an April 27, 1999 posting on the shallow-sky list, and followup discussion pinned down what crater it was -- see the archives for the thread] was very likely in the crater Longomontanus. I was video imaging the moon Saturday night / Sunday morning and captured an image of Longomontanus showing a v-shape, ray-like light crossing the smooth crater floor. There is a small group of peaks near the center of Longomontanus and they did indeed cast a shadow across the floor almost to the western wall of the crater. I have never seen the Walter's ray, but I have little doubt that it would be similar in appearance to the light on the floor of Longomontanus.

Scheiner (David North <d _at_ timocharis.com>)

Scheiner has a series of craters in an "L" shape, similar in size and apparent age to the more noted arc in Clavius. There are other craters of this type all over the area; I don't know if this implies an "event" or if they are just coincidental, but it's pointed to note such a similar feature so nearby.

South Pole region (Steve Coe <scoeandlross _at_ sprintmail.com>)

Blancanus--this crater has a smooth floor except on the south side, where there are 12 little craterlets that mark up the floor of this sizeable crater. There is a tiny central peak and some terracing in the walls.

Scheiner--is a medium size crater with a central craterlet rather than a peak. There are two other craters of equal size on the north side of the crater floor. A rille cuts this crater into 1/3 and 2/3 pieces in a E-W path. Several small craters are on the walls, which are somewhat terraced.

Klaproth--has a very smooth floor within this large crater. The south wall is overlapped by crater Casatus. There is a small amount of terracing in the walls, but not much. Originally I did not see any craterlets on the floor of this crater, but in a moment of good seeing, two tiny craterlets appeared for a moment on the north side of the floor.

Casatus--is about the same size as Klaproth, its north wall is the south wall of Klaproth. The are two obvious medium sized craters within this larger one, one of the craters is on the south side of the floor and one is in the center of Casatus.