Hitchhiker's Guide to Rukl Chart 19

Harbinger Mountains (JRF <freeman _at_ netcom.com>)

These isolated mountains near the southern edge of Mare Imbrium are so-called because their appearance at lunar dawn just precedes the entry of Aristarchus (Rukl chart 18) into sunlight.

Prinz (JRF <freeman _at_ netcom.com>)

Half-flooded remains of a crater, with a small system of rilles to the north.

Krieger (Matt Tarlach <tarlach _at_ earthlink.net>)

One of the more interesting sights was provided by the crater Krieger. The small crater Van Biesbroeck, which sits astride Krieger's rim, was unevenly illuminated, with the intersections of the superimposed rims shining brightly and the rest of Van Biesbroeck barely visible. At first glance it really looked more like a cleft in Kreiger, guarded by high mountains.

T. Meyer (...Akkana)

Like Encke, T. Meyer looks hexagonal to me; the two craters, fairly near each other, look quite similar. However, Rukl shows no sign of this in his drawing of T. Meyer, whereas his drawing of Encke clearly shows the hexagonal shape.

Rima Brayley (Rich Neuschaefer <rich.neuschaefer _at_ TANDEM.com>)

On chart #19 of Rukl's Atlas of the Moon there is an interesting looking long (240 km) narrow rille called Rima Brayley. The atlas says "..not observable with small telescopes." After reading the Observation of the Moon chapter in the Rukl's atlas (page 208) he may be calling "small" a telescope under six inches but it is still not clear to me what sized telescope is required to see Rima Brayley.

Have you seen Rima Brayley? What size and type of telescope were you using? How small a telescope do you think could see (resolve) Rima Brayley?

July 4, 1998: What I saw looked like a very thin dark line, not really straight, but not the same meanders shown in Rukl's atlas.

The next night, Sunday, July 7th shortly after the sky got reasonably dark I caught glimpses of what I think was Rima Brayley near Brayley. It was a thin bright line that had similar meanders and a little more of the the rima a little farther north. The views were brief and I hope I wasn't accidentally playing connect the dots very small bright spots. It is one of those things that seemed very real briefly but as the night and the terminator moved on I couldn't see the Rima Brayley meander so it makes me want to question my observation.

The rima near "the rock", an elongated pile of rocks at about 35 deg w. and 21 deg n. This short rima runs next to "the rock" and on the opposite side of crater Brayley as rima Brayley. This rima was a very thin bright meander. I saw it enough times Sunday evening that I feel good about this observation.

Rima Brayley (JRF <freeman _at_ netcom.com>)

July 4, 1998 with a 5-inch Meade 127 ED refractor: The position of the terminator was well-placed for viewing a "challenge" lunar object, Rima Brayley, which lies at about 21 N, 37 W, in selenographic coordinates. This narrow rille is plotted on the large version of Rukl's _Atlas_of_the_Moon_, the one published by Kalmbach, but not on the smaller Rukl atlas from Hamlyn.

In brief intervals of excellent seeing, I could distinguish the part of the rille immediately due north of Brayley, at 285x (4 mm Vixen Lanthanum LV eyepiece). The rille appeared as a very fine dark line. The sunrise terminator was 30 or 40 Km west of Brayley at the time of the observation.

When the seeing steadied, I saw a short, slightly curving line segment, less than one Brayley-diameter in length, located a bit north of Brayley, positioned and oriented as is Rima Brayley on the Rukl charts. I saw it only two or three times, for a few seconds at a time, in perhaps fifteen minutes of looking through my Meade at that specific area. During a much briefer glance through Rich's AP, I saw the same thing once or twice. The line was narrow and dark, showing no perceptible width, and no variation in intensity along the section that I could see. It was faint and insignificant enough that I probably would not have noticed it if I had not known exactly where to look.

Using my 5-inch, I looked for Rima Brayley at several other places along its length, by reference to some of the hummocks and ridges that it passes, but could find no trace of it anywhere else.

The wrinkle ridge system that is tangent to Brayley on the (selenographic) SW side, that trends SE/NW, was prominent, as was much other detail in the area.

I also looked for a rille plotted but not named by Rukl, that lies at about 21 N, 35 W. I could not see it, although a white albedo feature near that location was prominent. The feature lies a few Km SE of an unnamed peak at about 21.3 N, 35.5 W, and as near as Rukl's atlas allows me to judge, is superimposed on the unnamed rille at that location.

Rima Brayley (<tracy2 _at_ mindspring.com> Tracy Wilson)

For only 1 or 2 minutes the hooked part was plainly visible in my 8" F5.5 Dob on Poncet (240X) Sunday night. The other half was invisable to me. This took about 30 to 45 minutes before seeing would allow me my first and only look. I suspect on a better night and a day sooner would be *much* better and that a smaller scope could bag it.

Natasha (Matt Tarlach <tarlach _at_ earthlink.net>)

In southern Imbrium a busy area southwest of Euler attracted attention. The only crater evident here (with 90mm) is Natasha, a neat, bright ring that appeared to have a flooded floor. Scattered about were many bright lumps, standing out clearly from the Mare and throwing noticeable shadows - it looked like a field of boulders. Rukl shows a field of domes in this area, but near the terminator the features appeared much more distinct and upright than the classic domes to the south. Interestingly, the lunar map of H.P. Wilkins (plotted with the aid of some quite large instruments) depicts this area as filled with ruined rings and small, walled craterlets. Quite different from Rukl's view, and different again from the appearance in small aperture.