Hitchhiker's Guide to Rukl Chart 17

Struve

Russel

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

The Struve/Russel/Eddington complex of semighost craters is linked at the walls... emergent into daylight, they make almost as dramatic a presentation as Sinus Iridum, seeming to tail off into an infinite darkness at the far edge. A subtle run of ridges, color, and small craters add just enough imperfection to make lingering worthwhile. Near the visible edge of Oceanus Procellarum, they are clearly very large older craters that were flooded when the maria were active.

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

Krafft and Cardanus (Cardanus is on chart 28) are a remarkable pair of similar medium sized craters without any significant features in and of themselves, but between them runs the curious Catena Krafft, a chain of craters that looks at first blush like a large and easy rille. Only with the best seeing does the true nature of this feature start to emerge; I have personally never had a night when they were favorably placed that showed me clearly the craters as distinct entities -- tonight allowed a shaky 400x with profit, but even that only gave me a sort of 'sausage link' effect that was uncertain.

Nevertheless, the curious nature of this catena, running from one crater to another in a more or less straight line, is exceptional. My own speculation involves the craters having similar ages, which is the appearance, resulting in a stress area between them at formation. But I don't know.

To round out the area, Rima Cardanus just to the south is fairly easy but pretty rewarding, as it has a complex structure at the terminus away from the limb that grows more detailed with patient inspection. That the rille formed in the midst of a flattish area of mare material near the edge of Procellarum makes it a classic rille, and an excellent contrast to the more curious Catena Krafft.