image by François Emond, Hautes-Alpes, FRANCE. North is at approximately the 1 AM position.
The Triesnecker-Hyginus area has long been subject to intense scrutiny, but probably never seen from Earth as clearly as here. François has captured this rille-filled region with low-Sun and high-res, revealing features I have never seen before. First are the layers of rilles; as known before, the Triesnecker rilles are not all of the same age. There are many narrow and faint ones, as well as a few broader, flat-floored segments that clearly are older than the deeper ones just east (below right in this view) of the crater. I have always thought that Triesnecker is younger than all the rilles, and certainly its ejecta covers rilles below and left of the crater. But are the shadow-filled, deeper rilles younger, or have they been rejuvenated since Triesnecker formed? Looking at Hyginus, François’ image shows that the eastern rille continued pass Triesnecker as a series of off-set (geologists say en echelon) troughs. Those have been filled in with some material, and the rille has since taken an abrupt turn at Hyginus toward the northwest. Finally, notice the scattered hills near the bottom center of the image. Why are they there? What formed them? They look like rubbly ejecta (from Imbrium?), but why is it exposed at just this one area? A great image leads to many new questions - this is a great image.
Note: My laptop computer’s hard drive is dead and all the submitted images for LPOD are gone, please re-submit any recent images - and more new ones, like todays! Thanks!
5 August 2007 at ~ 04 h 32 UT, in Chorges (Hautes-Alpes, FRANCE). Dobson T400 (~ 16″ Newton) + FFC Barlow lens, + webcam Vesta Pro (B & W, raw mode) + red filter with the freeware Iris. About 65 - 115 frames for each part of this photo were stacked in Iris. Final processing using Paint Shop Pro.
Yesterday's LPOD: Tycho's Projectile
Tomorrow's LPOD: The Other B&M