Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Sunday, January 2, 2022

lunar lines: Rima Ariadaeus

a long straight trough on the moon is called a rille (german for groove). just to confuse, "rima" the latin term for crack or fissure  is used when naming these objects.  

Rima Ariadaeus is thought to have been formed when a section of the Moon's crust sank down between two parallel fault lines (click image for wider view):

Rima Ariadaeus
9/13/2021 03:02 UTC

Objects on the terminator (day/night line on the moon) are contrast enhanced by shadows from low angled light--a bit too much in this image as the bottom portion of the line is lost in shadow.  


next up is the crater posodinius:
Posodinius
9/13/2021 02:59 UTC

the secondary rim (top) is apparently not another crater, rather the floor of the crater is fractured and tilted, creating a 1 km drop. also, you'll notice a faint rille crossing from center to upper right.  the crater was not near the terminator during this capture, so the contrast is poor. might revisit while closer to the terminator to capture the rille.


references:
https://en.wikipedia.org/wiki/Rima_Ariadaeu03
http://lroc.sese.asu.edu/posts/796

Image details:
camera ZWO ASI 290MM 
filters: ZWO IR pass 850 
(seeing was mediocre with the 850 filter clearly sharper than a Baader IR pass "685")
celestron 11" Edge HD, no barlow
East Bluff, CA
9/13/21 02:59-03:02 UTC
moon waxing crescent 6.6 day old
FPS (avg.)=73
Shutter=12ms
Gain=251 (41%)