More on the Moon

Continuing image processing from the 7^th, the following image is from further “up” the terminator.

Rima Sirsalis

This is an annotated image from near the crater Sirsalis. However, the large dark-ish area on the right side is Mare Humorum (Sea of Moisture), with the crater Cassendi in about the 11 o'clock position on the rim of the Mare. But the star of the image is what is both circled and pointed to, Rimae Sirsalis. Rimae Sirsalis is, both apparently and in several references, the longest rille on the moon, about 460 km or about 265 miles. So, what's up with rima and rilles? “Rima” is the Latin term for rille. A rille is a fissure or long, narrow channel on the moon. Another interesting point I found while looking this up (while in “social isolation” for the COVID-19 virus pandemic); sources give different lengths for the rille (Virtual Moon gives it at 182 miles, WiKipedia is the source for 426 km). It would seem there is a problem that really shouldn't be a problem. My own estimation is around 217 miles, but I'm looking at it from an angle and at relatively low resolution. I suppose my guess is no better than the other 2, and perhaps no worse!