Lunar (Th)rilles! (Mar. 2021)

This portion of the moon's surface is covered with rilles.  It looks scratched, as if a giant cat pawed across it.  But probably these features were formed when lava tubes just below the surface collapsed, or at least that is what I have read.

The crater to the right with mountains in the middle is Bullialdus.  The long scratches stretching across the center are Rimae Hippalus.  The rille across the bottom right is Rima Hesiodus.  To its left, criss-crossing a crater (Ramsden Crater), are Rimae Ramsden.  Near the top, extending from near the top of the rightmost of Rimae Hippalus is Rima Agatharchides, which travels across Crater Agatharchides P.

In the upper left are ripples, not rimae, around the edges of Mare Humorum, but they form a nice contrast to Rimae Hippalus.

This is best 1200/2000 taken with the QHY5iii485C through the CFF 290 Classical Cassegrain at its native f/13.5.