re: Martian moon
That is a nice image, Thanks.
Phobos (APOD) is thought to be a captured asteroid which have some of the same type of grooves. Impacts are the only thing I have read that explains the grooves on Phobos.
A lot of talk with Eros and the groves found there from NEAR photos but a theory of the grooves being older than the craters kind of washes the crater causing the grooves.
It just might be a formation process and thus the asteroid claim of Phobos.