Thanks for the nice, succinct explanation.
PS: That also explains why the earth and the inner planets do not have significant ring structures and all the outter gas giants do. The relative strength of the perturbing forces, especially the sun, are so much stronger.
Both of Mars’ moons are believed to have been recently (like the past few million years) captured. Phobos is in retrograde orbit, opposite the direction of Mars’ rotation. The effect of tidal drag continually reduces the radius of its orbit and it is expected to collide with mars in a few million more years. (Tides actually increase the radius of our moon’s orbit by about one centimeter per year increase the length of the earth’s day by about 0.0015 seconds per century. The transfer of energy from earth’s rotation to the moon’s orbit is about one gigawatt.)