...may I suggest you turning your proverbial eyes towards
our Solar System's largest asteroid: Ceres.

Since you are interested in "mud", these facts might draw your attention.

Large Asteroid Facts:

(1) The four largest and the first discovered asteroids [Ceres, Juno, Pallas, Vesta] are remarkable in that they show spectral signatures indicating diverse geosurfaces.

(2) The cores of those four large asteroids were subject to brief geological heating [by radioactivity and gravitational compression], during their
early years after formation, that caused geophysical differentiation and the creation of temporary [barely] molten cores.

(3) While such molten cores quickly cooled and solidified,
there may have been sufficient residual heat for a few thousand or millions
of years to heat deeply-buried volatiles [H20, CO2, CH4, etc], driving them through cracks, faults and fissures to the surface where they usually sputtered away into interplanetary space....but not entirely.

(4) On the surface of Ceres, however, there is a strong spectral signature
of hydrated minerals [minerals containing chemically bound water molecules, or hydroxide radicals when H20 is exposed to UV radiation].

(5) On Earth, finally ground minerals with chemically-bound water molecules,
are found in sandstone, sedimentary layers and clays.

Hypothesis:

(a) Could it be that on Ceres, early in its formative years, when its core
was still hot, 'heated' water molecules mixed with minerals and salts
oozed through cracks and fissures from the depths of Ceres to its surface
as MUD?

(b) MUD oozing onto the surface of Ceres in those early formative years would have quickly frozen, becoming as hard as rock in the intense surface cold.
But MUD could have played the same roll on Ceres that silicate LAVA
plays and played on the slopes of volcanic peaks on Earth.

Well, Bob? Have I given you enough grist for the mill?