If left on Mars, what primarily determines the long-term structural failure of a body, ignoring biological action?

Answer

Physical stresses such as micrometeorite impacts or dust abrasion.

Since chemical and biological breakdown are arrested, the dominant degradation factors over geological timescales will be physical forces like abrasion or the constant mechanical stress from extreme thermal cycling.

If left on Mars, what primarily determines the long-term structural failure of a body, ignoring biological action?
MarsSpacedecompositionbodyastrobiology