  It has been shown that temperature cycles on airless bodies of our Solar
System can cause damaging of surface materials. Nevertheless, propagation
mechanisms in the case of space objects are still poorly understood. Present
work combines a thermoelasticity model together with linear elastic fracture
mechanics theory to predict fracture propagation in the presence of thermal
gradients generated by diurnal temperature cycling and under conditions similar
to those existing on the asteroid Bennu. The crack direction is computed using
the maximal strain energy release rate criterion, which is implemented using
finite elements and the so-called G$\theta$ method (Uribe-Su\'arez et al. 2020.
Eng. Fracture Mech. 227:106918). Using the implemented methodology, crack
propagation direction for an initial crack tip in different positions and for
different orientations is computed. It is found that cracks preferentially
propagate in the North to South (N-S), in the North-East to South-West (NE-SW)
and in the North-West to South-East (NW-SE) directions. Finally, thermal
fatigue analysis was performed in order to estimate the crack growth rate.
Computed value is in good agreement with available experimental evidence.
