Summary of ATPM YORP effect modelling results for (1862) Apollo using its three different shape model variants (legend). a) Average YORP rotational acceleration as a function of thermal inertia. b) The distribution of possible YORP rotational acceleration values derived at the 3-σ confidence level. c) Average rate of YORP obliquity shift as a function of thermal inertia. d) The distribution of possible rates of YORP obliquity shift derived at the 3-σ confidence level. The grey lines shown in panels a) and b) represent the lower and upper bounds of the YORP rotational acceleration acting on (1862) Apollo as measured by Ďurech et al. (2008a).