(a) The heliocentric distance and the surface temperature as functions of the true anomaly of 311P at the start time of emission (see Table 3). The emission activities are indicated by red pentagons. Heliocentric distance and surface temperature of 311P when it passed through perihelion q (blue solid line) and aphelion Q (blue dashed line) are shown. (b) Dimensionless strengths of the tidal effects caused by Mars (red pentagon) and Jupiter (blue pentagon) at the surface of 311P as functions of the true anomaly of 311P at the start time of emission. Here, the dimensionless strength of the tidal effect is the ratio of the tidal force caused by the planet relative to the internal gravity of 311P at the surface of 311P (Equation (9)).