ATPM fits to the 67P/C-G a) Kelley et al. (2009) data set; and b) Lamy et al. (2008) data set. The data points are shown by the markers where their error bars represent the total absolute 1-σ uncertainty, and the model fits are shown by the lines. The triangle represents a data point that is more than a 3-σ error bar away from the best model fit. The long-dashed, solid, short-dashed, and long-dashed-dotted lines represent thermal inertia values of 0, 4, 10, and 15 J m^-2 K^-1 s^−1/2 respectively. The greyed out regions represent the 3-σ range of possible thermal-IR fluxes caused by non-uniform surface roughness for a thermal inertia of 4 J m^-2 K^-1 s^−1/2.