P63 in the visible (left) and infrared (M band, right), similar to Figure 2 but with a different color scale to improve readability. We now overimpose the colored boxes introduced in the text. On the left, the red dashed curve shows a typical reconstruction of the patera size from the visible image, used to estimate the area when USGS data are unavailable. On the right, three boxes of different sizes are used for the crust radiance estimation algorithm: The large white box encloses the entire patera and is used to estimate the total M-band radiance. The medium green box encloses most of the crust but may include a small contribution from the ring. The small red box contains only crust. See the main text for details.