Orthographic view of the HEALPix partition of the sphere. The overplot of equator and meridians illustrates the octahedral symmetry of HEALPix. Light gray shading shows one of the 8 (4 north and 4 south) identical polar base‐resolution pixels. Dark gray shading shows one of the 4 identical equatorial base‐resolution pixels. Moving clockwise from the top left panel, the grid is hierarchically subdivided with the grid resolution parameter equal to ﹩N_{\mathrm{side}\,}=1﹩, 2, 4, 8, and the corresponding total number of pixels equal to ﹩N_{\mathrm{pix}\,}=12\times N^{2}_{\mathrm{side}\,}=12﹩, 48, 192, 768. All pixel centers are located on ﹩N_{\mathrm{ring}\,}=4N_{\mathrm{side}\,}-1﹩ rings of constant latitude. Within each panel the areas of all pixels are identical.