Does anyone know how I could convert data from Planck, which appear as an oval shape, into a form that I can easily map onto a sphere (ie. a rectangular shape in 2:1 aspect ratio)? Here is an example Planck image: http://sci.esa.int/science-e-media/img/61/Planck_CMB_Mollweide_4k.jpg I see that NASA have something called 'Science on a Sphere' where they have taken similar data (ie. WMAP) and managed to project it onto a sphere (see here), so it must be possible! Does anyone know the process for this? Thanks!