On my icon <---here you can see Blog Entries. Click on the "8" and have a look through that blog and it talks about Photogrammetry. What you need is to build a 3D model which is textured using some app which can take in a lot of images and stitch them into a 3D ball. The best 3D stitching program I know of is Meshroom. On my blog I detail about how to use Meshroom to create that marble sculpture and its just the same only your item is rounder.

Once you have the 3D object, get it into Blender as a textured item and then look up how to export the texture unwrapped. You will want to use the Cylindrical unwrapping to get the texture as a Mercator style projection.