The jump from "we can compute this" to "we computed it for the entire planet" is what makes this impressive. A lot of projects stop at the proof of concept. Running hundreds of AMD Turin cores for two days straight to actually finish the job is a different kind of commitment. Curious about the edge cases, how do you handle atmospheric refraction at those distances? At 530km the curvature of the earth and atmospheric bending would meaningfully affect whether a line of sight is actually visible to a human observer versus just geometrically unobstructed.