You can’t have interplanetary mining with a block time of 10 minutes. The choice of ten minutes centralizes mining to within just a a light minute or two of the majority of hash power. As no planet is that close, 100% of mined blocks occur close to earth…until extraterrestrial hash power overtakes earth’s and completely replaces it, if such extraterrestrial hash power can be accumulated. But at 51%, earth gets 100% of the blocks.