High latency between miners gives an exponential advantage to miners closer to the highest concentration of compute. Unless this problem is solved, it is not possible to mine Bitcoin on multiple planets at the same time. Mining "collapses" to the single largest low-latency mining cluster.
Consider the following thought experiment.
There are exactly 2 computers in the universe, sitting 60 light minutes away from each other. Each is exactly as powerful as the other, and both are spending all of their compute mining bitcoin. Suppose they both start mining the same block at the same time ("same time" according to an observer sitting halfway between them). After about 10 minutes, one of them (call it computer A) will have mined the first block. A sends it over to B.
But it takes 60 minutes for the block to arrive at computer B. In that time, B will have mined an