Distance and Latency would be a big problem for mining. For transactions, it will simply mean you have a delay in sending them and confirming them. Still that would not be practical if other planets are involved. Bitcoin was never designed for anything other than the planet Earth and possibly anything beyond 1 or 2 minutes away at the speed of light / radio.
Unless if they will go ahead and invest to create satellites that are meant only to be a mediator to strengthen the signals just like in a basic router and network systems. There are those we call the bridges and signal amplifiers that could be use if the distance is quite too far enough to still make the transaction faster and efficient.
But in the first place, why would we need bitcoin and crypto outside of the planet? For me, we should first focus on developing and enhancing bitcoin and crypto system here before we start to implement it outside of our vicinity.