I don't think that there is a need for a separate blockchain for each planet. Bitcoin blockchain itself is enough for all.
The blockchain can work within our solarsystem but the mining part world be on Earth+moon due to synching for the miners.
I do not think the system works if we go to further stars and solar systems.
The transmission delay is far too long.
the ten nearest stars are
https://www.astronomy.com/science/explore-the-10-nearest-stars/Proxima Centauri 4.25 light years
The Alpha siblings 4.35 light years
The runaway star Barnard’s Star 6.0 light years
The next nearest star is the red dwarf Wolf 359 7.9 light years
Lalande 21185 8.0 light years
Sirius A is 8.6 light years
BL Ceti and UV Ceti binary 8.6 light years
so lets argue we figure out how to safely get clsoe to the speed of light in a space ship (I doubt this)
my guess is we continually go faster thil we get close then we slow down to a more normal speed
So maybe we end up doing 40% which means travel to the closest star would be 10 years by ship
I doubt this happens unless there is better science and we can trick fuck the speed of light laws.
So just on the solar system using mars earth Venus and some moons could happen and BTC with earth+ moon mining could happen
anything else or further ETH and Solana look better
I think the stars will be out of the choice since even light years away, getting close to them is impossible, if there are some explorations that could happen, they will be burned if they get closer to it. But as for the nearest planets, there is a possibility that advanced technology could get there. And that's already beyond my imagination. How could it happen? To be honest, it's a good discussion and things like this that a normie like me haven't thought is becoming exciting if ever some rich guy that's also enthusiastic about it could bring this into reality, maybe Elon is the only guy that could do this but I know he's got a lot of haters but he's got the resources or maybe Richard Branson's virgin galactic or Jeff Bezos' blue origin.