

The math is pretty simple. We’re travelling at 25km/sec around the sun. You have to get that to zero to hit the sun. Getting to Jupiter means getting up to like 37km/sec (made up number). Way easier.
edit: I looked it up because it didn’t feel right. Outer planets move SLOWER the farther out you go because gravity is weaker and they don’t need as much angular momentum. So the math isn’t quite as simple as that. :)
I’ve said it before - an insurgency in the Rocky Mountains would be an absolute nightmare for an occupier.