As we orbit the present, the future of cryptocurrency looms like a nebula full of potential and mysteries. Imagine an era where digital currencies transcend earthly bounds, becoming as commonplace and fluid as streaming stars across the cosmos. In this not-so-distant future, we could witness payments that race across the solar system at light-speed, with decentralized ledgers capturing our interplanetary transactions. Here, on the terraformed plains of Mars, a coffee purchase might just cost ...