Fast-forward to several decades or a half-century from now, and it’s not inconceivable that humans could be living on Mars—building habitats, trundling around in rovers, mining the subsurface for resources, and producing the first generation of bipedal Martians.
Except, no one really knows if humans can successfully reproduce in space, whether that’s during spaceflight or on another planet. To be clear, having sex in (much) lower gravity is a simple physics problem. But a host of unknowns swirl around how space environments affect the actual biological sequences of events that must unfold with precision for a new human to grow, from fertilization to weaning.