A company called SpaceX has plans to send humans to live on Mars by 2022, but there’s still a lot of problems. For instance, we’re still not sure whether the low gravity on small planets might be bad for bone density: our bones might get weaker over time and leave us vulnerable to fractures. NASA is serious abut going to Mars too in the 2030s – this is a really exciting time in space exploration. Who knows if we’ll ever devise ways of living on other planets besides Mars? Venus is too hot, Mercury too close to the Sun, but the moons of Jupiter and Saturn might one day be something to consider.