Space

I love the idea and genuinely feel like the purpose or obligation of intelligent life is to spread and escape the confines of a single planet. But the first step has to be a stable environment here. If we can't maintain an ecology and atmosphere in literally the perfect conditions we're adapted for we have no business messing with other planets. That's not to say we shouldn't research and explore, but we're a long way from terraforming anything and Mars isn't exactly an awesome place to live even under ideal circumstances . A stable space station that's perminently habitable and self sufficient long-term is necessary before we can realistically consider further expansion. That would require us to have solved climate collapse and the mass extinction we've created which seems like a slim possibility at the moment.