Here’s how future Mars residents might breathe freely

Here’s how future Mars residents might breathe freely

A spacecraft slowly descends to the surface of Mars. Once arid and lifeless, the Red Planet now features a lush, green landscape. Passengers watch as a city comes into view. People walk along busy streets, venture into the local park and breathe the Martian air. Many science fiction writers have envisioned futures like this for Mars. In these stories, humans use so-called terraforming technology to make other planets more Earthlike.   Anyone liv…