Recode Decode, hosted by Kara Swisher

Caleb Scharf: Living on Mars is complicated, actually

Caleb Scharf, the director of Astrobiology at Columbia University, talks with Recode's Kara Swisher about the under=discussed dangers humans would face in space and the rise of private space exploration, as championed by billionaires such as Elon Musk and Richard Branson. Scharf wrote a piece for Scientific American earlier this year, "Death on Mars."…