Our planet, for all it’s troubles and harsh realities, is pretty kind to us. As long as our lungs are working okay, taking a breath seems like a sure thing. Space stories like The Martian put our reliance on our perfectly balanced air in perspective, and help us feel grateful that, for most of us, the stresses of our lives don’t involve second-to-second survival decisions. We’re also lucky we don’t have to nearly blow ourselves in an attempt to grow calories for sustenance.