These two terms are often used interchangeably, but there is a difference between them. When shopping at your local gardening center or plant nursery, you'll probably come upon hefty bags of potting ...

But is it possible to actually grow food in Martian soil? Yes, and not just potatoes, says Bruce Bugbee, a real-life botanist and NASA scientist. In "The Martian," Watney grows his own food by ...