Mars

 NY Times: You Don’t Need a Spaceship to Grow ‘Weird Little’ Martian Radishes - Scientists on this planet have worked out a variety of techniques to simulate the conditions of other worlds that are near and very far. By Sarah Scoles

He’s currently at work on a full agricultural system, including bacteria, earthworms and human excrement. The idea, Dr. Wamelink said, is “to boldly grow where no plant has grown before.” Today, Mars on Earth. Tomorrow, perhaps Mars itself.