If humans are going to live on Mars, we’re going to need to learn how to grow plants in the planet’s thin atmosphere, poor soil, severe cold, and total lack of water. This environment will put plants into a severe state of stress and shut down their metabolism, but NASA scientists think they’ve got strategies to help them cope. By introducing genes from extremophile microbes that can withstand severe changes in environment, scientists are hoping to modify plants so they won’t shut down their metabolism in response to stress.