In the 2015 film “The Martian,” Matt Damon’s character is a scientist left behind on Mars. He has limited food supplies and not much water. He tries to figure out how to survive so he can be rescued. Luckily, he knows how to grow things. And one of the things he grows is a potato plant. A year later, scientists in Peru and NASA scientists in California started working together on growing potatoes in a harsh location similar to Mars. They built a container where they could simulate the conditions on Mars. The salty soil came from the southern coast of Peru, where there is very little rain. Inside the “Mars-in-a-box,” the scientists made the air pressure similar to what it is like at 6,000-meters, decreased the temperature below zero, and added carbon monoxide to the air. They made a lighting system that followed Mars’ daytime and nighttime. They planted 65 types of potato plants, and waited. After a while, four of them grew. Later, the scientists took the strongest of the four plants and tried again. This time, they used crushed rocks instead of soil. The plant still grew.