Mars is an empty planet, but that could change. Someday, it might have farms where fruit and vegetables could grow.
Growing food on Mars has always seemed hard. But scientists think they have found a way to do it. They put sheets(薄膜) of material on the ground. The sheets could change the cold, dry planet into land for farming.
Robin Wordsworth worked on the sheets at Harvard University in Massachusetts. He said the sheets could let people live on another planet. On Mars, the conditions are not good, though. Most importantly, the planet is cold and dry. The soil might have polluted parts, and the air does not have much nitrogen(氮气) that plants need to grow.
The sheets do not solve all the problems. Still, they could help to set up a place for plants. The plants would grow only under the sheets. So there is less worry about harming the rest of Mars. The sheets would cover the plants.
The scientists worked with sheets about an inch thick. Those allowed light through for plants. They also warmed the ground and trapped enough heat to melt ice on Mars. Placing the sheets over icy parts of Mars could let plants alive there. Their study was printed in Nature Astronomy. The sheets could be on the ground to grow water plants and they also could be hung. That would give room to plants to grow on land below them.
Wordsworth said, "You can imagine this being used in a number of ways. It could be used for visitors to Mars. Later it could be for people who live there. However, it's a pity that the sheets are being studied in the lab."
