Could people breathe the air on Mars
Let's suppose you were an astronaut who just landed on the planet Mars. What would you need to survive? For starters, here's a short list: Water, food, shelter - and oxygen. Oxygen is in the air we breathe here on Earth. Plants and some kinds of bacteria provide it for us. But oxygen is not the only gas in the Earth's atmosphere. It's not even the most abundant. In fact, only 2