A loja de ferragens de Marte pode ser um asteroide

One day people want to live on Mars. But they need metal to build things there. And they need fuel to come home. Today every piece comes from Earth. That is very slow and very expensive.

So scientists in Switzerland look at asteroids. Some asteroids are full of metal. The team studies which ones a normal spacecraft can reach. They find a small group of good ones. The trip costs little energy. And some of these rocks also have the material for rocket fuel.

But nobody mines an asteroid yet. A robot has to dig in almost zero gravity. A machine has to clean the metal in space. Both things are only ideas today. Still, the study shows one thing clearly: the problem is hard, not impossible.