Asteroids that pass close to Earth have become the focus of increased attention in recent years, partly because of the potential threat they pose to humanity.
But they are also a potential boon. For decades, science fiction writers and various space scientists have pointed out that asteroids offer a huge untapped source of valuable resources. Bringing just a small portion of this back to Earth could be a game changer for our planet.
And even if this stuff is too expensive to bring home, it could provide the raw materials for rocket fuel and perhaps even rockets themselves to be manufactured in space. Many visionaries have greedily eyed these resources in the hope that a new gold rush is just around the corner.