When we think space, we often think about observation — watching the skies and figuring out what’s out there. But some people are already thinking about how to put the assets up in space to good use. One way to do that? Asteroid mining. It may sound like science fiction, but established companies such as Caterpillar and startups such as Planetary Resources are putting real money into it. Our two resident space nerds, Molly Wood and Kimberly Adams, talk about this to kick off our series looking at the economics of outer space.