Would you want to meet an alien?

What might an experimental petrologist (someone who makes rocks in the lab) and an immunologist (someone who studies the body's defence system) have in common? Well, it turns out, a shared interest in iron might be one thing. And what does all this have to do with aliens, and, specifically, whether you would want to meet one? Well, you'll have to listen to find out! With Prof Jon Wade from the Department of Earth Sciences.