Space: Mining's next frontier?

Private companies are becoming increasingly involved in outer space; in the last couple of months there has been the first commercial rocket deliver supplies to the International Space Station and even the announcement of plans to dig mines on asteroids.

But what right do they have to lay claim to these resources? As it stands, an international treaty dating from the Cold War says "celestial bodies" belong to all mankind. And as Ray Furlong reports, there are now growing calls to resolve the question of property rights in the stars.