Who owns asteroids or the moon?

Mr Bentwick, according to this article in the New Scientist you shouldn't get too excited just yet.

In just under two years, Planetary Resources says it will launch the first of a series of space telescopes into low-Earth orbit in a bid to spot nearby asteroids of a size and mineral composition potentially worth mining. When a strong candidate is found, it plans to dispatch a robotic probe to assess the asteroid's precious metal content, with platinum a priority. If that is found, yet-to-be developed robots will be dispatched to mine it. If it is small enough, the asteroid could be brought into an Earth orbit first, to make the process easier. 

...Moon Express, a start-up based in Las Vegas, is planning to prospect the moon for platinum and other metals deposited on its surface by meteorites. 

... 

[The UN's Outer Space Treaty of 1967] specifically prohibits states from making territorial claims in space. "States cannot claim rights over an asteroid," says Joanne Wheeler, a lawyer at London legal practice CMS Cameron McKenna and a UK government adviser on the UN's Committee on the Peaceful Uses of Outer Space.

Note however that this view - or the view that this also applies to private actors - is not uncontested.