UNIDENTIFIED CORRESPONDENT: A CNN viewer wants to know, are there other elements on the moon or Mars which do not exist on earth?</s>MILES O'BRIEN, CNN CORRESPONDENT: We're not sure about Mars, but I can tell you this, on the moon there is an element that is very, very scarce here on earth that is actually relatively plentiful there. It's called helium three. It's an unusual isotope of helium which many scientists, many physicists believe could be used to create an efficient form of nuclear fusion. Nuclear fusion is the type of nuclear power generation that has sort of been the holy grail for nuclear scientists for many years because it doesn't generate any waste and creates a self-sustaining reaction. There's a lot of people who would tell you it's worthwhile going to the moon, if nothing else, to gather up and mine helium three and bring it back so that it will be possible to create these efficient fusion reactors. So, maybe there's one good case for going back to the moon.
Ask CNN: Do Other Elements Exist in Space Not on Earth