Splitting Earth, space weather and robotic dolphins

In this Planet Earth podcast, Sue Nelson hears about the birth of an ocean in the Afar depression in the Horn of Africa.  The continental crust is being ripped apart at a phenomenal rate – one metre every year over the last five years. In the not too distant future – well, not too distant in geological terms – we may see a new ocean in that region of Africa. That's if we're still around in ten million years' time.  Plus Richard Hollingham goes to Edinburgh to find out about the damage our nearest star wreaks on our planet during its unruly phases.  Later Sue hears about 'mechanical dolphins' in Antarctica, while Richard gives us a preview of the gruelling training he had to endure recently in preparation for a scientific expedition to the Arctic.