Plastics in the oceans and tracking satellites

Scientists recently found plastics floating in some of the most remote and inaccessible seas in the world – just off the coast of Antarctica.  Although it clearly looks ugly in such a pristine environment, scientists are more concerned about the major role plastics play in moving alien species around the world.  Richard Hollingham goes to the north Norfolk coast to speak to an expert on ocean plastics from the British Antarctic Survey to find out more.  Later, Sue Nelson goes to the Natural Environment Research Council's Space Geodesy Facility at Herstmonceux in Sussex to find out how it uses lasers to pinpoint satellites.