Mosquito pesticide failing

Mosquito pesticide failing - prevention of dengue fever and other diseases at risk. Dangerous bird flu evolving fast - researchers are learning why bird flu is persisting and spreading fast round the world, and assess the threat to humans. Drilling for ancient ice in the Antarctic - Roland talks to one of the team drilling kilometres into an ancient, frozen record of past climate, Martian rock store opens - NASA's Mars Perseverance rover is stashing rock samples future missions could bring back to Earth. Image credit: Shinji Kasai Producer: Roland Pease Assistant Producer: Sophie Ormiston