Adam Rutherford meets the Australian scientist behind a radical new technique to prevent mosquitoes from spreading the zika and dengue fever viruses to people. The method involves infecting mosquitoes with a harmless bacterium. The microbe doesn't kill the mosquitoes but stops the viruses multiplying inside them and spreads rapidly through wild mosquito populations. After 15 years of research, the mosquito control method is about to be deployed in large scale trials in urban areas in South America.

Also in the programme, the world's atmosphere crosses an iconic threshold as measured by the concentration of the greenhouse gas carbon dioxide: scientists get their hands on the rocks at the centre of the extinction of the dinosaurs: and details emerge of why the European Space Agency's recent Mars lander crashed onto the Red Planet.