The latest discoveries from the scientific and technological community with Chris Smith and Kat Arney from the Naked Scientists team. This week: Its travelled 4 billion miles. Its taken ten years. History is made as the Rosetta lander touches down on a comet. Closer to home we have news about our biological clocks. We find out how internet searches are predicting the outbreak of diseases. A study shows global warming is triggering more lightning strikes. We find out about cat genes. And we take a longer look at cancer research.