Supersized El Nino strikes, and navigation app for the blind

Coming up: El Niño weather phenomenon will be 'exceptional' and last months, say forecasters. What should we know about it? We also hear from the team behind a successful at-home bladder cancer test, learn about the science behind the Nancy Grace Roman Telescope, and meet a Harvard researcher who has created an app to help visually impaired people get around. Like this podcast? Please help us by supporting the Naked Scientists (thenakedscientists.com/donate)