Dear Science: Deadly chemicals, exoplanet discoveries and dodgy chicken sandwiches

AUT’s Allan Blackman returns this week for Dear Science. He talks to Ximena about the lethal chemical that was used to kill North Korean leader’s estranged brother, NASA’s recent discovery of seven Earth-sized worlds orbiting a nearby star, and also about a new Canadian investigation that’s found Subway “chicken” contains an alarming low amount of, well, actual chicken.