Horsey driverless cars and competitive cloning Unexpected Elements

The sight of horses running wild in a city leads panellist Tristan Ahtone in Helsinki to rethink how we rate horses' welfare, Chhavi Sachdev in Mumbai tells the story of the country that is cloning the Lionel Messi of horses for sport and presenter Marnie Chesterton finds out why roboticist Eakta Jain is studying horses to engineer better relationships between humans and autonomous vehicles. All that, plus the slippery record for the world's biggest snake, how the alphabet came to be and asteroid forcing scientists to reiterate 'it will not hit Earth'.