Cloudy lines in the sky, caused by aircraft engines, are called contrails. They're harmful to the environment. Now a project is underway, using AI, to reduce the amount generated. It's called Operation Blue Skies, and we speak to Google about their involvement.

Also this week: we look at three very different approaches taken by manufacturers to help children and adults have a healthy relationship with mobile phones. And AI detectors - how do they work?

Presenter: Shiona McCallum Producer: Tom Quinn

(Photo: A large four engine passenger jet flies at high altitude. The sky is blue, and the jet engines are emitting white cloudy trails, known as contrails. Credit: Getty Images)