In the dark depths, four kilometres below the surface of the Pacific Ocean, scientists have found small clumps of rocks producing oxygen.

Previously scientists believed oxygen was created by living things using energy from the sun, so the idea of 'black oxygen' has thrown a curveball into our theory of how life on Earth may have began. It also begs the question - could life dependent on oxygen be more common outside of Earth?

Joining The Briefing to talk through what we know about the discovery, is science communicator and author of How to Save the Whole Blinkin' Planet, Lee Constable.