Misha Glenny and guests discuss one of the wonders of the natural world. In 1875 in the western Pacific, the crew of HMS Challenger discovered the Mariana Trench which turned out to be deeper than Everest is high, by two kilometres. Trenches like Mariana form when one tectonic plate slips under another and heads down and there are around fifty of them globally. While at one time some thought it was too dark and deep for life there and others wildly imagined monsters, the truth has turned out to be much more surprising. With Heather Stewart, Director of Kelpie Geoscience and Associate Professor at the University of Western Australia Jon Copley Professor of Ocean Exploration and Science Communication at the University of Southampton And Alan Jamieson Director of the Deep Sea Research Centre at the University of Western Australia Producer: Simon Tillotson Reading list: Susan Casey, The Underworld: Journeys to the Depths of the Ocean (Doubleday, 2023) Jon Copley, Deep Sea: 10 Things You Should Know (Orion Books, 2023) Hali Felt, Soundings: The Story of the Remarkable Woman Who Mapped the Ocean Floor (Henry Holt & Co, 2012) M.E. Gerringer, ‘Pseudoliparis swirei: A newly-discovered hadal liparid (Scorpaeniformes: Liparidae) from the Mariana Trench’ (Zootaxa 4358 (1), 161-177, 2017) A.J. Jamieson, The Hadal Zone: Life in the Deepest Oceans (Cambridge University Press, 2015) A.J. Jamieson et al., ‘A global assessment of fishes at lower abyssal and upper hadal depths (5000 to 8000 m)’ (Deep-Sea Research Part 1. 178: 103642, 2021) A.J. Jamieson et al., ‘Fear and loathing of the deep ocean: Why don’t people care about the deep sea?’ (ICES Journal of Marine Science. 78: 797-809, 2020) A.J. Jamieson et al., ‘Microplastic and synthetic fibers ingested by deep-sea amphipods in six of the deepest marine environments on Earth’ (Royal Society Open Science, 6, 180667, 2019) A.J. Jamieson et al., ‘Bioaccumulation of persistent organic pollutants in the deepest ocean fauna’ (Nature Ecology and Evolution. 1, 0051, 2017) V.L. Vescovo et al., ‘Safety and conservation at the deepest place on Earth: A call for prohibiting the deliberate discarding of nondegradable umbilicals from deep-sea exploration vehicles’ (Marine Policy. 128, 104463, 2021) J.N.J. Weston et al., ‘New species of Eurythenes from hadal depths of the Mariana Trench, Pacific Ocean (Crustacea: Amphipoda)’ (Zootaxa. 4748(1): 163-181, 2020) In Our Time is a BBC Studios Production Spanning history, religion, culture, science and philosophy, In Our Time from BBC Radio 4 is essential listening for the intellectually curious. In each episode, host Misha Glenny and expert guests explore the characters, events and discoveries that have shaped our world.