HMS Challenger spent three-and-a-half years peering into some of the remotest parts of our world’s oceans. Its groundbreaking voyage still has an impact today. It was once a private house, but now the imposing stone structure on Boswall Road, on the southern shore of the Firth of Forth in Edinburgh, is part of a palliative care hospice. The building shares its name with the one of the deepest parts of the ocean and two Nasa spacecraft. One was the command module for the Apollo 17 Moon mission while the other was part of the Space Shuttle fleet, and the first...