Crazy people go into mineshafts to see stars during the day, says University of Athens physicist Leonidas Resvanis, quoting the first‐century Roman naturalist Pliny the Elder. As Resvanis sees it, overcoming background light by peering at the sky from a hole in the ground was the forerunner to projects like the one he heads, the Neutrino Extended Submarine Telescope with Oceanographic Research. NESTOR is a detector designed to sit near the bottom of the Mediterranean Sea and monitor the heavens for neutrinos. In a report released this summer, the High Energy Neutrino Astrophysics Panel (HENAP), which was set up by the International Union of Pure and Applied Physics, gives its stamp of approval to stepping up such research and, specifically, to building a cubic‐kilometer‐scale neutrino detector deep under water in the Northern Hemisphere.