Kevin Peter Hand has delivered a beautiful portrayal of the science behind our search for life in alien oceans, and the connection to our precious ocean here on Earth. A must-read for all who gaze at the stars above and ponder the abyss below.--James Cameron In this delightful book, Kevin Peter Hand takes readers from the depths of Earth's oceans to those of the outer solar system, describing encounters with magical, alien-like creatures at the bottom of the Atlantic and offering informed speculations about what life could be like in the subsurface oceans of faraway moons. Recounting the story of how we discovered these alien oceans, he gives us a peek at the lives and personalities of some of the scientists who pieced together all the clues. His explanations are full of engaging analogies that will help general readers understand the science needed to think rigorously about life as we know it--and as we do not yet know it.--Jill Tarter, SETI Institute One of NPR's best books of 2020 Longlisted for the AAAS/Subaru SB&F Prize for Excellence in Science Books, Young Adult Science Book Award