Journey seven miles below the surface of the ocean in this thrilling moment-by-moment recounting of astronaut and oceanographer Kathryn Sullivan's real-life deep dive to the "bottom of the world." This book is brimming with STEM concepts and heart. What is it like to visit the deepest place in the ocean? In childhood, Kathryn Sullivan was drawn to the blank spaces on the map. She boosted her passion for exploration with curiosity, hard work, and science education. Finally, she had the opportunity to study the depths of the Marianas Trench, a trip that would require a lot of study and precise preparations. Get the inside scoop on everything deep dive, from how submersibles are engineered to the nitty-gritty of planning an ocean-floor expedition. Travel with Sullivan in the submersible Limiting Factor into bright waters where dolphins and turtles glide; down to the murky twilight zone, home of lantern fish and deep-sea squid; down, down, to the opaque darkness that no sunlight penetrates . . . with three hours of descent still to go. Through science-rich text, colorful illustrations, and striking photographs, Kathryn Sullivan and author-illustrator Michael J. Rosen take young explorers on an astonishing journey to one of the most mysterious places on Earth.