“No one predicted Mercury would be a planetary core with the mantle stripped off. No one predicted volcanoes on the Jovian moons, or oceans on the inside of them. I can tell you, for every single planet, huge 'we never guessed that' things.”

American engineer, planetary scientist, and private astronaut

Alan Stern is an American engineer, planetary scientist, and private astronaut. He is best known as the principal investigator of the New Horizons mission to Pluto and as chief scientist at Moon Express. Stern has built a career in space science and exploration, with work that spans engineering, planetary research, and commercial space efforts. He is associated with projects focused on Pluto and the Moon, reflecting an interest in exploration, scientific discovery, and the expanding reach of private spaceflight.