“Of course Pluto is a planet: It's massive enough to have its shape controlled by gravity rather than material strength, which is the hallmark of planethood.”

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.