Carl Sagan (1934–1996) was an astronomer, planetary scientist, author, and one of the most influential science communicators of the 20th century. He played key roles in NASA’s Mariner, Viking, and Voyager missions, helped design the Pioneer Plaque and Voyager Golden Record, and made groundbreaking contributions to planetary science, including insights into the atmospheres of Venus and Mars. Through his books, public lectures, and the landmark television series Cosmos: A Personal Voyage, Sagan brought the wonders of the universe into millions of homes, blending rigorous science with poetic storytelling. His reflections on the “Pale Blue Dot” photograph captured by Voyager 1 remain a timeless call for humility, unity, and care for our fragile planet.