The first astronaut to walk on the moon was Neil Armstrong. This historic event took place during NASA's Apollo 11 mission on July 20, 1969. Armstrong stepped onto the lunar surface and famously declared, "That's one small step for [a] man, one giant leap for mankind." This moment marked a significant achievement in the Space Race and showcased human capabilities in space exploration. Edwin "Buzz" Aldrin followed him shortly after, becoming the second person to walk on the moon. The Apollo 11 mission remains one of humanity’s most celebrated accomplishments in the field of science and exploration.