Apollo 11 Moon landing, Neil Armstrong's first step (1969)

On July 20, 1969, the Apollo 11 lunar module Eagle landed in the Sea of Tranquility, carrying Neil Armstrong, Buzz Aldrin, and Michael Collins. Neil Armstrong became the first human to walk on the Moon about six hours and 39 minutes after landing, saying, "One small step for a man, one giant leap for mankind," and Buzz Aldrin joined him 19 minutes later. The crew left a silicon disc in the Sea of Tranquility carrying messages from 73 nations. Television broadcasts of the landing reached a global audience believed to be about 650,000,000 viewers. Armstrong photographed Buzz Aldrin on the surface in image AS11-40-5902, capturing the first footprints on another world. The Apollo Guidance Computer software later grew to roughly 145,000 lines of code, and the surface work and specimens gathered by Armstrong and Aldrin continued to fuel scientific research long after the mission. The last time humans visited the Moon was in 1972.