Which astronaut was the second to walk on the Moon?

Buzz Aldrin was the second astronaut to walk on the Moon, following Neil Armstrong during Apollo 11. Aldrin stepped onto the lunar surface on July 20, 1969, about nineteen minutes after Armstrong.

Aldrin was Apollo 11’s lunar module pilot, while Armstrong served as mission commander. Together they spent more than two hours outside Eagle, collecting samples, deploying experiments, taking photographs, and inspecting the landing site in the Sea of Tranquility.

A common mix-up is confusing the second person on the Moon with the second Apollo mission commander to land there. Pete Conrad commanded Apollo 12, the second lunar landing mission, but Aldrin was the second human to walk on the Moon.