Which astronaut wore an Omega Speedmaster on the Moon during Apollo 11?

Buzz Aldrin wore an Omega Speedmaster on the Moon during Apollo 11.

Apollo 11 astronauts Neil Armstrong and Buzz Aldrin carried Omega Speedmaster Professional watches. Armstrong left his watch inside the lunar module because the module’s electronic timing system had malfunctioned, so Aldrin’s watch became the first wristwatch worn on the lunar surface.

NASA had qualified the Speedmaster for crewed spaceflight in 1965 after demanding tests involving temperature, shock, vibration and vacuum. The watch had already flown on earlier American space missions, including Gemini missions.

The Speedmaster is therefore known as the “Moonwatch,” but the title does not mean only one astronaut used it. The important distinction is that Aldrin wore the first wristwatch on the Moon, while Armstrong’s watch remained in the lunar module.