While his Apollo 11 crewmates Neil Armstrong and Buzz Aldrin became the first humans to walk on the moon, Michael Collins was dutifully orbiting the lunar surface in the command module Columbia. Once back on Earth, the trio — along with 27 others — were awarded gold Omega Speedmaster watches to celebrate the achievement and the timepiece's role in it. Collins' watch has now come up for auction. It measures 40mm in diameter, with an 18K gold case and matching bracelet, a gold dial, a burgundy tach insert in the bezel, and an inscription on the back that reads "Astronaut Michael Collins, Gemini 10 - Apollo 11, No. 19, to mark man's conquest of space with time, through time, on time". It's accompanied by a handwritten note from Collins, who has kept the watch in his possession over the last 50+ years.