One third of the terrestrial sphere is lit, the terrestrial terminator, the hue of the sun, part of East Africa, photographed from the Apollo 11 probe during its first lunar landing mission. While astronauts Neil A. Armstrong, Commanding Officer, and Edwin E. Aldrin Jr., Lunar Module Pilot, were descending into the Lunar Module "Eagle" to explore the lunar region of the Sea of Tranquility, pilot astronaut Michael Collins of command module remained with the command and service modules "Columbia" in lunar orbit.