This photo shows a full moon from up close as the astronauts--Neil Armstrong (commander), Buzz Aldrin (lunar module pilot), and Michael Collins (command module pilot)--began their homeward journey on that July 21.
Describing his view of the moon upon arrival in the neighborhood a day or so earlier, Collins (in a NASA account) offered this description: "Our first shock comes as we stop our spinning motion and spin ourselves around so as to bring the moon into view. We have not been able to see the moon for nearly a day now, and the change is electrifying....
"To begin with, it is huge, completely filling our window. Second, it is three-dimensional. The belly of it bulges out toward us in such a pronounced manner that I almost feel I can reach out and touch it."
During the lunar module's final 12-minute powered descent to the surface, the astronauts and Mission Control back on Earth had to contend with some unsettling program alarms from the flight computers. Said Collins: "My checklist says [program alarm] 1202 is an 'executive overflow,' meaning simply that the computer has been called upon to do too many things at once and is forced to postpone some of them."
Aldrin: "In the final phases of the descent after a number of program alarms, we looked at the landing area and found a very large crater. This is the area we decided we would not go into; we extended the range downrange. The exhaust dust was kicked up by the engine, and this caused some concern I that it degraded our ability to determine not only our altitude in the final phases but also our translational velocities over the ground. It's quite important not to stub your toe during the final phases of touchdown."