Multiple choice Sea of Tranquility is: a place where is calm prevails a sea where there is the least disturbance a place on moon where American astronauts landed None of the above Reveal answer Fill a bubble to check yourself C Correct answer Explanation The Sea of Tranquility (Mare Tranquillitatis) is a lunar mare on the Moon's surface. It was the landing site of Apollo 11, where Neil Armstrong and Buzz Aldrin became the first humans to land on the Moon on July 20, 1969.