On July 20, 1969, at 4:17:43P.M. Eastern Daylight Time (20:17:43 Greenwich Mean Time), Neil A. Armstrong (1930–) and Edwin E. Aldrin Jr. (1930–) landed the lunar module Eagle on the moon’s Sea of Tranquility, and Armstrong radioed: “Houston, Tranquility Base here. The Eagle has landed.” Several hours later, when Armstrong descended the lunar module ladder and made the small jump between the Eagle and the lunar surface, he announced: “That’s one small step for man, one giant leap for mankind.” The article “a” was missing in the live voice transmission, and was later inserted in the record to amend the message to “one small step for a man.”