The Apollo program, also known as Project Apollo, was the United States human spaceflight program led by NASA, which landed the first humans on the Moon in 1969. Apollo was conceived during Project Mercury and executed after Project Gemini. It was conceived in 1960 as a three-person spacecraft during the Presidency of Dwight D. Eisenhower. Apollo was later dedicated to President John F. Kennedy's national goal for the 1960s of "landing a man on the Moon and returning him safely to the Earth" in an address to Congress on May 25, 1961.
Apollo 11 was a spaceflight conducted from July 16 to 24, 1969, by the United States and launched by NASA. It marked the first time that humans landed on the Moon. Commander Neil Armstrong and Lunar Module pilot Buzz Aldrin landed the Lunar Module Eagle on July 20, 1969, at 20:17 UTC, and Armstrong became the first person to step onto the Moon's surface six hours and 39 minutes later, on July 21 at 02:56:15 UTC. Aldrin joined him 19 minutes later, and they spent about two and a quarter hours together exploring the site they had named Tranquility Base upon landing. Armstrong and Aldrin collected 47.5 pounds (21.5 kg) of lunar material to bring back to Earth as pilot Michael Collins flew the Command Module Columbia in lunar orbit, and were on the Moon's surface for 21 hours, 36 minutes, before lifting off to rejoin Columbia.
The Moon is Earth's only natural satellite. It orbits around Earth at an average distance of 384,399 kilometres (238,854 mi); about 30 times Earth's diameter. Its orbital period and its rotation period are synchronized at 29.5 days by Earth's gravity pulling on the Moon. This makes the Moon tidally locked to Earth, always facing it with the same side. The Moon's gravitational pull produces tidal forces on Earth, which are the main driver of Earth's tides.
Mare Tranquillitatis is a lunar mare that sits within the Tranquillitatis basin on the Moon. It contains Tranquility Base, the first location on another celestial body to be visited by humans.
Neil Alden Armstrong was an American astronaut and aeronautical engineer who, as the commander of the 1969 Apollo 11 mission, became the first person to walk on the Moon. He was also a naval aviator, test pilot and university professor.
Buzz Aldrin is an American former astronaut, engineer and fighter pilot. He made three spacewalks as pilot of the 1966 Gemini 12 mission, and was the Lunar Module Eagle pilot on the 1969 Apollo 11 mission. He was the second person to walk on the Moon after mission commander Neil Armstrong. Following the deaths of Armstrong in 2012 and pilot Michael Collins in 2021, he is the last surviving Apollo 11 crew member. Following Jim Lovell's death in 2025, Aldrin became the oldest living astronaut.