Earth has just one Moon, and on average the Moon is about 239,000 miles (384,000 kilometers) from Earth, although its distance changes as it moves on an oval orbit, from about 363,300 kilometers (225,700 miles) at its closest on average to about 405,500 kilometers (252,000 miles) at its farthest. The Moon is about 2,160 miles (3,475 kilometers) across, and it has a rocky surface covered with craters, which were made when space rocks crashed into it.

The first known drawing of the Moon made through a telescope was by Thomas Harriot, dated July 26, 1609, a few months before Galileo's drawings, and Galileo used a telescope to see that the Moon has mountains and craters and is not smooth.

We always see the same side of the Moon from Earth. The Moon spins exactly once for every trip it makes around Earth, an arrangement called tidal locking, and Earth's pull on the young Moon slowed the Moon's spin until it matched its orbit.

Even though the same face always points toward Earth, slight rocking and wobbling motions called librations let observers on Earth see as much as about 59 percent of its surface over time. The Moon's east-west wobble, called libration in longitude, happens because its orbit is slightly oval: it travels faster when closer to Earth and slower when farther, while its spin stays steady.

Until a Soviet spacecraft flew past in 1959, nobody had seen the far side of the Moon. Luna 3, a Soviet spacecraft, took 29 photographs of the far side of the Moon; people sometimes call the far side of the Moon the dark side, but that is misleading, because the far side gets sunlight too. The far side of the Moon never faces Earth, so a spacecraft working there needs a relay satellite to send messages to Earth.

China's Chang'e-4 spacecraft made the first soft landing on the far side of the Moon. As of November 2026, China's Chang'e-6 mission has brought back 1,935.3 grams of Moon samples from the far side, the first samples ever returned from there.

The Soviet Luna 2 was the first spacecraft to reach the surface of the Moon. It did not land gently: it made a hard-impact crash landing, and the impact destroyed the spacecraft, and instruments on Luna 2 returned data that helped show the Moon has no significant magnetic field and no radiation belts like Earth's. The Soviet Luna 9 lander transmitted the first photographs taken from the surface of the Moon. Apollo 8 in 1968 was the first crewed mission to orbit the Moon, and people have landed on the Moon on six Apollo missions: Apollo 11, 12, 14, 15, 16 and 17.

Apollo 11, the mission that first landed people on the Moon, lifted off on July 16, 1969. Neil Armstrong and Buzz Aldrin landed on the Moon in Eagle, while Michael Collins stayed in orbit in the command module Columbia. Armstrong flew the last part of the landing partly by hand and set Eagle down in the Sea of Tranquility. In 1969 he became the first person to walk on the Moon, and as he stepped onto it he said, "That's one small step for man, one giant leap for mankind."

On Apollo 17, Eugene Cernan and Harrison Schmitt spent just over 22 hours outside on the Moon's surface. Near the rim of Shorty Crater, Schmitt spotted orange soil; when a fender on their moon car, the lunar rover, broke, the astronauts fixed it with duct tape and taped-together maps.

The Apollo astronauts brought back 842 pounds (382 kilograms) of Moon rocks and soil, and Moon rocks brought back by Apollo match Earth rocks very closely in their chemistry, a clue about how the Moon formed. Scientists think the Moon formed when an object about the size of Mars crashed into the young Earth. This giant-impact idea is the leading explanation; older ideas, that Earth captured the Moon or that it formed beside Earth from the same debris, fell out of favor after Apollo brought back Moon rocks. The astronauts also left instruments behind: Apollo 11 astronauts left a mirror array, a retroreflector, on the Moon, and scientists on Earth bounce laser pulses off it to measure the distance to the Moon. The mirrors are still used today to track its orbit, and seismometers left by Apollo astronauts recorded 28 shallow moonquakes between 1969 and 1977.

There is water ice on the Moon, hidden in dark craters near the poles where the Sun does not shine. India's Chandrayaan-3 made the first soft landing near the Moon's south pole, and India became the fourth nation to land on the Moon.

Artemis II was a trip around the Moon with astronauts on board. As of November 2026: Artemis II launched on April 1, 2026, from Kennedy Space Center in Florida. Its crew were NASA astronauts Reid Wiseman, Victor Glover and Christina Koch and Canadian Space Agency astronaut Jeremy Hansen. As of November 2026: the Artemis II crew set a new record for the greatest distance humans have traveled from Earth.

As of November 2026, no one has walked on the Moon since Apollo 17 left in December 1972. As of November 2026, the Moon is the only place beyond Earth that people have ever visited.

Words to know

• librations: slight wobble
• retroreflector: light-returning mirror
• relay: passes messages on
• seismometers: quake detectors