Exploration of the Moon

• 1. Introduction

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  The Exploration of the Moon began not with a rocket, but with a rock carving. At Knowth in Ireland, a stone face dated to around 3,000 BCE bears what scholars consider one of the earliest known depictions of the Moon. From that rough mark on a stone, humanity spent the next five thousand years asking what the Moon was, how far away it sat, and whether anyone or anything lived there. The answers came slowly, then all at once.

  On the 14th of September 1959, a Soviet spacecraft called Luna 2 ended the guessing. It slammed into the lunar surface at 21:02:24 UTC, becoming the first human-made object to reach another world. That impact opened an era of physical exploration that would send humans to the surface, return rocks to laboratories on Earth, and eventually photograph terrain that no eye had ever seen. The questions that drive this story are deceptively simple: who went, what did they find, and what happens next?

• 2. Ancient Watchers

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  Enheduanna, an Akkadian high priestess and daughter of Sargon the Great, had the Moon tracked from her chambers. She is identified as the oldest named astronomer and poet in the historical record, and her devotion was directed at Nanna, the lunar deity whose crescent symbol had already appeared in art dating back to the 3rd millennium BCE. Long before anyone had a theory about what the Moon was made of, humans were counting it.

  Some researchers believe tally sticks from 20,000 to 30,000 years ago were used to track lunar phases. Cave paintings from up to 40,000 years ago show bulls and geometric shapes that may encode the same cycles. The Moon's influence on early writing is direct: aspects of the Moon were aggregated into lunar deities and then documented in symbols from the very first instances of writing in the 4th millennium BCE.

  The ancient Greek philosopher Anaxagoras was among the first in the Western tradition to strip the Moon of its divine status. He argued it was a giant spherical rock that reflected sunlight, a view so subversive that it contributed to his imprisonment and eventual exile. Aristarchus pushed further, attempting to calculate the Moon's actual distance from Earth. His estimate of 20 times Earth's radius fell far short of the real figure, though Eratosthenes had already measured Earth's radius with reasonable accuracy. Indian astronomer Aryabhata confirmed the reflection theory in his fifth-century text Aryabhatiya. Persian astronomer Habash al-Hasib al-Marwazi, working at the Al-Shammisiyyah observatory in Baghdad between 825 and 835, estimated the Moon's diameter as 3,037 km. By the Middle Ages, most learned people accepted that the Moon was a sphere, though many still believed its surface was perfectly smooth.

• 3. Mapping an Alien Surface

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  In 1609, Galileo Galilei drew one of the first telescopic images of the Moon and published it in his book Sidereus Nuncius. What he saw contradicted centuries of assumption: the surface was rough, marked by mountains and craters. Thomas Harriot made similar drawings around the same period, but his work was never published.

  The first true map of the Moon was produced by the Belgian cosmographer Michael van Langren in 1645. Two years later, Johannes Hevelius published Selenographia, the first book devoted entirely to the Moon. Hevelius named features after terrestrial counterparts, a system that stayed in use in Protestant countries until the eighteenth century. It was replaced by the nomenclature published in 1651 by Jesuit astronomer Giovanni Battista Riccioli, who named the large naked-eye dark patches after seas and the telescopic depressions after philosophers and astronomers. Those names largely survive today.

  In 1753, the Croatian Jesuit Roger Joseph Boscovich determined that the Moon had no atmosphere. Franz von Paula Gruithuisen proposed in 1824 that craters were formed by meteorite strikes. The scholarly debate about lunar life persisted well into the early 19th century: some major astronomers seriously entertained the idea that the surface contained vegetation and was inhabited by creatures called selenites. That speculation ended in 1837, when Wilhelm Beer and Johann Heinrich Mädler completed their four-volume Mappa Selenographica and companion book, firmly establishing that the Moon had no bodies of water and no appreciable atmosphere. The Moon had been mapped and stripped of its mysteries, at least for the telescopic era. The next leap would require leaving Earth entirely.

• 4. The Space Race Arrives

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  Luna 1, launched on the 4th of January 1959, was designed to hit the Moon. It missed, becoming instead the first probe to achieve a heliocentric orbit around the Sun. Two months later, on the 4th of March 1959, America's Pioneer 4 flew past the Moon. It was the only success among eight early American attempts.

  The Soviet Union moved faster. Luna 2 hit the surface in September 1959. Three weeks later, Luna 3 photographed the far side of the Moon on the 7th of October 1959, revealing a surface almost completely lacking in the dark maria so visible from Earth. These were firsts that jolted Washington. U.S. President John F. Kennedy delivered his response in a Special Message to Congress: 'I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth.'

  What followed was years of failure before success. Ranger 1 launched in August 1961, just three months after Kennedy's speech, and failed. It took six more failed Rangers before Ranger 7 finally returned close-up lunar photos in July 1964. The Soviet Union reached another milestone in 1966, achieving the first soft landings and taking the first surface photographs during the Luna 9 and Luna 13 missions. The United States countered with the Surveyor program, sending seven robotic spacecraft to the Moon; five soft-landed and investigated whether the dust layer was shallow enough for astronauts to stand safely. In September 1968, the Soviet Union sent tortoises on a circumlunar trip aboard Zond 5, followed by turtles on Zond 6 in November. On the 24th of December 1968, the Apollo 8 crew became the first humans to reach lunar orbit and see the far side with their own eyes.

• 5. Boots on the Regolith

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  Humans first stood on the Moon on the 20th of July 1969. Neil Armstrong and Buzz Aldrin, the crew of Apollo 11, touched down in the region of Mare Tranquillitatis. They left scientific instruments behind and carried lunar samples back to Earth. NASA's Apollo program would repeat that feat six times, all on the near side of the Moon.

  On the 17th of November 1970, the Soviet vessel Lunokhod 1 became the first robotic rover to operate on the lunar surface. The last human to stand on the Moon was Eugene Cernan, who walked there in December 1972 as part of Apollo 17. Moon rock was also returned to Earth by three Soviet Luna sample-return missions: Luna 16, 20, and 24. Luna 24 in 1976 was the final lunar mission by either the United States or the Soviet Union until the American Clementine mission in 1994. For nearly two decades, both powers turned their attention elsewhere: to other planets, space stations, and the Space Shuttle.

  Before the Moon race concluded, both nations had drafted plans for permanent lunar bases. The United States had preliminary projects named the Lunex Project and Project Horizon. The Soviets had conceived a multipurpose base called Zvezda, complete with mockups of expedition vehicles and surface modules. None were built. The infrastructure plans outlasted the political will that had conjured them, and the surface remained unvisited for a generation.

• 6. The New Explorers

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  Japan entered lunar exploration in 1990 with the Hiten spacecraft, becoming the third country to place an object in lunar orbit. JAXA launched the more capable SELENE orbiter, also known as Kaguya, in September 2007 to study the Moon's origin and geological evolution. In September 2023, JAXA launched the SLIM lander. It entered lunar orbit on the 25th of December 2023 and touched down on the 19th of January 2024 at 15:20 UTC, making Japan the fifth country to achieve a soft lunar landing. The lander survived four lunar days and three lunar nights despite power generation problems.

  India's Chandrayaan-1 orbiter, launched on the 22nd of October 2008, detected the widespread presence of water molecules in the lunar regolith, a finding with significant implications for future missions. Chandrayaan-2 followed in July 2019 but crashed during its final descent. Chandrayaan-3's lander Vikram succeeded on the 23rd of August 2023, touching down near the lunar south pole and making India the fourth country to achieve a soft landing and the first to reach the polar region.

  China's Chinese Lunar Exploration Program has moved with particular speed. Chang'e 3 soft-landed in December 2013, breaking a 37-year gap since Luna 24. Chang'e 4 landed on the far side on the 3rd of January 2019, deploying the Yutu-2 rover, which set a distance record for lunar surface travel and detected a dust layer up to 12 meters deep in parts of the far side. Chang'e 5 returned approximately 2 kilograms of lunar material to Earth on the 16th of December 2020. Chang'e 6, launched on the 3rd of May 2024, conducted the first sample return from the far side's Apollo Basin, with its returner landing in Inner Mongolia on the 25th of June 2024.

• 7. Next Steps

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  NASA's Artemis program, formulated in 2017, anchors the current push toward a crewed return. The program involves multiple Orion spacecraft flights and lunar landings planned across a window from 2022 to 2028. On the 3rd of November 2021, NASA designated a landing site in the lunar south polar region near the crater Shackleton, at a location termed the Shackleton Connecting Ridge, chosen for its near-continuous solar exposure and line-of-sight communication with Earth.

  Commercial activity has grown alongside government programs. The Google Lunar X Prize, launched in 2007, offered $20 million to the first private team to land a robotic spacecraft by March 2018; the prize went unclaimed when no finalist could meet the deadline. In August 2016, US-based startup Moon Express became the first private company ever granted permission to land on the Moon. NASA's Commercial Lunar Payload Services program, announced in November 2018 with nine competing companies, extended that commercial pathway further. Firefly Aerospace's Blue Ghost Mission 1 launched on the 15th of January 2025 and landed on the 2nd of March 2025.

  ESA's Moonlight Initiative plans a small network of communication and navigation satellites in lunar orbit, partly to support Artemis landings and partly to enable GPS-style positioning on the lunar surface. The timing demands of that navigation system led planners to propose a new lunar time zone, which resulted in the formal introduction of the Coordinated Lunar Time standard in 2024. Due to the Moon's lower gravity, time passes faster there by 56 microseconds per 24-hour period as measured from Earth.