The Far Side of the Moon: Why We Never See It, What’s There, and Why It’s Not Dark

The far side of the moon is the hemisphere humans never saw with our own eyes until December 1968. It is not dark, it is not mysterious in the supernatural sense, and Pink Floyd had nothing to do with naming it. Below is why we always see the same face, what is actually on the side we never see, and the missions that have finally mapped, landed on, and brought rocks back from the side of our nearest neighbor that we cannot see from the kitchen window.

Why We Always See the Same Side

The Moon is tidally locked to Earth. That phrase has a precise meaning. The Moon rotates on its axis exactly once for every full orbit it makes around Earth. Both periods take 27.3 days. The result: the same hemisphere is always pointed at us, and the other half is always pointed away.

This did not happen by accident. Earth’s gravity pulls a little harder on the side of the Moon facing us than the side facing away, which created tidal bulges in the Moon’s rocky body billions of years ago. Over time, that gravitational drag slowed the Moon’s rotation until the spin matched the orbital period. Once the two locked together, they stayed there. The same process is gradually slowing Earth’s rotation; days are getting longer by about 1.7 milliseconds per century.

Tidal locking and lunar phases are different things. Tidal locking determines which face we see. Phases (waxing, full, crescent) determine how much of that visible face is lit by the Sun. For the TikTok trend that pairs people by their birth phase, see moon phase compatibility. The Moon shows the same hemisphere even at new moon, when the lit side has rotated to face away.

“Dark Side” Is a Misnomer

The far side gets exactly as much sunlight as the near side. Both hemispheres go through a 14-day day and a 14-day night every lunar month. When the Moon is in the new-moon phase from our perspective, the far side is in full sunlight. When the Moon is full from our perspective, the far side is in darkness.

So why “dark side”? In the older astronomical literature, “dark” meant “unseen” or “unknown,” not “unlit.” Once humans started flying past the Moon and photographing the far hemisphere, the language gradually shifted. Most working astronomers today say far side. Pink Floyd’s 1973 album, despite popular interpretation, is about mental health, lunacy, and time, not lunar geography.

We Actually See 59 Percent of the Moon

The Moon’s orbit is slightly elliptical and slightly tilted relative to its rotation axis. The combination produces a small wobble called libration that lets observers on Earth peek over the lunar limb (edge) by a few degrees in different directions over the course of a month. Across many cycles, libration adds up. Earth-based observers can eventually see about 59 percent of the lunar surface. That leaves roughly 41 percent of the Moon truly invisible from Earth.

First Photos: Soviet Luna 3, October 1959

The Soviet Luna 3 spacecraft swung past the Moon on October 7, 1959, carrying a small dual-lens camera, an automatic film-development system, and a scanner that converted negatives into radio signals beamed back to Earth. The 29 photographs returned were grainy but historic. They showed for the first time the hemisphere humans had never seen. The far side, the photos revealed, looked profoundly different from the near side. Far fewer dark plains. Far more craters. Soviet scientists named major features in the data, and several names (Mare Moscoviense, the Sea of Moscow) are still in use.

First Human Eyes: Apollo 8, December 1968

Frank Borman, James Lovell, and William Anders became the first humans to see the lunar far side with their own eyes when Apollo 8 entered lunar orbit on December 24, 1968. Anders described the surface as “a vast, lonely, forbidding expanse of nothing.” On the same mission, looking the other direction, Anders took the famous Earthrise photograph. The first humans ever to see Earth as a whole planet were also the first to see the lunar far side.

First Landing: China’s Chang’e 4, January 2019

For 50 years after Apollo 8, no spacecraft had touched the far side. The challenge is not landing technology. The challenge is communication. Direct radio signals between Earth and the lunar far side are blocked by the Moon itself. Any far-side mission requires a relay satellite parked in a position where it can see both Earth and the lunar far side at the same time.

China’s Chang’e 4 spacecraft made the first soft landing on the far side on January 3, 2019, in the Von Karman crater inside the South Pole-Aitken basin. It used a relay satellite, Queqiao, parked at the Earth-Moon L2 Lagrange point, to bounce signals between Earth and the lander. The Yutu-2 rover then drove away from the lander and continued exploring. Yutu-2 was still operational years later, the longest-running rover in lunar history.

First Sample Return: China’s Chang’e 6, June 2024

Chang’e 6 returned to Earth on June 25, 2024, carrying about 1.93 kilograms (roughly 4.3 pounds) of rock and soil collected from the South Pole-Aitken basin on the far side. It was the first sample return from the lunar far side in the history of space exploration. Initial analysis is rewriting the geological history of the Moon, including the timing of late lunar volcanism on the far hemisphere.

The Geology Differs From the Near Side

The two hemispheres look different because they are different.

Crust thickness. The far-side crust averages about 50 kilometers thick. The near-side crust averages about 30 kilometers. Why is still debated; one leading theory involves a giant impact early in lunar history that thinned one hemisphere.

Maria coverage. “Maria” are the dark, basaltic plains that form the man-in-the-moon face. They cover about 31 percent of the near side and only about 1 percent of the far side. Thicker far-side crust prevented underground basalt from reaching the surface, so the far side stayed cratered and rugged instead of getting flooded with lava.

Crater density. The far side has noticeably more craters per square kilometer, partly because it had no widespread volcanic resurfacing to erase the older impact record.

South Pole-Aitken: The Biggest Crater in the Solar System

The far side hosts the largest confirmed impact crater in our entire solar system. The South Pole-Aitken basin is roughly 2,500 kilometers (1,550 miles) across and 8 kilometers (5 miles) deep at its center. It formed roughly 4.3 billion years ago. NASA gravity-mapping data has detected a dense mass beneath the basin, possibly the metallic core of the asteroid that produced the impact, that is roughly five times larger than the Big Island of Hawaii.

Why the Far Side Matters for Future Exploration

Two reasons. First, the lunar far side is shielded from all of Earth’s radio noise. That makes it the best location in the inner solar system for sensitive radio astronomy. NASA’s Lunar Crater Radio Telescope concept proposes to suspend a 1-kilometer-wide wire mesh inside a far-side crater, creating the largest radio telescope ever built and one positioned to listen for signals from the universe’s earliest era, the cosmic dark ages.

Second, the far side hosts the South Pole-Aitken basin, which contains some of the deepest exposed rocks on the Moon. Sampling them gives planetary scientists access to the lunar interior without having to drill kilometers down. NASA’s Artemis program plans to land astronauts near the lunar south pole, and several future Chinese missions target the far side specifically.

Frequently Asked Questions

Why do we always see the same side of the moon?

The Moon is tidally locked to Earth. Its rotation period (27.3 days) matches its orbital period exactly, so the same hemisphere always faces us. Earth’s gravity slowed the Moon’s rotation over billions of years until the two periods synchronized.

Is the far side of the moon dark?

No. Both hemispheres receive equal sunlight. “Dark” originally meant “unseen” or “unknown” in older astronomical writing, not “unlit.” When the Moon looks new from Earth, the far side is in full sunlight; when the Moon is full from Earth, the far side is in darkness.

What was the first photo of the far side of the moon?

The Soviet Luna 3 spacecraft took the first photographs of the far side on October 7, 1959. The 29 grainy images showed a hemisphere with far fewer dark plains and far more craters than the near side.

Has anyone landed on the far side of the moon?

No humans have. China’s robotic Chang’e 4 spacecraft made the first soft landing on January 3, 2019, in the Von Karman crater. China’s Chang’e 6 returned the first far-side soil samples to Earth on June 25, 2024.

What is the largest crater on the moon?

The South Pole-Aitken basin on the lunar far side. It measures about 2,500 kilometers (1,550 miles) across and 8 kilometers (5 miles) deep, making it the largest confirmed impact crater in the solar system. It formed approximately 4.3 billion years ago.

How much of the moon can we see from Earth?

About 59 percent of the lunar surface over time, thanks to a wobble called libration that lets us peek slightly past the lunar edge in different directions. The remaining 41 percent of the Moon is truly invisible from Earth without spacecraft.