The near side as seen from Earth
The Moon · the far side
The Moon’s familiar dark plains almost disappear when you turn it around. Turn the globe to see what replaces them, how the crust differs underneath, and where two Chinese spacecraft set down on the side turned away from Earth.
The near side
The dark patches visible to the naked eye are plains of solidified lava. Seventeenth-century maps called them seas, maria in Latin, and the names stuck: Mare Imbrium, Mare Tranquillitatis, Mare Crisium. On the map drawn by the team behind the LROC camera, they cover about 30% of the hemisphere that faces Earth.
The Moon spins once on its axis in exactly the time it takes to circle Earth once, about 27.3 days. That is why Earth always sees the same face. NASA
The edge
The dashed line is the 90° east meridian, the limit of the hemisphere turned towards Earth. Mare Crisium, to its left, shows from Earth as an oval near the edge of the disc.
The edge is not fixed. The Moon’s orbit is elliptical and its spin axis is tilted to the plane of the orbit, so from Earth the Moon appears to rock slightly, showing small areas beyond the line, one margin at a time. This is called libration. Over time, as much as 59% of the Moon’s surface can be seen from Earth this way. The other 41% can never be seen from here. NASA
The far side
The same Moon, under the same light. The dark plains have almost gone: on the same map they cover about 2% of this hemisphere.
Often called the dark side, it gets as much sunlight as the near side: at new Moon it is almost fully lit, at full Moon it is in night. What it lacks, almost entirely, is the lava plains.
The percentages were calculated from the mare outlines mapped by the LROC team (Nelson et al., 2014) between 65° N and 65° S, as a share of the whole hemisphere’s area.
7 October 1959
Until 1959, apart from the margins that libration reveals, nobody had seen this hemisphere. On 7 October the Soviet probe Luna 3 passed over it and took 29 photographs in 40 minutes, from more than 60,000 km away. They covered about 70% of the far side. The globe is now turned to the view NASA has reconstructed for the probe: from above 12° N, 120° E. NASA NSSDCA · NASA SVS
The pictures were blurred, but they showed enough: on the other side, the seas were almost absent. Mare Moscoviense and the crater Tsiolkovskiy can be made out in them; they are two of the 18 far-side names whose approval year in the gazetteer of the International Astronomical Union (IAU) is 1961. Another is the crater Tsu Chung-Chi, named after Zu Chongzhi, a Chinese mathematician of the fifth century. The yellow dots on the globe mark them.
1970
In August 1970, at its general assembly in Brighton, the IAU adopted about 500 names for far-side craters in one go. A working group had proposed them from photographs sent back by the Lunar Orbiter probes and by Zond 3. The gazetteer as downloaded on 4 October 2026 holds 728 names on this side and 1,295 on the near side, not counting the lettered satellite craters. NASA
One of the 1970 names is Haret, a 30 km crater in the southern hemisphere. Spiru Haret is remembered in Romania as the education minister who built its modern school system around 1900; before that, in 1878, he took a doctorate in Paris with a thesis on the invariability of the major axes of planetary orbits. The gazetteer lists him as an astronomer.
Further north lies Oberth, a 50 km crater approved in 1997. Hermann Oberth, one of the founders of astronautics, was born in 1894 in Sibiu, a Transylvanian town then in Austria-Hungary and now in Romania.
Below the surface
The colours show how thick the Moon’s crust is, worked out from the gravity measurements made in 2012 by NASA’s two GRAIL spacecraft. Dark tones mean thin crust; pale tones, thick crust.
In all four models published by the GRAIL team, the far-side crust is on average 8–9 km thicker than the near-side crust. An explanation often given for the missing seas starts here: thicker crust can keep lava from reaching the surface.
The explanation has a problem, though, and it shows on the same map: the large dark patch in the south of the far side.
The South Pole–Aitken basin
That patch is the largest known impact basin on the Moon: South Pole–Aitken, about 2,500 km across and, on average, some 10 km deep. The colours now show elevation, and the outline drawn is approximate. NASA
Inside the basin the crust is thin: calculated from the four models, its mean within 900 km of the centre is 9–11 km below the near-side mean. Yet mare basalt covers only a few areas of the basin. Crust thickness alone, then, does not explain where the seas are. That is why researchers also look for the explanation further down, in the mantle.
Chang’e 4 and Chang’e 6 both landed inside this basin.
3 January 2019
On 3 January 2019, at 10:26 Beijing time, the Chinese spacecraft Chang’e 4 made a soft landing on the floor of Von Kármán, a crater 186 km across inside the South Pole–Aitken basin. It was the first soft landing on the far side of the Moon. It carried the rover Yutu-2, “Jade Rabbit 2”. CNSA
The centre of Haret crater lies 420 km to the south-east.
Earth is never in the sky here, so a radio signal cannot arrive directly: the Moon itself is in the way. Seven months earlier China had launched the relay satellite Queqiao, “Magpie Bridge”, into a halo orbit around the Earth–Moon L2 point, which lies about 65,000 km beyond the Moon. From there the satellite could see both the landing site and Earth.
In February 2019 the IAU approved five names proposed by China. The landing site is Statio Tianhe: Tianhe is the old Chinese name for the Milky Way. Three small craters around it are called Zhinyu, Hegu and Tianjin, after asterisms on traditional Chinese star charts; the first two belong to the tale of the Weaver Girl and the Cowherd, whom the Milky Way keeps apart. The crater’s central peak became Mons Tai, after Mount Tai in Shandong.
The crater itself has carried since 1970 the name of Theodore von Kármán, the Hungarian-American engineer under whom Qian Xuesen, one of the founders of China’s space programme, took his doctorate at Caltech in 1939. CNSA
June 2024
Five years later Chang’e 6 landed 632 km east of the Chang’e 4 site, in the south of the Apollo basin. The Apollo basin, 524 km across, also lies inside the South Pole–Aitken basin. It was 2 June 2024, 06:23 Beijing time. A second relay, Queqiao-2, launched in March, kept the link from an elongated orbit around the Moon that takes 24 hours to complete. CNSA · CNSA
On 25 June 2024 the capsule reached Earth with 1,935.3 grams of soil and rock: the first samples ever brought back from the far side of the Moon. CNSA
Since August 2024 the site has been called Statio Tianjiang, after the Chinese asterism Tianjiang, whose name means “the celestial river”. IAU
What the samples say
The samples come from one place and tell that place’s story. But it is the very place where the thick-crust explanation fell short.
What can be said so far: the young basalt Chang’e 6 brought back came from a source that was cooler, and poorer in radioactive elements, than the sources of near-side basalts. A 2025 analysis of how the Moon’s gravity responds to tides infers that the near-side mantle is 100–200 K warmer even today (Park et al., Nature, 2025). But the samples come from a single place: whether the whole far side was always cooler is not known.
The cause of the difference between the two sides remains unclear. Some models show that the impact which formed the South Pole–Aitken basin could have set the mantle moving and driven the material rich in radioactive elements towards the near side (N. Zhang et al., 2022). Other hypotheses invoke a slow merger with a second, smaller moon (Jutzi and Asphaug, 2011), or the heat of the newly formed Earth, which would have made crust-forming material settle mostly on the cooler, opposite side (Roy et al., 2014). None is proven.
The globe is yours
Drag the globe to turn it. The buttons below it switch between the photograph, crust thickness and elevation. Each dot is a name in the IAU gazetteer: yellow on the far side, blue on the near side.
The year attached to each name is the one in which the IAU adopted it. The near-side names are much older: the naming system the IAU accepted in 1935 built on names that had been on maps of the Moon since the seventeenth century. NASA
Where Chang’e 4 landed on 3 January 2019.
Where Chang’e 6 landed on 2 June 2024, 632 km from Statio Tianhe.
Spiru Haret (1851–1912), Romanian mathematician and education minister. 420 km from Statio Tianhe.
Hermann Oberth (1894–1989), rocketry pioneer born in Sibiu, in today’s Romania.
Zu Chongzhi, a Chinese mathematician of the fifth century. One of the 18 names approved in 1961.
The “Sea of Muscovy”, one of the few seas on the far side; it can be made out in the Luna 3 photographs.
Konstantin Tsiolkovsky (1857–1935). Its dark, lava-covered floor can be made out in the Luna 3 photographs too.
Where Apollo 11 landed, on the near side.
Where Chang’e 3 landed, on the near side: the “Moon Palace” of Chinese mythology.
Light
The Moon’s phase has nothing to do with which face is seen from Earth. The Sun always lights one half of the Moon; as the Moon circles Earth, more or less of that lit half can be seen from here. At full Moon the far side is in night. At new Moon it is almost fully lit.
Simplified geometry: a circular orbit with no tilt, libration or eclipses. The percentages show how much of each disc is lit. NASA
Measured against the stars, the Moon completes an orbit in about 27.3 days. Meanwhile Earth has moved along its own orbit around the Sun, and the Moon needs about two more days to come back between Earth and the Sun.
24 December 1968 · Apollo 8
The first people to see the far side with their own eyes were Frank Borman, James Lovell and William Anders, on 24 December 1968. The same day Anders photographed Earth coming up over the lunar horizon. NASA
Earth appears to rise in the photograph because Apollo 8 was moving in orbit. For someone standing in the middle of the near side, Earth hangs almost still in the sky. From Von Kármán crater it cannot be seen at all, which is why Chang’e 4 needed a relay.
The photograph is the colour map of the Moon published by NASA’s Scientific Visualization Studio in December 2025, a mosaic of images from the LROC camera on the Lunar Reconnaissance Orbiter, with the polar regions filled in from a less detailed map. NASA describes it as made for appearance, not for measurement. It is evenly lit, and for this page its contrast was slightly raised. It is not a photograph of a single moment.
Elevation comes from the same spacecraft’s LOLA laser altimeter. Crust thickness is model 1 in the archive published by Wieczorek and colleagues; it is a model, built on assumptions about the density and porosity of the crust, which is why the means are given for all four versions: 30–39 km on the near side, 38–47 km on the far side.
Crust thickness inside the basin is the area-weighted mean of each model’s 0.25° grid within 900 km of the centre given by Garrick-Bethell and Zuber (2009): 53° S, 191° E (169° W). The area of the maria is calculated from the outlines mapped by the LROC team between 65° N and 65° S, as a share of the whole hemisphere: 30% of the near side, 2% of the far side, 16% of the whole Moon. Distances between places are great-circle distances from gazetteer coordinates, with a radius of 1,737.4 km. “Far side” here means everything whose centre lies at a longitude more than 90° east or west. Names are counted in the gazetteer as downloaded on 4 October 2026.
The original Luna 3 photograph is in the NASA NSSDCA catalogue; images of the two Chinese landers seen from orbit are on the LROC camera’s site.
Accessed 4 October 2026.