While one side of the Moon permanently faces towards Earth<\/a> and one permanently faces away, both sides receive pretty much equal quantities of sunlight over the course of any given year.<\/p> There is no dark side of the Moon because there is no side of the Moon permanently shielded from sunlight.<\/p> But \u201cdark\u201d has other meanings.<\/p> One of these, per the Merriam-Webster dictionary, is \u201cnot known or explored because of remoteness\u201d \u2013 which is one reason why the Moon\u2019s far side is often, perhaps misleadingly, called the dark side.<\/p> In more recent times, another sense of the word \u201cdark\u201d has emerged.<\/p> People who suddenly aren\u2019t available through the normal communications channels can be said to have \u201cgone dark\u201d.<\/p> This meaning, too, can be fairly applied to the lunar far side, because the Moon blocks radio signals sent to or from any craft that\u2019s orbiting there.<\/p> Perhaps in some sense, you can talk about the ‘dark side’ of the Moon.<\/p> All the same, astronomers\u00a0\u2013 to avoid confusion \u2013 talk about the far side of the Moon<\/a>, rather than the dark side.<\/p> The reason the Moon has a far side at all, is due to a gravitational phenomenon called ‘tidal locking’.<\/p> Gravity keeps the Moon at such a distance from Earth that it takes 28 days to orbit our planet.<\/p> But 28 days is also how long it takes the Moon to rotate once on its axis, which is why one side of the Moon is always facing Earth and one side is always facing away.<\/p> This, by the way, is actually quite a common phenomenon.<\/p> Within our own Solar System, Mercury is tidally locked to the Sun, while other tidally locked satellites include, among others, Mars\u2019s moons Phobos and Deimos<\/a>, Neptune\u2019s moons Proteus and Triton, Pluto\u2019s moon Charon, and too many of Jupiter, Saturn and Uranus\u2019s moons to list here.<\/p> Back to our own Moon, though, and it should be pointed out that the tidal locking described above is not a perfect system.<\/p> Slight variations in the Earth-Moon distance cause a phenomenon called lunar libration<\/a>, an apparent oscillation of the Moon as seen from Earth.<\/p> And thanks to libration, some far side regions that lie very close to the terminator<\/a> (the putative dividing line between the near and far sides) are occasionally visible from Earth.<\/p> These include Mare Orientale<\/a> and Crater Einstein<\/a>.<\/p> Such regions make up around 18% of the lunar far side\u2019s surface area.<\/p> The other 82% is forever out of sight \u2013 or at least, it was until the first lunar orbiting missions, both Russian and American, in the late 50s and early 60s. <\/p> Since then, the whole of the far side has been photographed and mapped by orbiting spacecraft.<\/p> More recently two missions have actually touched down there: China\u2019s Chang-e 4 in 2019 and Chang-e 6<\/a> in 2024, with NASA\u2019s Artemis III due to follow in 2026.<\/p> Scientists are interested in the far side partly because its topography is quite different from that of the near side, with lots more impact craters and basins, and far fewer smooth, flat mare<\/a> regions.<\/p> And partly because there is growing interest in the idea of eventually constructing a radio telescope there.<\/p> That\u2019s because such a telescope would be facing out into space, and be shielded by the Moon\u2019s sheer bulk from any signal interference originating from Earth.<\/p> We\u2019ll see if that ever happens\u2026 but in the meantime, here\u2019s a fun fact to end on.<\/p> As we\u2019ve already said, both sides of the Moon receive a roughly equal amount of direct sunshine per year.<\/p> But like all the best stories, that seemingly simply tale contains a couple of twists.<\/p> Firstly, the near side of the Moon, unlike the far side, is also exposed to sunlight that\u2019s been reflected off Earth, just as here on Earth we get moonlight that\u2019s really sunlight reflected off the Moon.<\/p> In fact, a \u2018full Earth\u2019, as seen from the Moon, is 34x brighter than a Full Moon seen from Earth.<\/p> But there\u2019s another factor to take into account, which is that the near side of the Moon is regularly occulted, at least in part, by Earth\u2019s shadow.<\/p>![\"View](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2020\/08\/far-side-moon-nasa-galileo-1024x1021.jpg?fit=800%2C798\")
Far side of the Moon explained<\/strong><\/h2>
Libration<\/strong><\/h2>
![\"Thanks](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2020\/09\/Lunar-libration-6de3047.jpg\")
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Why the far side of the Moon is important<\/strong><\/h2>
![\"A](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2023\/03\/Apollo-11-Earthrise-85e3c78.jpg\")