What is The Dark Side of the Moon: Why do we call it that?First Published: June 8, 2016 Estimated Reading Time: 5 minutes
Over the years, the term “Dark Side of the Moon” has been utilized in many different formats. It’s been part of movie sagas, books, music and popular culture. It is a magnificent section of science and astrology, and it even plays a pretty major role in many different conspiracy theories.
From the housing zone to an alien species to a manmade Dark Side of the Moon that contains a hyper-intelligent and superbly advanced variety of the human race, the Dark Side of the Moon has long been something worth discussing.
The problem is, most people don’t really know why it seems to be called this. Today, we’re going to take a brief look at the term itself, what it actually means, why the name has come around – and what some of the “other” explanations may be.
Far or Dark?
First off, we have to clarify that, most of the time, the Dark Side of the Moon and the Far Side of the Moon are one and the same. For the purposes of this, we’ll be calling it the Dark Side of the Moon.
What Is It?
Well, the Dark Side of the Moon is the side of the moon that always faces away from our beloved planet, Earth. For this reason, it’s “dark” to us as we cannot see what is going on there without actually heading around to find out. Its part of the hemisphere of the Moon, and according to the limited imagery we have seen of the Dark Side of the Moon, it’s loaded with impact craters, lunar maria and is extremely rugged in comparison to its more charming “Light Side”.
The reason for the name Dark Side of the Moon, though, stems from the fact not that it’s entirely darkened, but because we cannot see it.
It’s unknown to us outside of very minimal features and footage, and for this reason what is there is more or less unknown to the majority of us. Indeed, the Dark Side of the Moon gets as much light as the light side – so, for that reason, the moon isn’t magically half-light and half-dark, it’s just that we have only “explored” one half of it…
Of course, conspiracy theorists suggest that it’s like some kind of Death Star, or that it houses an alien race that we’ve never seen of or heard of before.
One thing we do know, though, is that the Dark Side of the Moon plays host to the South Pole-Aitken basin, one of the largest craters that we’ve found in our whole Solar System. Impressive or what?
Given that we can only see around 18% of the moon, and it took us until 1951 to see the remainder of the moon thanks to the Soviet Union’ Luna 3 space probe, the term Dark Side of the Moon seems appropriate.
In 1960, the Soviet Union also created an atlas of the Dark Side of the Moon, and later in the same decade (1968) Apollo 8 sent astronauts to view the Dark Side of the Moon. To this day, they are the first humans to look at this side of the moon, although they never walked on it. As far as we know, nobody has ever done so.
Saying that, as far as we know in some theorists, nobody has ever walked on the moon, light or dark!
Why Is The Dark Side of the Moon Hidden?
Of course, theorists and skeptics wonder why the moon does not rotate as you would expect – it does seem strange, right?
Well, this can be put down to something known as tidal locking. This is apparently caused by tidal forces from Earth slowing down the rotation of the moon, meaning that the same side always faces us. Apparently, we can have as much as 59% of the moon facing us at any one time. The reason we can only see the Far Side, then, comes from the fact that the side we see is getting the sunlight directly reflected from Earth itself.
It’s only during a full moon that we can see the full Far Side of the Moon.
So, why does the Earth slow down the moon? That makes no sense, right?
According to Moon Connection, it’s because over the years the gravitational pull of the Earth has reacted against the moon. The moon used to be much faster, apparently, but our planet has slowed down the moons rotation over a significant period of time. It’s apparently the gravitational force of the moon that causes our planet to have tides, so you can kind of see how this could occur.
The rotational period is apparently around 27.3 days, and this is now locked in as the traditional time period it takes. To ourselves on Earth, though, it takes 29.5 to see the full moon.
Why Does This Matter?
Because, if the moon never spun, we would eventually see both sides. However, since the rotational period and the orbital period is the exact same, we never actually see the other side – we always have the opposite facing us.
The one time we can see the Dark Side of the Moon, though, comes quite rarely. This happens when the moon is a certain distance away from the Earth, and it means that the orbital speed and rotational speed eventually change – the rotational speed overtakes the orbital speed slightly, meaning that over a period of time it allows us to see up to 59% of the moon over a period of time. It might not be the full Dark Side of the Moon, but it’s something at least!
A New Explanation
A really interesting tale comes from the Penn State University, and Jason Wright. One reason why we believe that the Dark Side of the Moon has no maria/seas on it is due to the thickness of the crust on the Dark Side, apparently. They claim that after the supposed impact that made the moon – when something the size of Mars hit Earth and split the moon away from us – that the orbital rotation occurred that more or less locked the moon away from us.
This is because the moon would have been much closer to us than it is today, and this causes a phenomenon that can regularly be seen when a planet orbits too close to a star. Over time, they have separated as much as twenty times the original distance, and this leads to the orbit being much longer than it was in the past. However, the rotational speed has remained the same so this means that whilst the orbit occurs faster, the rotation does not.
VIDEO: The Farside of the Moon – A view from the other side: NASA Video / Lunar
So what does this mean?
The argument from Penn State is the reason we can only see one side is quite simple – as the two massive fragments began to cool over time, given that that the Far Side was seeing heat from two sides, not one, the Dark Side of the Moon would have cooled so much faster. The slower the time it takes to actually cool down, aluminum and calcium begin to “snow out” and this would have happened on the Dark Side of the Moon first.
This means that the thicker crust would have formed, ensuring that when the Far Side of the Moon was hit with asteroids that lava was created to fill the spaces. On the Dark Side of the Moon, this is not possible – the thicker crust prevented lava flow from beginning.
The one thing we can be sure of, though, is that the Dark Side of the Moon is a mystery that is still being unfurled. As always there are theories and counter-theories to battle back against this, but we can finally say that the Dark Side of the Moon has as much genuine light reaching it as the Far Side of the Moon.
The main difference? Our planetary perspective and the way the moon set itself after the collision had occurred.
We don’t know who to believe, but at least now we know that Dark Side of the Moon is more than a brilliant album!