The moon makes a complete orbit once every 27.3 days.

Early in its history, the moon’s rotation slow­ed and became tidally locked in its orientation with Earth. The energy it used to use to rotate relative to Earth quick­ly dissipated as heat, chan­ging its structure.

Eventually its orbit aligned with its rotation, bringing us to the pre­sent where the same part of its surface is always seen from Earth. This means that we always see the same ‘face’ of the moon.

The far side of the moon is sometimes called the ‘dark side’ of the moon; however, in reality, this part of the moon is as bright as the near side. This does not mean that the far side has the same shape; in fact, it is roughly two kilometres higher in altitude relative to the near side.

This shift occurred during the moon’s early period when the moon’s orbit was still forming.

Another distinction between the two sides of the moon can be found in the positions of its maria, or ‘seas’. The large basins on the moon’s surface were formed by ancient volcanic eruptions.

On the near side 31 per cent of the surface is covered by these areas as compared with two per cent on the far side. This is thought to be due to the higher presence of heat-producing elements that would have risen to the crust.

So what is the dark side of moon? Well, as the moon orbits around the Earth, the sun shines on different areas of its surface. This gives rise to the phases of the moon.

An example of an extreme of this is during a solar eclipse where the far side of the moon is com­pletely lit by the sun, while for regular periods part of both sides are lit, giving the strange shapes we have become accustomed to.

So the dark side of the moon is actually moving around the moon all the time!

Find more myths debunked at http://www.iflscience.com .

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