25 September 2014
The Short Answer (TSA)
Maybe one of the strangest facts about our moon is its rotation. For example, the Earth orbits around the Sun about every 365 days – a year. On the other hand, the Earth rotates on its axis every 24 hours – a day. But our Moon takes about 27 days to orbit once around the earth. How long does it take to Moon to rotate on its axis? Again, about 27 days. The Moon’s “year” and the Moon’s “day” are exactly the same. A remarkable coincidence.
But this remarkable coincidence produces a remarkable effect. If you were on the Moon, you’d experience one slow day and one slow night every 27 earth-days. But if you watch the Moon from the Earth, the Moon doesn’t seem to rotate at all. Since it’s always been that way, most of us don’t notice that, when you watch from the Earth, you always see the same side of the Moon. Only one side. Viewed from the Earth, you never see “the far side of the Moon.”
Over the centuries, the far side of the Moon developed quite an air of mystery. You could imagine anything to be there.
In the early 1950’s, George Adamski, the owner of a café near Mt. Palomar Observatory reported receiving visits from outer space aliens. Looking and dressing like us, the aliens would stop by his café to chat. Adamski also reported taking several trips into outer space in the alien’s saucer. He closely observed the far side of the Moon and reported that it supported a substantial civilization and population. He even brought back “moon potatoes,” which reportedly looked like rocks.
However, Adamski’s claims came into substantial question, in 1959, when the Soviet Luna 3 space probe circled the Moon taking photographs. The resulting atlas, published in 1960, included precise details of the topography of the (no longer so) mysterious far side of the moon. In 1968, the Apollo 8 astronauts became the first humans to view the far side of the Moon. (No signs of life, civilization, or potato farms were to be seen.)
The far side of the Moon used to be called “The Dark Side of the Moon.” This phrase was accurate enough if the speaker meant to refer to the side of the Moon that was “dark” or unknown to viewers on Earth. But the problem with the name was that the “dark” side of the moon isn’t always dark. During half of the 27 earth days it takes the Moon to complete one of its own days, at least part if the so-called dark side is sunlit.
So, the side of the Moon we can never see from the Earth is, now, called “the far side of the Moon.” The phrase “dark side of the moon” means the half of the Moon that is actually dark at any particular moment.
So, at the “New Moon” phase, the Moon can’t be seen from the Earth. So, with the New Moon, “the dark side of the moon” is actually the side that is facing us on Earth. At the Full Moon phase, the entire visible face of the Moon is sunlit. So, with the Full Moon, “the dark side of the moon” is completely on the other side of the moon. On the night of the full moon, the dark side of the moon and the far side of the moon are exactly the same thing.
Lots of Moons & Music 
