LOL... I wish for one second I wasn't a Biologist... and I paid more attention in my Astronomy class.. but just ask any Astronomer... he/she will gladly explain to you... there is no such thing as "dark side" of the moon... we know everything that's on the moon.. planets rotate, and some sides get light at this time and then on at another time they don't.. and there are some parts, that simply get low levels of light... but whatever... physics isn't my strength, so I can't explain it well... just ask anybody who majors in this shit.