0:02:50 > 0:02:57.
0:03:04 > 0:03:06Welcome to Science Fiction,
0:03:06 > 0:03:09the show which explores the outer limits of the cosmos.
0:03:09 > 0:03:11So that you don't have to - hm!
0:03:11 > 0:03:13Knowles to BUD-E, do you read me?
0:03:13 > 0:03:17Receiving you loud and clear, Doc. Today's question comes from...
0:03:21 > 0:03:24Well, Liam, the dark side of the moon is a mysterious place
0:03:24 > 0:03:27full of monsters and vampires, and dinosaurs...
0:03:27 > 0:03:29Professor, don't be ridiculous!
0:03:29 > 0:03:33The moon does not give off light, it reflects light from the sun.
0:03:33 > 0:03:34A bit like this - look.
0:03:34 > 0:03:36Ha-ha-ha!
0:03:36 > 0:03:39As the moon orbits the Earth it also rotates on its own axis.
0:03:39 > 0:03:42Which means that the moon is flying around the Earth
0:03:42 > 0:03:44and spinning away mad at the same time.
0:03:44 > 0:03:48It takes the moon roughly 29 and a half days to orbit the Earth.
0:03:48 > 0:03:50That's where we get our months from. Fact.
0:03:50 > 0:03:53And this is also the exact amount of time it takes
0:03:53 > 0:03:55to complete one rotation on its axis.
0:03:55 > 0:03:59So, you mean, like, by the time it's travelled around the Earth
0:03:59 > 0:04:01- it'll have spun around once as well?- Exactly!
0:04:01 > 0:04:03And because of this unique relationship
0:04:03 > 0:04:06we always see the same side of the Moon here on earth.
0:04:06 > 0:04:07That's brilliant.
0:04:07 > 0:04:09Oh, but come here though, Dr Knowles,
0:04:09 > 0:04:12is the other side still all dark and full of monsters, so?
0:04:12 > 0:04:13No, Professor,
0:04:13 > 0:04:17the entire moon receives roughly the same amount of light all over.
0:04:17 > 0:04:20So, if we were to travel to the far side of the moon
0:04:20 > 0:04:23we'd see it lit up in exactly the same way.
0:04:23 > 0:04:26Ha, that looks like a brilliant craic, I want to go there!
0:04:26 > 0:04:28So, now you know how it works.
0:04:28 > 0:04:30That whole myth about the dark side of the moon...
0:04:30 > 0:04:32Sure, that's just a load of old science fiction!
0:04:37 > 0:04:40Here, look at me, Dr Knowles, I learnt how to do the moonwalk.