We get a LOT of questions about the moon. We're going to try to answer some of them here, so get ready for takeoff!
First, some fast facts about our moon. It's about one quarter the size of Earth and it orbits (travels around) us. While Earth only has one moon, some planets have many more. For example, Jupiter has 79 known moons — with more likely to be discovered!
Our moon is pretty much a big rock, and does not produce its own light. It looks white because of the sunlight that reflects off it. From here, the moon seems about the same size as the sun. But the sun is actually about 400 times larger and 400 times further away!
A blue moon is when we get two full moons in a single calendar month. This rarely happens. That's why when something happens very rarely, people say it happens "once in a blue moon."
Another question we received is about what causes a blood moon. A blood moon occurs during a total lunar eclipse, when the moon appears to be a coppery red colour. This happens because Earth is between the moon and the sun, blocking the sunlight. The only light that reaches the moon's surface is from the edges of the Earth's atmosphere. The air molecules scatter the rest of the light, and what's left reflects onto the moon's surface with a red glow. The moon also looks reddish sometimes because of dust or smoke.
There is no permanent "dark side" or "bright side" of the moon, but there is a near side and a far side. Just like how there's day and night on Earth, both sides of the moon get equal amounts of sunlight over time. The moon rotates at the same speed as it orbits Earth, so from our position we are always seeing its same side.
This means that if you're talking about the dark side, you could be referring to the side of the moon we can't see from Earth... or the side where the sun isn't hitting it... or having an entirely different conversation about comic books or Star Wars!