When we’re little, we have some really interesting ideas about the moon. It follows us at night. It gets smaller and bigger, and sometimes it disappears. Maybe it’s made of cheese, or there’s a man on the moon. There are the obvious things we can debunk right away—the moon’s not following you around, it is an optical illusion because of its distance relative to you when you are in motion; the moon’s not made of cheese; and although man has been on the moon, it only looks like it has a face because of the craters on its surface.
But what else do we know?
Well, here’s a cool fact: you’re always looking at the same hemisphere of the moon. The moon rotates (spins) at the same rate that it revolves (travels in a loop) around the earth. The other side of the moon isn’t actually “dark,” it is just facing away from us.
So, if we’re always seeing the same side of the moon, what makes it change shape? The amount of light hitting the moon at any given time. This is what causes the moon to slowly disappear (waning) and reappear (waxing) in the sky. It takes about 27 days for the moon to complete its path, but since the earth is moving as well, to us it looks like 29 days.
OK, now we’ve told you how the moon moves and appears to change shape. But how did we even get the moon? Well, the theory most scientists agree on is that something roughly the size of Mars collided with Earth about 4.5 billion years ago. The debris that resulted formed our moon. It has a partially molten core consisting of mostly iron, and then what’s called a mantle between that and the surface—probably made up of things like olivine and pyroxene. Then there is the crust, which is made up of things like magnesium, calcium, iron, and silicon. That means there really is no cheese on the moon.
Wonder what life would be like on the moon?
Unfortunately, it would be pretty hard to live there. For starters, the atmosphere is a lot thinner than ours. That creates two immediate problems: you would not be able to breathe, nor would you be protected from the sun’s radiation. Assuming you had a space suit to help you with those things, it would also have to regulate your body temperature: where the sun’s full light shines on the moon, temperatures reach about 260˚F, and can reach -280˚F in darkness.
But even the best space suit wouldn’t help you with the next hazard: the thin atmosphere also provides no protection from things like asteroids and comets (unlike Earth, where many of these things burn up before ever coming close to us). That’s why the moon has so many craters, and the surface is littered with rocks and boulders. There’s also no water to speak of, so you’d have to bring your own. Without water, a food supply would also be difficult to maintain, so that’s something else you’d have to bring with you.
Your next challenge would be gravity. The forces holding you down are much weaker, only about 1/6th of the gravity of Earth. Meaning, you would weigh six times less on the moon. That’s why, despite their heavy equipment, astronauts on the moon look like they’re practically floating as they walk. It could make doing even simple activities much more difficult. It something was too light, it would simply float away. With the right technology, life could be possible for us on the Moon, but it would bring with it significant challenges,
Now you know a few more facts about the moon. Think about them the next time you look up into the sky at night!