10 things you didn’t know about the moon

For a long time, we didn’t know much of anything about the moon. That’s part of the reason why humans have made up so many stories — maybe you’ve heard it’s made of cheese? — about the globe that lights up the sky most nights.

Although it’s not a giant hunk of floating Swiss, our moon is a fascinating part of our solar system. Here are a few facts about it from NASA, Britannica Kids, National Geographic and the National Oceanic and Atmospheric Administration.

1. The moon is about one-fourth the size of Earth, and is made almost completely out of rock.

2. The range of temperatures on the surface of the moon is much greater than the range we experience on Earth. At its hottest, when the sun’s rays hit its surface, the moon’s average temperature is 225 degrees Fahrenheit. At night, it drops to -243 degrees Fahrenheit.

3. From Earth, we always see the same side of the moon. That’s because it takes about 27 days for the moon to orbit the Earth and about 27 days for the moon to compete one spinning rotation.

4. The side of the moon that never faces the Earth is known as “the far side” or “the dark side” of the moon. No human had ever seen the far side of the moon until the Soviet Luna 3 took a photo of it in 1960.

5. The moon doesn’t produce its own light. Instead, the moon reflects light from the sun, and this reflection makes it visible to us on Earth. How much of the moon we can see depends on the angle the moon makes with the sun.

6. Neil Armstrong and Buzz Aldrin were the first people to walk on the moon. Since that event in 1969, 10 other astronauts visited the moon but no other human has been there since 1972.

7. We don’t know exactly how the moon formed, but one popular theory holds it is the leftover bits of a giant rock, named Theia, that crashed into Earth 4.5 billion years ago.

8. The moon has its own gravitational pull, like Earth, but it is much weaker. This means you would weigh much less on the moon than you do on Earth — much less. Someone who weighs 100 pounds would only be 16.6 pounds on the moon!

9. The moon causes high and low tides in the Earth’s oceans. The moon’s gravitational pull creates tidal force, and this force makes the Earth’s water “bulge” — creating a high tide — on the side closest to the moon and the side farthest away.

10. Other planets in our solar system have moons, too. Every planet but Mercury and Venus have at least one moon, and both Saturn and Jupiter have dozens in their skies.