What is the moon made of?
For thousands of years, people stared up at the moon and wondered what it could possibly be made of. Was it a giant pearl? A ball of ice? Some cultures thought it was made of silver, glowing in the night. Others imagined it was cheese — after all, it had holes like Swiss cheese has holes, didn't it? But the moon turned out to be made of something much stranger than cheese or silver or anything anyone expected.
The moon is made of rock. Not fancy space rock or magical moon crystals — just regular, boring rock. The kind of rock you'd find on Earth, only without any water, without any air, and without anything alive crawling around on it. If you picked up a moon rock and compared it to a rock from a mountain here on Earth, you'd find many of the same minerals: oxygen, silicon, magnesium, iron, calcium. The moon is Earth's cousin, made of similar stuff.
