Learn Dutch: De maan draait rond de aarde. - The moon revolves around the Earth.

You would place niet directly after the verb: De maan draait niet rond de aarde. As you are learning in this lesson, niet usually comes before prepositional phrases (parts of the sentence starting with location words like rond, in, or naar).

Could I use om instead of rond in this sentence?

Yes, you absolutely can! De maan draait om de aarde is completely correct and very common. Both rond and om translate to "around." Rond just puts a tiny bit more emphasis on the physical, circular shape of the path.

Why aren't maan and aarde capitalized like they often are in English?

In Dutch, the words for earth (aarde), sun (zon), and moon (maan) are almost always written with lowercase letters in everyday language. They are only capitalized in strict astronomical texts when listed alongside other specific planets, like Mars or Venus.

Does draaien only mean "to revolve" in a scientific sense?

Not at all. Draaien is the standard, everyday Dutch verb for "to turn." You use it when you turn a steering wheel, turn around to look behind you, or even when a machine is running (for example, de wasmachine draait means "the washing machine is running").