Directly from Luna:
* Lunar: Relating to the moon.
* Lunatic: Formerly thought to be influenced by the moon, now meaning insane.
From related Latin words:
* Lunation: A complete cycle of the moon's phases (approximately 29.5 days).
* Selene: Greek goddess of the moon, from which we get "selenite" (a type of crystal), "selenography" (the study of the moon's surface), and "selenology" (the study of the moon).
Other words with "Luna" that are not directly related:
* Luna moth: A large, beautiful moth with a crescent-shaped marking on its wings.
* Lunaria: A genus of flowering plants with seed pods resembling the moon.
Let me know if you'd like more examples!