Why does the moon have phases?

Answer: Sun lights different moon sides

Earth's shadow covers parts — Wrong. Earth's shadow creates lunar eclipses, not phases. Phases occur because we see different portions of the sun-lit half as the moon orbits Earth.

Sun lights different moon sides ✓ — Correct! The moon doesn't produce light—it reflects sunlight. As the moon orbits Earth (~29.5 days), the angle between sun, moon, and Earth changes. We see varying amounts of the lit half: new moon (dark), crescent, first quarter (half), gibbous, full moon (fully lit), and back. Phases result from changing viewing angles!

Atmosphere distorts moonlight — Wrong. Atmosphere doesn't create phases. Phases occur because the moon orbits Earth, changing how much of its sun-lit surface we see.