Here's why:
* The Moon's Phases: The moon itself doesn't produce light; it reflects sunlight. As the moon orbits the Earth, the amount of sunlight we see reflected changes, creating the different phases (new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, waning crescent).
* Earth's Satellites: Satellites are artificial objects orbiting Earth. They don't exhibit phases like the moon because they don't reflect sunlight in a way that creates these visible changes.
Let me know if you have more questions about the moon's phases or Earth's satellites!