What do we call the round object that orbits Earth and lights up the night?

The round, glowing object that circles Earth and lights up our night sky is the Moon, Earth's closest neighbor in space.

The Sun is a giant star, not something that orbits Earth, and a comet is an icy space rock that only passes by occasionally — neither one is Earth's steady nighttime companion.

The Moon doesn't actually make its own light — it shines because it reflects sunlight bouncing off its surface, the same way a mirror reflects light in a room.