No, planets and moons do not emit their own light. They are illuminated by the light of the Sun. The only object in our solar system that emits its own light is the Sun.

Planets and their moons are visible from Earth because they reflect the light from the Sun. The amount of light that an object reflects depends on its surface properties, such as its color, texture, and composition. Objects with light-colored surfaces reflect more light than those with dark-colored surfaces. Objects that are smooth or shiny reflect more light than those that are rough or dull.

Planets and moons can also appear brighter due to the effects of the atmosphere. For example, the Earth's atmosphere scatters sunlight, which creates the blue sky and makes the Sun appear brighter during the day. The atmospheres of other planets and moons can also cause them to appear brighter. For example, the presence of water vapor in the atmosphere of Venus makes it appear brighter than it would otherwise be.

In conclusion, planets and moons do not emit light, but they can appear bright because of the sunlight they reflect. The reflection of sunlight depends on the surface properties of the object and the effects of the atmosphere.