Planets don't actually shine on their own. They reflect sunlight, which is why we see them in the sky. Here's a breakdown:

* Planets are not stars: Stars produce their own light through nuclear fusion. Planets are much smaller and don't have the mass or internal processes to create their own light.

* Sunlight reflection: Planets are illuminated by the Sun's light. They act like mirrors, reflecting a portion of the sunlight that falls on them.

* Brightness and visibility: The amount of sunlight a planet reflects depends on its size, reflectivity (called albedo), and distance from the Sun. Larger, more reflective planets closer to the Sun appear brighter in our sky.

Think of it like this: a mirror doesn't produce light, but it allows you to see the light from a source (like a lamp) by reflecting it. Planets work in a similar way!