* Planets are not luminous: They don't produce their own light.
* Sunlight: The sun is a massive star that emits a vast amount of light and heat.
* Reflection: When sunlight hits a planet's surface, some of it gets absorbed, and some of it gets reflected back into space.
* Our view: The reflected sunlight is what we see from Earth, allowing us to observe planets in the night sky.
The amount of light reflected depends on the planet's composition, surface features, and atmosphere. For example, Venus is very bright because its thick atmosphere reflects a lot of sunlight. Mars, with its reddish dust, reflects less light.
