* Solar Radiation: The sun emits energy as light and heat. This energy travels outwards in all directions, and the closer a planet is to the sun, the more of this energy it receives.
* Inverse Square Law: The intensity of solar radiation decreases with the square of the distance from the sun. This means that if you double the distance from the sun, the amount of solar energy received drops to one-fourth.
* Other Factors: While distance is the primary factor, other things also influence planetary temperature:
* Atmosphere: Planets with thick atmospheres can trap heat (like Venus), making them hotter than they would be based on distance alone. Conversely, planets with thin atmospheres (like Mars) lose heat more easily.
* Albedo: The reflectivity of a planet's surface affects how much sunlight is absorbed. Bright, icy surfaces reflect more sunlight and stay cooler than darker, rocky surfaces.
* Internal Heat: Planets can generate heat from their interiors, like volcanic activity, which can contribute to their overall temperature.
In summary: The distance from the sun is the most important factor determining a planet's temperature. The farther a planet is from the sun, the less solar radiation it receives, resulting in a colder temperature.
