Which factor significantly affects the climate of a planet?

The climate of a planet is significantly influenced by its distance from the Sun because this determines the amount of solar energy the planet receives, which is a primary driver of temperature and weather patterns. A planet that is closer to the Sun will generally be warmer, while a planet that is further away will receive less sunlight and tend to be cooler. This distance also affects the types of atmospheric conditions and the potential for liquid water, both of which are crucial for supporting life and various climate systems.

While factors such as the color of the planet's surface, the planet's rotation speed, and the presence of moons do have some impact on climate, they are secondary in comparison to the effect of distance from the Sun. Surface color can influence heat absorption, rotation speed impacts day length and weather patterns, and moons can affect tides and stability of the climate over long periods. However, none of these factors can alter the fundamental solar energy input that is determined primarily by a planet’s proximity to the Sun.