Final answer:
Distance from the Sun has an inverse relation to average surface temperature: the farther away, the cooler the surface temperature. This is due to the inverse square law of radiation. Mercury, being closest to the Sun, is much hotter than distant Pluto.
Step-by-step explanation:
The relationship between distance from the Sun and average surface temperature of a celestial body, such as a planet or moon, is an inverse one, governed by the inverse square law of radiation. As the distance from the Sun increases, the intensity of sunlight and therefore the energy received decreases with the square of the distance, leading to lower surface temperatures. For instance, Mercury, being the closest planet to the Sun, has very high surface temperatures, ranging between 280-430 °C, while distant Pluto experiences extremely cold temperatures around -220 °C.
On a stellar level, a star's surface temperature can indicate its luminosity and radius, essential characteristics that define its energy output. Stars emit radiation peaking at certain wavelengths depending on their temperature; for example, the Sun has a surface temperature of approximately 5800 K. This temperature influences the amount and type of radiation that planets in its vicinity receive.
The relationship between surface temperature and distance from the Sun is critical in understanding planetary climates and the potential for liquid water, which during Earth's Hadean eon, existed despite the Sun's radiant energy being 25% less intense than today. Such understanding extends to learning about the evolution of planetary atmospheres and the conditions that might make a planet habitable.