What is the general pattern of the relationship between the distances of the planets from the Sun and their temperature

Question

What is the general pattern of the relationship between the distances of the planets from the Sun and their temperature?

 

Answer 1

Temperature is a measure of the average heat (aka kinetic) energy of the particles within a substance. The amount of heat radiation (H) from the sun varies indirectly as the square of the planet's distance from the sun:

H ∝ 1/r²

where H is heat and r is the planet's distance from the sun. So, as a first approximation, the planet's temperature also fall off as the inverse square of distance:

T ∝ 1/r²

So if planet B is twice as far from the sun as planet A, it will receive 1/2² = 1/4 as much heat energy and will be only 1/4 as warm. Other factors, such as internal planetary heat and greenhouse gasses in the atmosphere can also impact a planet's temperature.  Venus, for instance is almost twice as far from the sun as Mercury but has a higher surface temperature due to a runaway Greenhouse Effect in its atmosphere.