行星溫度同和太陽的距離

1. 行星距離太陽愈遠, 所接收到的 energy 愈少.
2. 只要行星不是絕對零度, 便會 radiate energy, 溫度愈高, radiate 得愈快, 在較低的溫度便會達到平衡 (接收到的 energy 等於 radiate 走的 energy 的溫度)

radiation傳播, 係全四方八面 , 當愈遠 , 所到達的紅外幅射愈低

因为距離加大，範圍也加大，咁樣個平均溫度就會越低。

Don't forget that the propagation of radiation follows the inverse square law. The farther away from the sun, the lower is the intensity of radiation.

Apart from this, whether there is a gaseous atmosphere on the planet to trap the incident radiation also plays an important factor.