Planck's Law:

$E(T,)=\frac{C_1}{{}^5(e^{\frac{C_2}{T}}-1)}$

where $C_1$ and $C_2$ are constants and $T$ is in Kelvin.

Constants: The speed of light $(c)$ is $3{10}^8$ meters per second. The solar sphere of our Solar System has a radius of $6\mathrm{.}96{10}^8$ meters. The distance from the center of our sun to the Earth is approximately $1\mathrm{.}5{10}^{11}$ meters. The surface irradiance of the Sun is $6\mathrm{.}32{10}^{7}W{m}^{-2}.$ The Earth's solar constant can be approximated as $1370W{m}^{-2}.$ You can assume unless otherwise noted that the Earth system refiects $30\%$ of incident solar radiation. One metric ton is equal to $1,000,000$ grams.