Explain the two different ways of finding the surface temperature of the planet?

The two most common methods which are used to find the temperatures of the planets are discussed below:
Wien’s Displacement Law: We know that planets emit radiations. Now, our work is to study the spectrum of the emitted radiations and their wavelength with respect to their maximum intensities.

So, according to the Wien’s Law, the equation through which the temperature of the planet can be found is shown below:
T = b
B is the Wien’s constant having value 2.884 X 10^-3 mK.
After finding the temperatures of some of the planets it is said that the temperature of the planet Pluto is minimum and of mercury is maximum. The temperature of the planet Pluto is nearly -240^oC and that of the mercury is 340^oC. The above temperatures were calculated during day time.

Stefan’s Fourth power Law: We know that all planets emit heat radiations. Now for finding the temperature we want the value of E. E is the amount of heat energy emitted per unit area per second. According to Stefan’s equation:
E = T⁴
is the Stefan’s constant having value of 5.67 X 10^-8 Js^-1 m^-2K^-4.