The greenhouse effect is significant not only on Earth but also on Venus and Mars. The following table summarizes the following basic observations: 

(A) Using Stefan's equation and the principle of loss of energy flux density as a function of distance from the Sun (T=5800^oK), calculate the irradiance I at the top of the atmosphere of each of the three planets.

(B) The effective energy reaching the planetary surface should be the amount calculated in (a) divided by 4 (because only the planetary disk, the 2D surface ΠR_planet²) faces the Sun at any given time.  Use Stefan's equation to calculate the energy that will be emitted by each of the three planets given the solar irradiances calculated in (a), and calculate their effective surface temperatures. Why don't the results agree with Column 2 in the above table? Explain a likely reason for the discrepancies, and compare the discrepancies among the planets.