1. The problem statement, all variables and given/known data How much energy is radiated from the earth to space? AE = Area of Earth εE = Emissivity of Earth TE = Temperature of Earth Tsp = Temperature of Space Tsp = 2.7 K (off of NASA web page) 2. Relevant equations P = AE εE σ (TE4 - Tsp4) 3. The attempt at a solution Isn't the relevant equation the answer to the question? The average temperature of the earth is "all over the place" depending on which web site, college, governmental agency or science club you look at. If I picked an temperature of the earth, then I could calc. the power correct?