Many people believe that because the geothermal heat flux is ~91 milliwatts/m², this would imply that, without the sun, the Earth’s surface would be ~36 Kelvin. This is calculated the following way: The math is correct, but there are two problems. First, this is for the top-of-the-atmosphere, not for the surface. But I will notContinue reading “How to Underestimate Geothermal”
Category Archives: Astrophysics
Us and Enceladus
Enceladus is the 6th largest moon of Saturn. It has the distinction of being the most reflective object in the solar system. The bond albedo of Enceladus is 0.81. Let’s figure out what the average temperature of Enceladus should be using the standard approach. This is determined by 2 things: Insolation Longwave Radiation from Saturn.Continue reading “Us and Enceladus”
Average Moon Day and Night Temperatures
NASA’s Moon Fact Sheet doesn’t give the diurnal temperature range for the entire moon, just the equator: Strange. They have collected the data. Why didn’t they do the calculations? So I could do it? I went through every 15 degree increment longitude data available here. Day is the center hot spot +/- 90 degrees. NightContinue reading “Average Moon Day and Night Temperatures”
Heat flux in the Sun
The sun is known to emit ~63 Mega Watts per meter squared from its photosphere. But what is the heat flux inside this emissive photosphere? Heat flux formula: q = k*ΔT/L q = k * (6600-4400 Kelvin) / (500,000 meters) What is the thermal conductivity (k) value of hydrogen at these temperatures? [1] This isContinue reading “Heat flux in the Sun”
Zoe's Insights 