The sun radiate a power of 3.9 x 10 ^ 26 watt in space . The earth orbits around the sun of radius of 1.5 x 10 ^11 m . What power strike at 1 m ^2 area on the earth ? The rotation aaxis of the earth is tilted by 27 degree relative to the plane of orbit. What is the intensity of sun light on the noon time at the equation on the winter days ?