Sunlight at 0.64 um reflected by the Earth is absorbed by a nadir viewing satellite sensor at an altitude of 800 km. The sensor has a circular detector with a radius of 1 mm and a bandwidth of 0.1 um centered at 0.64 um. The scene viewed by the sensor is a circle with radius 1 km. If the scene being viewed has an albedo of 0.25, reflects sunlight isotropically, and the solar zenith angle is 60", what is the power (W) of reflected sunlight absorbed by the sensor's detector? [a total of 5 points]