What fraction of the light from the Sun is intercepted and reflected by the Earth? To get an upper bound let us assume the Earth is perfectly reflective, like it would be if it were covered in clouds. To compute it, compare the cross-section of the Earth (the area of a circle with radius REarth) to the area of a sphere centered on the Sun that has a radius equal to the radius of the orbit of the Earth (meaning, take the ratio of those two numbers). You can easily find sizes and distances on the Internet. Please express them in the same units to take a meaningful ratio (meter or kilometers will work best). SHOW YOUR WORK!

What fraction of the light from the Sun is intercepted and reflected by the Earth? To get an upper bound let us assume the Earth is perfectly reflective, like it would be if it were covered in clouds. To compute it, compare the cross-section of the Earth (the area of a circle with radius REarth) to the area of a sphere centered on the Sun that has a radius equal to the radius of the orbit of the Earth (meaning, take the ratio of those two numbers). You can easily find sizes and distances on the Internet. Please express them in the same units to take a meaningful ratio (meter or kilometers will work best). SHOW YOUR WORK!