How hard would it be for an alien astronomer to detect the light from planets in our solar system compared to the light from the Sun itself?

Calculate the fraction of the total emitted sunlight that reaches Earth. (Imagine a sphere around the Sun the size of Earth’s orbit (area = 4 πa ² ), then calculate the fraction of that area taken up by the disk of Earth (area = π r ² planet). Earth's reflectivity is 29%).