# Viewing the Moon

The average intensity of the full moon is $2.92 \times {10}^{-4} W/{m}^{2}$. Approximately how many photons enter the eye per second whenever we look at the full moon on a clear night?

Assumptions

1) The area of the pupil is $3 \times {10}^{-5} {m}^{2}$

2) The wavelength of the moonlight is 550 nanometers

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