The Moon’s Contribution to Nighttime Illuminance in Different Environments

Abstract

The moon’s contribution to illuminance was investigated in order to determine the role it may play in providing a level of illuminance suitable to perform everyday tasks in nighttime outdoor environments. The level of illuminance provided in an area void of artificial lighting was compared to illuminance in an urban environment. Moon phase affected illuminance only in the absence of urban lighting. This effect was lost when controlling for altitude and azimuth, suggesting the moon’s location in the sky has a more significant effect on illuminance than the phase of the moon. These results are discussed in relation to our current understanding and experience of navigating and operating in nighttime environments.