What characteristics of the Sun’s light affect how the moon appears during a lunar eclipse?

During a lunar eclipse, the key characteristic that affects how the Moon appears is the scattering of sunlight through Earth's atmosphere. When the Earth comes directly between the Sun and the Moon, it casts a shadow on the Moon. However, some sunlight still reaches the Moon after passing through the Earth's atmosphere.

This sunlight is refracted, which bends the light and scatters shorter wavelengths (the blue and violet lights) more than the longer wavelengths (the red and orange lights). As a result, the Moon can take on a reddish hue during a total lunar eclipse, often referred to as a "blood moon." This phenomenon is entirely due to the atmospheric filtering of sunlight, which alters the light that ultimately illuminates the Moon during the eclipse.

Understanding this concept highlights the crucial role of Earth's atmosphere in transforming the appearance of the Moon during such events, which is why the scattering of sunlight is the correct choice in this context.