## Dark Part of the Moon & Its Visibility During the Day

Black is a color that results from the absence of light. A dark or black object emits practically no light. It does not emit “black light.”

Flat-Earthers claim the dark part of the moon should appear black during the day. In reality, they fail to understand that black is caused by the lack of light, not by the emission of “black light.”

## Moon Phase and Earth Phase Relation

The phase of the moon seen from Earth is the opposite of the phase of Earth seen from the moon at the same time. If we see a crescent moon from Earth, then someone on the moon at the same time will see a gibbous Earth, and vice versa.

Flat-Earthers noticed the phase of the moon during an Apollo mission was different from the phase of Earth in photos from the mission. Then they used it to discredit the Moon landing, wrongly assuming both phases should be identical. In reality, the two phases are opposite each other, and they will check out.

## Illuminated Fraction of a Full Moon

The orbit of the Moon is tilted 5.145° to Earth’s orbit around the Sun. As a result, a lunar eclipse does not occur every month, and a full moon is never 100% illuminated.

Flat-Earthers claim a full moon should not be possible due to the tilt of its orbit, incorrectly assuming a full moon means 100% illumination. In reality, a maximum full moon is at least 99.8% illuminated, and we cannot tell a 98% illuminated moon from a 100% illuminated one. We call it a full moon, even if it is never 100% illuminated.

## Flat Earth Dome Model

The “Flat Earth Dome Model” (walter.bislins.ch/FED) is an app created by a fellow flat Earth debunker, Walter Bislin. The app attempts to map observed reality to the flat Earth model. Lines in the app portray how light rays must have traveled if Earth were flat. They demonstrate that light must bend in a physically impossible way if Earth were flat, disproving a flat Earth.

Videos of the app are circulating in flat-Earth communities, and flat-Earthers fail to understand what the app is showing. They incorrectly assume the app “proves” a flat Earth when in reality, it thoroughly disproves the flat Earth model.

## The Appearance of the Moon on the Different Locations on Earth

Everyone on Earth observes the same face and phase of the Moon at the same time, provided the Moon is visible from the location of the observer. This fact is contrary to what the flat Earth model requires. It rules out the possibility of a flat-Earth and that the Moon is a sphere hovering a few thousand miles above Earth’s surface.

## Lunar Phase: Earth’s Shadow has Nothing to do with It

It can be surprising that many people believe that the lunar phase is caused by the Earth casting its shadow on the surface of the Moon. Flat-Earthers are no exception. But they take it one step further and use the misconception do “disprove” the fact that Earth is a sphere. They are wrong. The lunar phase is the shape of the sunlit part of the Moon seen from the observer.

On the other hand, the phenomenon where the Earth casting its shadow on the surface of the Moon is called the lunar eclipse. Moon phase occurs all the time and undergoes a monthly cycle, while a lunar eclipse happens only a couple times in a year.

## Lunar Craters

At any time, the Sun illuminates one half of the Moon and the other half dark. The phase of the Moon is the shape of the sunlit portion of the Moon as viewed by observers on Earth.

The phase of the Moon can never be adequately explained using the flat Earth model. To deal with this inconsistency in their theory, some perpetrators of flat Earth invented an ‘explanation’ that the phase of the Moon is not caused by sunlight. They are wrong. We can observe the Moon very carefully using telescopes of high-zoom cameras, and it will be evident how the lunar craters are lit. And this can only happen if the Moon is sunlit.

## Phases and Side of the Moon

In the real world, the Moon is spherical. It doesn’t emit its own light; it gets its light from the Sun. The Moon is tidally locked, causing one side of it to be permanently turned towards the Earth. The lunar phase occurs because of the change in the position of  Sun-Earth-Moon with respect to each other.

Any flat-Earth model fails to explain many Moon-related phenomena. Flat-Earthers who insist on defending their misguided flat-Earth concept at all costs are forced to invent many “explanations” on how Moon-related events might happen on a flat-Earth.

Simple observation tells us that we always see the same side of the Moon, but the phase changes in a month-long cycle. These facts rule out the majority of the “explanations” invented out of thin air by flat-Earthers, including the “Moon emits its own light”, “half-sphere Moon” and the “transparent Moon” explanations.

## The Moon in Daytime and the ‘Transparent Moon’ Misconception

Earth’s atmosphere scatters sunlight in every direction. Bluish colors are scattered stronger than reddish tones. As a result, the sky is glowing in bright blue during the day. The phenomenon is called the Rayleigh scattering.

Sometimes the Moon is visible during the day. The bright part of the Moon is bright because it is lit by the sunlight. On the other hand, its dark part does not receive sunlight, and thus barely emit any light. Because of these reasons, the dark part of the Moon is dominated by the blue color of the sky.