Visual albedo is the measure of the reflection of sunlight out of the total solar radiation received by an astronomical body, taking into account only the visible light. The visual albedo of the Earth is 0.37, and the Moon’s is 0.12.
The Moon appears dark if the Earth also appears in the same photograph. Flat Earthers use the fact to dismiss such photos as fake. In reality, the Moon’s brightness in a photo is just a matter of choosing the correct camera exposure. But if Earth is also present, increasing the exposure will make the Earth appear too bright.
Because the visual albedo of the Moon is less than that of the Earth, then if both the Earth and the Moon appear in the same picture, the Moon will appear darker than the Earth, as long as the photo was taken in a single exposure, not a composite of two different exposures.
We can raise the exposure by two stops to make Moon brighter, just like any photos of the Moon we used to see. However, if the Earth is in the same photo, it will become too bright.
References
- Why NASA’s new photos of the moon look super fake (even though they’re not) – Washington Post
- Albedo – Wikipedia
- Geometric albedo – Wikipedia