Image noise is a random variation of brightness or color information produced by a photo film or digital sensor. Image noise is an undesirable by-product of photography and does not come from the actual objects in the picture.
Image noise can be in the salt-and-pepper type, forming bright dots in the dark parts of the image. When appearing in the dark part of the Moon, flat-Earthers incorrectly claim they are stars, “proving” that the Moon is transparent. In reality, these are just image noise, not part of the actual objects.
Image noise is generally more noticeable with high sensitivity (ISO) settings, long exposure, or dark scenes.
In these pictures of the Moon, the noise is the salt-and-pepper type. It results in dark pixels in bright regions and bright pixels in dark regions. However, these are just noise. They are only visible in the pictures but not part of the actual objects.
The right picture was taken with the lens covered, so that light cannot reach the sensor, and anything other than black in the image is just noise. It was taken on ISO 3200 and 30 seconds long exposure. It almost perfectly reproduces the noise seen on the image of the Moon on the left. Astro-photographers sometimes exercise a technique called dark-frame subtraction to minimize the noise.
In short: The bright spots on the dark part of the Moon are not stars. They are just noise and not part of the real object. Light from stars cannot pass through the Moon. Furthermore, the Moon is not transparent.
References
- Image noise – Wikipedia
- Salt-and-pepper noise – Wikipedia
- Fixed-pattern noise – Wikipedia
- Dark-frame subtraction – Wikipedia