Earthshine Proves the Moon Obscures the Sun During a Total Solar Eclipse

During a total solar eclipse, the Moon is right between the Earth and the Sun. Thus, the near side of the Moon does not receive any sunlight. But while it is dark, it still gets some light reflected by the surface of the Earth. This phenomenon is called Earthshine.

Some flat-Earthers argue that a solar eclipse is not caused by the blocking of the Sun by the Moon, but by another, mysterious celestial body. The reason is that eclipses are incompatible with their beliefs about the motion of the Sun and the Moon.

Earthshine proves that they are wrong.

Earthshine is evidence that the Moon is blocking the Sun from view during a total solar eclipse. The observation is very simple and straightforward. It does not require careful observation or complex calculations.

Our eyes cannot observe the Earthshine directly. The reason is that Earthshine is very dim, and a solar eclipse happens during the day. Our eyes are already accustomed to bright daylight conditions. A total solar eclipse lasts only for a few minutes, and there is not enough time for our eyes to adapt to the sudden dark situation.

Earthshine can be observed during a total solar eclipse using long exposure photography. The familiar figure of the Moon will be easily recognizable.

Earthshine Photography Tricks

If you want to take pictures of earthshine during a total solar eclipse, please note the following:

  • It is not advisable to try to take the picture of earthshine during a partial solar eclipse. The intensity of sunlight can damage camera equipment, or worse, your eyes.
  • According to, a suitable exposure is ISO 100, f/8, 8s, or equivalent. Take several different exposures using bracketing.
  • If you get enough different exposure, you can make HDR images of the eclipse and put more features in the picture other than earthshine.
  • Because of long exposure, a solid tripod or mount is required.
  • Note the time of the eclipse. You only have a few minutes. Make sure everything is done before the eclipse ends.


The illustration is a total solar eclipse by The picture was taken in Tidore, Indonesia during the total solar eclipse in 2016.

The picture is a composite of multiple images with different exposure (HDR).