“The Sun and the Moon have been observed to appear in the sky at the same time during a total lunar eclipse. This cannot happen if the Earth is round because the Sun, Earth and Moon are supposed to be in a straight line during a total lunar eclipse. So, the globe Earth model is wrong!”
Some flat-Earthers observed the Sun and Moon appear at the same time during a total lunar eclipse. Predictably enough, they pick the most far-fetched explanation, and conclude the Earth is not round. But in reality, this phenomenon is well documented and clearly explained.
During a total lunar eclipse, the position of the Sun, Earth, and Moon is in a straight line. In this configuration, both the Sun and Moon should not be visible at the same time during a lunar eclipse.
But it turns out the atmosphere of the Earth refracts light. As a result, the actual position of the Moon is about 0.5° lower than where it appears. And the same thing happens with the Sun at the opposite point in the sky. This is how it is possible to observe both objects in the sky at the same time during a total lunar eclipse.
This phenomenon is called ‘selenelion’ or ‘selenehelion’. While certainly not impossible, it is a very rare and unique phenomenon, and can only happen at specific place and time during the progression of a total lunar eclipse.
- Lunar eclipse – Wikipedia