What happens during a total solar eclipse?

During a total solar eclipse, the Moon moves between the Earth and the Sun, completely covering the Sun’s disk from the perspective of observers in the path of totality on Earth. This alignment effectively blocks sunlight, plunging the area into darkness during the day. This phenomenon creates a significant visual spectacle, allowing observers to experience the Sun in a unique way.

Furthermore, during totality, the conditions are right for observers to see the Sun's corona, which is the outer atmosphere of the Sun. The corona is normally obscured by the bright light of the Sun, but during a total solar eclipse, it becomes visible due to the lack of sunlight reaching the Earth. Thus, while the first choice speaks specifically about the Moon blocking the Sun, it leads to the second phenomenon where the corona can be seen, further enhancing the experience of a total solar eclipse.

Other scenarios mentioned do not occur during a total solar eclipse; for instance, the Earth casting a shadow on the Moon pertains to a lunar eclipse, and the partial covering of the Sun describes a solar eclipse but not in its totality. Therefore, this context helps in understanding why the first choice accurately defines what happens during a total solar eclipse.