The dark side of the Earth

This animation shows the Moon passing between the Earth and Sun on a typical orbital cycle. The inclined orbit of the Moon means that a solar eclipse, let alone a total solar eclipse, does not happen every month.

When a solar eclipse does occur, the Moon blocks the Sun from the point-of-view of the Earth and casts its shadow on the surface of the Earth below. On 2 July 2019, a total solar eclipse will take place over South America. ESO's La Silla Observatory is situated within the path of totality..