Total solar eclipse. Time-lapse sequence of images from just after first contact (far left) to totality (centre) and just before last contact (far right) for a total solar eclipse. The diamond ring effects just before and after totality are also shown. Total solar eclipses occur when the Moon passes directly in front of the Sun. Total solar eclipses usually occur less than once a year, and can only be seen from a small area of the Earth's surface. At totality, the solar atmosphere (corona, white) becomes visible. This total solar eclipse was observed from Cerro Tololo Observatory, Chile on 2 July 2019.