Total solar eclipse. Time-lapse sequence of eleven images from just after first contact (far left) to totality (centre) and just before last contact (far right) for a total solar eclipse. 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 Idaho in the USA on 21 August 2017. Totality lasted for just over 2.5 minutes. The time from first contact to last contact was just over 3 hours.