Total solar eclipse around totality. Time-lapse sequence of 28 images from just before totality (far left) to totality (centre) and just after totality (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, not shown) 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.