This is the latest accepted revision, reviewed on 27 April 2019. Totality during the 1999 solar eclipse. An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer. The term eclipse is most often used to describe either a solar eclipse, when the Moon’s shadow crosses the Earth’s surface, or a lunar eclipse, when the Moon moves into the Earth’s shadow. For the special cases of solar and lunar eclipses, these only happen during an “eclipse season”, the two times of each year when the plane of the Earth’s orbit around the Sun crosses with the plane of the Moon’s orbit around the Earth.