An annular eclipse is an unusual and interesting variation on total eclipse when the moon's disk is too small to cover the whole of the sun. They are worth travelling to see particularly when they occur in scenic locations.
The slightly elliptical orbits of the Earth around the Sun and the Moon around the Earth give rise to variation in the apparent size of the Moon and Sun over the course of the year and lunar cycle. If the Moon is near to its furthest point from Earth and the Sun is near its closest point to the Earth then the Moon's disk will not cover the whole of the Sun's disk resulting in an annular eclipse where the outer edge of the Sun is visible surrounding the Moon like 'bright ring of fire'. Whilst much of the Sun's light is obscured during an annular eclipse the sky does not go very dark. Unlike total eclipses, some thin cloud often adds to their effect. To find out more about annular eclipses please visit our annular eclipse guide.
Features worth looking out for include the projected images of the sun caused by the passing of light through narrow gaps in trees or other small apertures and the colours and tones of light on the ground and in the clouds. Unlike total eclipses, some thin cloud often adds to the effect.
In September 2016 Explorers will be running a tour to Southern Tanzania which will combine an annular eclipse with wildlife safaris in the Selous Game Reserve.