Annular solar eclipse
During an annular solar eclipse, the Moon passes directly between the Sun and Earth. However, this happens when the Moon is at a point along its elliptical orbit where it is farther from Earth. As a result, it is too small to completely cover the Sun, leaving a ‘ring of fire’ in the sky.
The region of full shadow behind the Moon is called the ‘umbra’, highlighted in a lighter shade of blue in the image. During an annular solar eclipse, the umbra doesn’t quite reach Earth’s surface. The ring of fire is visible to viewers standing on Earth’s surface below the umbra where the Sun, Moon and Earth align.
Annular solar eclipses trace out a ‘band of annularity’ on Earth’s surface, which lies within the partially shaded ‘penumbra’ (darker, transparent blue region). The ‘ring of fire’ is only visible from within the band of annularity, while a partial eclipse is visible from the remainder of the penumbra. Other regions on Earth don’t see any eclipse at all.
The 2026–2028 ‘European solar eclipses’
Remember: never look directly at the Sun, even when partially eclipsed, without proper eye protection such as special solar eclipse glasses, or you risk permanent eye damage.
[Image description: This infographic explains how annular solar eclipses work. A central diagram shows the formation Sun-Moon-Earth, with the Moon tracing a shadow on Earth as it blocks the Sun's light. The fully shadowed region is labelled 'umbra'; this region does not quite reach Earth's surface, implying that we do not see the Moon fully blocking the Sun's light. A surrounding partially shadowed region, covering a large patch of Earth, is labelled 'penumbra'. The Sun, Moon and Earth themselves are also labelled. Dashed lines mark out the path of sunlight. A heading at the top says 'Annular solar eclipse' and the European Space Agency logo sits at the top right of the infographic.]
