Solar eclipse
During a solar eclipse, the Moon passes between the Sun and Earth. As they align, the Moon completely or partially covers the Sun.
The region of full shadow behind the Moon is called the ‘umbra’, highlighted in a lighter shade of blue in the image. A total solar eclipse (where the Moon covers the Sun completely) is visible from within the umbra. The strip of land traced out by the umbra on Earth’s surface is called the ‘band of totality’.
The region of partial shadow cast by the Moon is called the ‘penumbra’ (darker, transparent blue region). A partial eclipse is visible from regions on Earth within the penumbra. Other regions on Earth don’t see any eclipse at all.
The white dashed lines indicate how rays of sunlight travel from the Sun to Earth. Because these rays travel in straight lines, tracing these rays from the Sun’s edges also traces out the umbra and penumbra.
A total solar eclipse can last up to a few minutes, while a partial solar eclipse can last for an hour or more.
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 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'. A surrounding partially shadowed region 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 'Solar eclipse' and the European Space Agency logo sits at the top right of the infographic.]
