Complete guide to the total solar eclipse of 2 August 2027

A total solar eclipse happens when the Moon passes exactly between the Earth and the Sun and its darkest shadow, the umbra, touches the surface. That shadow is a patch about 258 kilometres wide sweeping across the planet at over a thousand kilometres an hour. Only those inside the patch see totality; a few kilometres outside it, the spectacle disappears entirely.

Why the path is everything

The difference between 99% and 100% coverage is not one of degree, it is one of kind. At 99% the sky barely darkens, no corona appears and nothing memorable happens: Seville will see 98% coverage and will experience nothing resembling a total eclipse. At 100% the Sun disappears, stars and planets come out, the temperature drops and the horizon glows in every direction like a circular sunset. That is why all planning reduces to one thing: being inside the path.

The phases, in order

• First contact (C1): the Moon bites into the edge of the Sun. Nothing is noticeable without a filter. Just over an hour of partial phase begins.
• The last minutes: the light turns metallic, shadows sharpen and the temperature drops perceptibly. On the ground under trees, hundreds of crescent Suns appear.
• Shadow bands: seconds before totality, faint ripples of light and shade race across pale surfaces. They are hard to see and do not always appear.
• Second contact (C2): the last sliver of Sun breaks into bright points — Baily's beads — leaving a single flash, the diamond ring. This is when filters come off.
• Totality: the corona appears, white and filamentary, sometimes with red prominences at the edge. The horizon glows through all 360°.
• Third contact (C3): the diamond ring reappears on the other side. Filters back on immediately.
• Fourth contact (C4): the partial phase ends and the Sun is whole again.

What makes 2027 special

It is one of the longest total eclipses of the 21st century: at its maximum, over Egypt, totality reaches 6 minutes 23 seconds, where two or three minutes is typical. The reason is a fortunate combination: the Moon is near perigee, so it appears large, and the Earth is near aphelion, so the Sun appears small. The path also crosses one of the most reliably cloud-free regions on the planet in August.

For Spain this is a rare opportunity. Ceuta sits inside the path, with 4 min 48 s of totality, and after this eclipse and the annular one of January 2028, no total solar eclipse is visible from mainland Spain again until 2053.

What you actually see during totality

• The solar corona: the Sun's outer atmosphere, white and filamentary. It is the thing no photograph reproduces properly.
• Prominences: pink tongues of gas peeking past the edge of the lunar disc.
• Planets and bright stars in broad daylight. In August 2027 Venus and Mercury will be near the Sun.
• The horizon lit through 360°, with sunset colours in every direction at once.
• The Moon's shadow approaching and receding, visible over the sea or from high ground.

The minimum preparation

• ISO 12312-2 certified glasses for every person, bought well in advance.
• Accommodation inside the path for the night before.
• A chosen viewing spot and a backup in case of cloud.
• The exact time of totality where you will be, checked in the locator with your own coordinates.
• Water, shade and patience: it is August in the far south and the wait is long.