While 12 August gave us a majestic astronomical show, in the early hours of 28 August 2026 another remarkable celestial event will take place: a partial lunar eclipse. On this date, the full Moon will pass into the Earth's shadow, darkening much of its disc and creating a sight few people have ever seen.
How does it happen?
A lunar eclipse occurs when the Earth comes between the Sun and the Moon, casting its shadow onto our satellite. The full Moon gradually “disappears” as it enters the umbra (the central part of the shadow) and grows darker. This happens because the full Moon sits directly behind the Earth, opposite the Sun.
Why doesn't it happen every month?
Plenty of people ask the same thing: if solar eclipses happen at new Moon (when it lies between the Sun and the Earth), and lunar eclipses at full Moon (when it lies behind the Earth, opposite the Sun), why don't we get eclipses every month?
Image: phases of the Moon according to its position relative to the Earth and the Sun.
The reason is simple, and it only takes a little geometric imagination to grasp it. The Moon's orbit around the Earth and the Earth's orbit around the Sun lie in different planes. The two planes differ by about 5º, which means the three bodies are not always lined up and the Earth's shadow falls wide of the Moon, and vice versa. Only when the Moon, along its orbit, crosses the line of nodes (where the two planes intersect) are the Earth, Sun and Moon in a position for an eclipse. That line of nodes also has to be pointing towards the Sun. The figure below illustrates exactly what we've just described:
Image: diagram of the Earth-Sun and Moon-Earth orbital planes. The Moon's shadow does not always fall on the Earth (and vice versa) because the conditions are not always met. Credit: Instituto de Astrofísica de Canarias (IAC).
Two eclipses in a single month. Coincidence?
Not really. In fact, the usual pattern is a lunar eclipse followed by a solar one, and vice versa. With this lunar eclipse we reach the final stage of the same eclipse season that began with the total solar eclipse on 12 August. During each eclipse season, the conditions we've just seen come together and allow these events to happen. This occurs roughly once every six months and lasts about 35 days. If there is a new Moon during that period, there will be a solar eclipse. Some two weeks later, at full Moon, the lunar eclipse takes place.
Times and visibility in the Canary Islands
The partial lunar eclipse will begin in the early hours of Friday 28 August. For the Canary Islands (UTC+1, summer time) the key moments are as follows:
02:24 → Start of the penumbral phase. The Moon enters the outer shadow, producing a faint dimming.
03:34 → Start of the partial phase. The Moon begins to enter the umbra and the Earth's “bite” becomes visible.
05:13 → Maximum of the eclipse (peak of the partial coverage).
06:52 → End of the partial phase (the Moon leaves the umbra).
In the Canaries the Moon will set after the partial eclipse has ended (at around 7:00), unlike central and eastern mainland Spain, where the Moon sets earlier. So on the islands the partial phase can be seen in full. During the eclipse the Moon will move towards the west-southwest horizon; at maximum it will be some 30° above the horizon in the Canaries, and it will set close to due west.
As for where it can be seen, it will be visible from all of Spain, and also across much of Europe, Africa, the Americas and western Asia. In the Canaries we'll be able to watch the eclipse with the Moon still high in the sky, and enjoy the whole partial phase without the Moon disappearing halfway through.
How much of the Moon will be covered?
Here's a curious detail: there's no need to worry about what percentage of the Moon will be covered. Unlike a solar eclipse, the amount of coverage is the same wherever you watch from. In this case we'll have a partial eclipse (the Moon won't go completely dark) with a magnitude (fraction of the lunar diameter covered) of 0.93 (93% coverage).
How to watch it
A few useful tips:
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Location. Find a spot with a clear horizon towards the west-southwest, as the Moon will move in that direction as dawn approaches.
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Equipment. If you like, use binoculars or a small telescope to pick out extra detail: the lunar mountains and craters, and even the faint reddish colour of the eclipsed part. During the partial phase (and especially at maximum) the area inside the umbra can take on reddish or coppery tones, because the Earth's atmosphere filters out blue light and refracts red light onto the Moon (the same effect that turns the Sun red at sunrise).
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No protection needed. Unlike a solar eclipse, for this lunar eclipse you don't need any glasses. Moonlight poses no risk to your eyes.
In short, the lunar eclipse of 28 August will be easy to see: just look up at the Moon at those times and enjoy the show.
One last thought
This lunar eclipse rounds off an extraordinary August in the sky. On 12 August we witnessed a solar eclipse (total on the mainland), and two weeks later the full Moon of 28 August closes the month's astronomical cycle with this partial eclipse. Plan your viewing around the local times in the Canaries and follow the tips above, and you'll be able to enjoy this memorable lunar event from the islands.
