The partial lunar eclipse of 28 August 2026

At maximum, 06:12:49 mainland time and 05:12:49 in the Canaries, 96.6% of the lunar disc's surface will lie inside Earth's umbra. Measured across the diameter, which is how the magnitude of a lunar eclipse is normally quoted, the figure is 0.937. The Moon crosses the southern half of the shadow, and the only part left outside is a sliver of the northern limb, a little over 6% of the diameter.

That sliver is what makes the eclipse both awkward and beautiful. The six hundredths of the disc still catching direct sunlight are vastly brighter than the rest and they dazzle: the reddish grey of the eclipsed portion only reads properly if you look away from the bright edge or raise a pair of binoculars. In a total eclipse that contrast is gone, which is why totals turn red at once while a deep partial like this one makes you wait for your eyes to adapt.

This deserves saying plainly, because this site has spent months warning of the opposite for solar eclipses: looking at a lunar eclipse carries no risk at all. Naked eye, binoculars, telescope or phone, with no filter of any kind, for as long as you like. You are looking at the full Moon, sunlight reflected and dimmed hundreds of thousands of times over, fainter still during the eclipse.

The difference is what passes in front of what. In a solar eclipse the Moon moves in front of the Sun, and only the narrow strip of the planet its shadow sweeps gets to see it. In a lunar eclipse it is Earth that comes between, and the shadow it casts is so large that the event happens at the same instant for everyone: this morning's contacts are identical in Cadiz and in Girona. The only thing that changes is whether your horizon lets you reach the end.

The Moon enters the penumbra at 03:23:36 mainland time, and that phase is close to a formality: it dulls the disc so slightly that little shows before its final half hour. The real eclipse starts at 04:33:23, when the edge touches the umbra, and the bite grows for one hour and thirty-nine minutes up to maximum.

The partial phase runs 3 hours and 19 minutes and closes at 07:52:14. The penumbral phase does not end until 09:02:02, but nobody in Spain sees that: by then the Moon has set in all 52 provincial capitals. As the bite begins the Moon stands between 24.9 degrees high in Girona and 45.3 in Santa Cruz de Tenerife; by maximum it has dropped to between 10.2 and 30.3, always towards the west-southwest.

All 52 capitals reach maximum with the Moon above the horizon, so the 96.6% view is guaranteed nationwide. The ending is not: only 17 see the partial phase finish, and in the other 35 the Moon sets still bitten.

What decides the split is longitude. In Girona the Moon sets at 07:17:29 with 47.1% of its diameter still inside the umbra; in Barcelona at 07:21:03 with 42.7%; in Palma at 07:20:51 with 43.0%; in Valencia at 07:33:51 with 26.3%; in Madrid at 07:46:37 with a residual 9.0%. Pontevedra, the last of them, keeps it until 08:04:53, a good twelve minutes after the eclipse is over: 47 minutes and 24 seconds separate the earliest moonset from the latest.

Even so the deal is decent: Girona still gets 164 of the 199 minutes of partial phase, 82.5% of it. What is lost is not the eclipse but its ending. Two capitals land on the knife edge: in Leon the Moon sets 17 seconds before the last contact, in Oviedo one second after. At that scale the terrain decides, because these times assume a clean sea-level horizon.

On the islands everything happens an hour earlier by the local clock: the bite starts at 03:33:23, maximum falls at 05:12:49 and the partial phase closes at 06:52:14. The advantage is not only the clock. In Las Palmas de Gran Canaria and Santa Cruz de Tenerife the Moon reaches maximum at 29.9 and 30.3 degrees of altitude, nearly three times higher than in Girona, with the Sun 30 degrees below the horizon: full night.

There is no race against moonset either. The Moon does not set in Las Palmas until 07:47:38, nor in Santa Cruz until 07:50:29, close to an hour after the eclipse has ended. They are the only two capitals that see it complete, contact to contact.

One oddity only shows up when you cross the two columns of the table. In 44 of the 52 capitals the Sun rises in the east before the eclipsed Moon sets in the west: for a few minutes both bodies sit above the horizon at once, with Earth in between casting its shadow on one of them. Geometrically it should be impossible to see, and it happens because atmospheric refraction lifts both images above their true positions. It is called a selenelion.

The windows are short and much alike: 9.2 minutes in Oviedo, 8.7 in Bilbao, 8.5 in Madrid, 7.5 in Barcelona. Badajoz misses it by twenty-nine seconds, because there the Sun rises at 07:52:43 and the partial phase closes at 07:52:14.

A clear horizon to the west, leaning slightly south: the Moon sets at azimuth 258 degrees, some twelve degrees left of due west. The later it gets the lower it sits and the more atmosphere you look through, so if you step outside once, make it between 05:30 and 06:30 mainland time, with maximum inside.

After this, the lunar calendar goes quiet. The next three eclipses, in February, July and August 2027, are penumbral: zero umbral obscuration, invisible to the naked eye, and two with the Moon below the Spanish horizon anyway. The next genuine partial, on 12 January 2028, bites just 2.7% of the disc. To see the whole Moon inside the shadow again you must wait for the total of 31 December 2028, and from Spain it comes up already eclipsed: at maximum it is pinned to Madrid's horizon, 0.3 degrees below.