Lunar eclipse · next

Partial lunar eclipse, 28 August 2026

A real bite out of the disc, with a hard curved edge. Obvious to anyone who looks up, and obvious in a photograph taken on a phone. Umbral magnitude 0.938 — the fraction of the Moon’s diameter that Earth’s dark shadow covers at its deepest.

Without JavaScript

Everything below still holds. Every date, time and magnitude on this page is computed from the orbital series rather than looked up in a table, and with scripting off you are seeing the copy that was computed when this site was last built — dated at the foot of the page, and given in UTC, because a build has no way of knowing what clock you keep. With scripting on, the same numbers are worked out again on your device in your own zone. The explanation is the whole method either way.

The shadow, to scale

Outer ring penumbra Inner disc umbra Dashed line the Moon’s path

Earth’s umbra is about 2.7 times the width of the Moon, which is why a total lunar eclipse can last more than an hour while a total solar eclipse lasts minutes. The umbra is drawn 2% larger than pure geometry gives, the standard allowance for Earth’s atmosphere — and that same bent, reddened light is the reason a totally eclipsed Moon is copper rather than black.

The stages, in your own clock

Stage	What happens	Time
P1	Penumbra first touches the Moon	01:22
U1	Umbra first touches — the bite begins	02:33
—	Greatest eclipse	04:13
U4	The bite closes	05:52
P4	The Moon leaves the penumbra	07:03

Times in UTC, because this copy of the page was written before there was a reader to have a clock — the Moon is inside the umbra for 3h 19m, and inside the penumbra for 5h 42m altogether.

Will you see it

Unlike a solar eclipse, this one looks the same from everywhere on Earth — there is no path to be inside or outside of. The only question is whether the Moon is above your horizon while it happens. That needs your latitude, so it is asked for rather than assumed, and the answer is worked out on this device and sent nowhere.

This one needs JavaScript, and it is the only thing on the page that does — the horizon question is the only one whose answer depends on where you are, so it cannot be worked out in advance and written into the page for everybody.

Further out

Every lunar eclipse for the next ten years, with how deep each one goes and how long it lasts.

The next ten years →

How this is computed →

Method · Sun and Moon from Meeus’ abridged VSOP87 and ELP2000 series (longitude, latitude and distance), umbra and penumbra from the Moon’s horizontal parallax with the customary 2% atmospheric enlargement, magnitudes in units of the Moon’s diameter. No ΔT is applied, so the times run about a minute late. Nothing is fetched and nothing is logged.

Computed 13 August 2026, when this page was built, and shown in UTC. Nothing here is a stored table — but nothing here is live either, until your browser opens it. Every number on this page is then worked out again on your device, from the same series, in your own clock.