When is the 27–28 August 2026 partial lunar eclipse?

NASA GSFC lists penumbral begins 01:24 UT, partial begins 02:34 UT, greatest eclipse 04:13 UT, partial ends 05:52 UT, and penumbral ends 07:02 UT, all on 28 August 2026. NASA SVS notes the eclipse is visible in the Americas (except Alaska and northwestern Canada), western Europe, and western Africa, and falls on the evening of the 27th in US time zones.

What NASA numbers does this field note cite?

From NASA GSFC Eclipses During 2026: greatest eclipse UT 04:13 (TD 04:14:04, ΔT 75.0 s), umbral magnitude 0.9299, penumbral magnitude 1.9645, gamma 0.4964, Saros 138. From NASA SVS: at greatest eclipse about 96.3% of the Moon's disk is in Earth's umbra. Umbral magnitude is a diameter fraction; the 96.3% figure is disk area. This note does not invent other catalog numbers.

Is this lunar eclipse a Sun–Moon opposition in the Charting Stars engine?

A lunar eclipse is astronomically a Sun–Moon opposition. At NASA's 04:13 UT clock the engine places the Sun at 4°54′ Virgo and the Moon at 4°50′ Pisces — 179.94° apart, 0.06° from exact opposition, inside the published 2.0° solar transit orb. That is live geometry, not a forced named contact.

Where does the eclipse axis fall in my houses?

This note does not invent house placements for a generic reader. An eclipse axis is two tropical longitudes; houses need your birth time and place. Cast at /chart to see where that axis lands in your houses. The live sky, recomputed on request, is on /sky-now.

How were these longitudes computed?

The same observatory pipeline as /sky-now and a free chart on /chart: VSOP87 geocentric tropical longitudes (D series for Mercury–Saturn, B series for Uranus and Neptune, Meeus for Pluto) at 2026-08-28T04:13:00.000Z. NASA supplies the clock and the eclipse catalog; the engine supplies the signs and degrees. We do not fabricate longitudes.

Partial lunar eclipse, 27–28 August 2026

Charting Stars reads the 27–28 August 2026 partial lunar eclipse at NASA's published greatest-eclipse instant, 04:13 UT on 28 August 2026, computing VSOP87 geocentric Sun and Moon longitudes at that clock and citing NASA GSFC for contact times, umbral and penumbral magnitudes, gamma, Saros, and visibility.

When is greatest eclipse for the August 2026 partial lunar eclipse?

NASA GSFC publishes greatest eclipse at 04:13 UT on 28 August 2026 (TD 04:14:04, ΔT 75.0 s). This field note uses that UT clock — 2026-08-28T04:13:00.000Z — and does not invent another. NASA SVS notes the event falls on the evening of the 27th in US time zones.

Does Charting Stars invent the eclipse longitudes?

No. Contact times, umbral magnitude 0.9299, penumbral magnitude 1.9645, gamma 0.4964, and Saros 138 are NASA GSFC catalog numbers. Tropical Sun and Moon positions in this note are computed by the same VSOP87 pipeline as /sky-now at that NASA instant, not typed in by hand.

A lunar eclipse is a public sky. The observatory's job is to say when NASA says it happens, what the catalog numbers are, and — separately — where this engine's Sun and Moon sit at that instant. Those are different instruments. They are labeled as such.

NASA's Goddard Space Flight Center page Eclipses During 2026 lists a partial lunar eclipse on 28 August 2026. Greatest eclipse is 04:13 UT (Terrestrial Dynamical Time 04:14:04, ΔT 75.0 s). The phase clocks on that page, all on 28 August, are:

Penumbral begins 01:24 UT
Partial begins 02:34 UT
Greatest eclipse 04:13 UT
Partial ends 05:52 UT
Penumbral ends 07:02 UT

The same NASA page gives umbral magnitude 0.9299, penumbral magnitude 1.9645, gamma 0.4964, and Saros 138. We do not invent other catalog numbers, other gammas, or other clocks.

NASA Scientific Visualization Studio describes a deep partial: at greatest eclipse about 96.3% of the Moon's disk is in Earth's umbra. That 96.3% is disk *area*. NASA GSFC's 0.9299 is a *diameter* fraction. They are not the same measure. SVS also states the eclipse is visible in the Americas (except Alaska and northwestern Canada), western Europe, and western Africa, and that it falls on the evening of the 27th in US time zones.

This field note computes the tropical sky at NASA's greatest-eclipse instant: 2026-08-28T04:13:00.000Z. Longitudes below are VSOP87 geocentric positions from computeLivePositions, the same function behind Sky Now. They are not NASA RA/Dec, not house cusps, and not typed-in degrees.

The engine snapshot at 04:13 UT

At that UTC instant the tropical geocentric sky:

Sun 4°54′ Virgo
Moon 4°50′ Pisces
Mercury 5°22′ Virgo
Venus 20°02′ Libra
Mars 10°57′ Cancer
Jupiter 12°54′ Leo
Saturn 13°53′ Aries, retrograde
Uranus 5°37′ Gemini
Neptune 3°45′ Aries, retrograde
Pluto 3°12′ Aquarius, retrograde

No houses are listed. Houses need a birth time and a birthplace. This page does not invent them for a generic reader. Cast at /chart to see where the eclipse axis lands in *your* houses.

The engine's transit orbs stay as published (about 2° for the lights, down to 0.8° for the outers). Against the live sky at NASA's clock, this note names 3 contacts inside those orbs as geometry, not as fate:

Sun opposition Moon, 0.06° from exact
Mercury conjunction Sun, 0.46° from exact
Sun square Uranus, 0.72° from exact

Each named heading below is one of those engine contacts. A body can occupy the same season as the eclipse and still fall outside the published orb — we do not promote those near-misses into hits.

Sun opposite Moon at greatest eclipse

A lunar eclipse is the Moon moving through Earth's shadow at Full Moon. Full Moon is a Sun–Moon opposition on the ecliptic. This heading ships only because the engine actually placed the lights there.

At 2026-08-28T04:13:00.000Z the tropical Sun is at 4°54′ Virgo. The Moon is at 4°50′ Pisces. Their shortest arc is 179.94°, which is 0.06° from 180°. The engine's published solar transit orb is 2.0°. The contact is inside that cap. We did not widen the orb to make the sentence true.

That is the eclipse axis as this observatory can state it: two geocentric longitudes, nearly opposite, at NASA's clock. It is not a house system. It is not a medical claim. It is not a verdict about anyone's chart. The axis is a line in tropical longitude. Where it cuts *your* wheel is a question for your own chart.

Mercury with the eclipse Sun

Live Mercury is at 5°22′ Virgo. The eclipse Sun is at 4°54′ Virgo. Mercury conjunction Sun, 0.46° from exact.

Mercury is the fast inner body; at this instant it sits on the solar side of the axis, still inside Mercury's 1.5° transit orb. That is a sky fact at NASA's clock, not a personality reading and not a forecast. If the engine had left Mercury outside that cap, this heading would not be here.

Uranus square the eclipse Sun

Uranus is at 5°37′ Gemini. The eclipse Sun is at 4°54′ Virgo. Sun square Uranus, 0.72° from exact. The Moon at 4°50′ Pisces is likewise 0.78° from a square to Uranus, inside Uranus's 0.8° transit orb.

A square is 90° of ecliptic. Uranus is the slow body here; the lights are the fast ones. The geometry is real at this instant and is reported because the engine returned it. It does not get a myth, a fate claim, or a house for a reader we have not met.

What this overlay is not

It is not a natal reading. It is not a celebrity page. It is not a parameterized eclipse family. It is not medical advice and it is not a claim that the sky will do something to you. Charting Stars computes positions; it does not sell fate. NASA timed the shadow. The engine timed the longitudes. Your houses, if you want them, are on /chart.

How the positions were computed

Every tropical longitude in this note comes from the Charting Stars engine — the same path as How Charting Stars Calculates a Birth Chart and the live table on Sky Now:

The clock is NASA GSFC greatest eclipse UT, encoded as 2026-08-28T04:13:00.000Z. Not a local-time guess.
Planetary longitudes from VSOP87 via astronomia, geocentric, with light-time correction. Uranus and Neptune use the VSOP87 B series; Pluto uses Meeus.
Named sky contacts use the engine's published transit orbs. We do not widen them to force an opposition heading.
NASA supplies umbral magnitude, gamma, Saros, phase times, and the SVS visibility/disk-area figures. If a degree is not in this article, we did not have it.

If you came to watch the Moon enter Earth's umbra, NASA has the map. If you came to see how this engine reads that same instant, the longitudes above are the reading. The live sky, recomputed on every request, remains at /sky-now.