🌕 Next Lunar Eclipse Countdown

A lunar eclipse occurs when Earth passes directly between the Sun and the full Moon, casting Earth's shadow onto the lunar surface. The Moon does not emit its own light — it shines by reflecting sunlight. When Earth blocks that sunlight, the Moon dims or darkens. Lunar eclipses only occur at full Moon, and only when the full Moon is near one of the two nodes where the Moon's orbit crosses the ecliptic (Earth's orbital plane around the Sun) — because the Moon's orbit is tilted about 5.1° relative to Earth's orbit, most full Moons pass above or below the shadow entirely.

The Moon's orbital plane is inclined 5.1° to the ecliptic. During most full Moons the Moon is displaced above or below Earth's shadow cone in three-dimensional space and no eclipse occurs. A lunar eclipse requires the full Moon to fall within about 1.5° of an orbital node at the same time. This geometry repeats two to four times per year globally, with total umbral eclipses being a subset of those events.

Earth casts two nested shadows: the umbra (dark central cone where all direct sunlight is completely blocked) and the penumbra (larger outer cone where only some sunlight is blocked). In a total lunar eclipse, the entire Moon is immersed inside the umbra — it turns red-orange (the Blood Moon). In a partial lunar eclipse, only part of the Moon enters the umbra — a distinct dark bite appears on the lunar disk. In a penumbral lunar eclipse, the Moon only passes through the penumbra — the dimming is gradual and often barely perceptible to the naked eye.

During totality, the Moon is entirely inside Earth's umbra and receives no direct sunlight. However, sunlight passing through Earth's atmosphere at every point along the terminator is refracted (bent) into the umbra and scattered onto the Moon. Earth's atmosphere acts as a filter: short-wavelength blue light is scattered away by gas molecules (Rayleigh scattering — the same process that makes sunsets red and the sky blue). Longer-wavelength red and orange light passes through and is refracted around Earth's limb to illuminate the Moon. The result is the Moon glows with the colour of every sunrise and sunset occurring simultaneously around Earth's circumference.

The Danjon scale (L) rates the darkness and colour of totality from 0 to 4. L=0: very dark, Moon nearly invisible. L=1: dark grey or brown, no detail visible. L=2: deep red or rust, slightly lighter at the edges. L=3: bright brick-red, often with a yellow border. L=4: copper-orange or bright, very vivid blue-white rim. The most important factor is Earth's atmospheric clarity: volcanic eruptions load the stratosphere with aerosols that absorb more light, producing darker, redder eclipses. The 1991 Pinatubo eruption caused subsequent eclipses to appear almost black.

The theoretical maximum duration of totality in a lunar eclipse is approximately 107 minutes — compared to the 7 minutes 32 seconds maximum for a total solar eclipse. This is because Earth's umbral shadow is about 2.7 times the Moon's angular diameter, so the Moon can traverse a long chord through it. Total duration depends on how centrally the Moon passes through the umbra and its orbital speed (slower near apogee means longer eclipse). Partial phases add another 1–2 hours before and after; the full event from first to last penumbral contact can span over 5 hours.

Six contact points define the complete timeline. P1: Moon enters Earth's penumbra — eclipse begins (invisible to eye). U1: Moon's limb first touches the umbra — partial phase starts; a dark bite appears. U2: Moon fully inside umbra — totality begins, Blood Moon phase. U3: Moon's leading limb starts exiting the umbra — totality ends. U4: Moon fully exits umbra — partial phase ends. P4: Moon exits penumbra — eclipse over. For penumbral-only events (like the upcoming 2026 eclipses), only P1 and P4 are defined, with no U contacts since the Moon never reaches the umbra.

Yes — completely safe. During a lunar eclipse you are watching the Moon, not the Sun. The Moon shines only by reflected or refracted light, its surface brightness during totality comparable to a very dim lamp — far less than normal moonlight. There is no UV or infrared hazard. You can observe with the naked eye, binoculars, or a telescope with no filter whatsoever, for as long as you wish. This is the exact opposite of a solar eclipse, where the unfiltered Sun causes instant, painless, and permanent retinal damage.

A total solar eclipse is visible in full only within the Moon's umbral shadow on Earth — a corridor 100–270 km wide. A total lunar eclipse is visible from the entire Earth hemisphere where the Moon is above the horizon — roughly half the planet simultaneously, often over 3 billion potential observers. The geometry is reversed: during a solar eclipse the small Moon casts a tiny shadow on big Earth; during a lunar eclipse big Earth casts a large shadow on the small Moon. Any location with a dark sky and the Moon above the horizon can watch without any travel.

The Saros cycle is approximately 18 years, 11 days, 8 hours (6,585.32 days) — the period after which the Sun, Earth and Moon return to nearly identical geometry, repeating a virtually identical eclipse. Babylonian astronomers had identified this cycle by at least 700 BCE. After one Saros, the repeat eclipse occurs about 120° west in longitude. Lunar eclipse prediction using Saros is accurate today, supplemented by modern numerical integration of the Moon's equations of motion (accurate to better than 1 second for events centuries out).

Penumbral magnitude is the fraction of the Moon's diameter that enters Earth's penumbra at maximum eclipse. Below 0.6, the dimming is essentially invisible to the naked eye. Between 0.7 and 0.9, the inner, darker part of the penumbra begins to show a faint grey shading on the Moon's limb — just barely perceptible. Above 0.9, the dimming on the Moon's dark side can be noticed if you know where to look. The upcoming 2026 penumbral eclipses are all shallow events with very low penumbral magnitude, well below the casual detection threshold.

The Moon's elliptical orbit carries it between 356,500 km (perigee) and 406,700 km (apogee). At perigee, the Moon moves faster — it crosses Earth's shadow more quickly, slightly reducing totality duration. At apogee, it moves more slowly and totality can last longer. A Super Moon eclipse combines the Moon being near perigee (larger, brighter disk) with a total lunar eclipse — producing a visually impressive Blood Moon that appears up to 14% larger and 30% brighter than a full Moon at apogee.

Modern prediction uses numerical integration of the gravitational equations of motion, incorporating over 1,000 known lunar orbital perturbation terms (Sun's gravity, Earth's oblateness, planetary influences). The ephemeris is calibrated using laser ranging data from retroreflectors placed on the Moon by Apollo astronauts, giving the Moon's position to millimetre precision. NASA's five-millennium eclipse catalog (eclipse.gsfc.nasa.gov) lists every lunar eclipse from 2000 BCE to 3000 CE with contact times accurate to better than one minute.

Lunar eclipses are excellent photography subjects — a DSLR, mirrorless, or modern smartphone works. No solar filter is needed at any stage. During partial phases: ISO 100–400, 1/250–1/1000 s, f/8. During totality the Moon is far dimmer: ISO 800–3200, f/5.6, 0.5–4 s. A telephoto lens (300+ mm) greatly enlarges the Moon. Shoot RAW and bracket ±2 stops — totality has significant brightness variation from the deep red umbral centre to the brighter edge. A sturdy tripod and remote shutter release prevent motion blur in the longer exposures.

A Super Moon occurs when a full Moon coincides with the Moon being near perigee, making it appear up to 14% larger and 30% brighter than at apogee. A Blue Moon is colloquially the second full Moon in a calendar month — it occurs roughly every 2.7 years and is not visually blue. A Super Blue Blood Moon is the rare coincidence of a Super Moon + Blue Moon + total lunar eclipse. The most recent vivid example was 31 January 2018, visible from Asia and Australia. Despite the dramatic name, it requires no equipment to watch.

Rayleigh scattering is the elastic scattering of electromagnetic radiation by particles much smaller than the wavelength of the light (like the N₂ and O₂ molecules in air). Its scattering intensity scales as λ⁻⁴ — meaning it scatters blue light (~450 nm) roughly 10 times more efficiently than red light (~700 nm). This makes the sky blue (scattered blue light seen from below) and sunsets red (blue light scattered away from the direct line of sight). During a lunar eclipse, sunlight refracted around Earth's limb traverses hundreds of kilometres of atmosphere, which removes virtually all blue and green light, leaving the red-orange band that creates the Blood Moon.

No to both. Tides are produced by the gravitational gradient of the Moon and Sun across Earth's diameter. A lunar eclipse occurs at full Moon, which already creates spring tides (Sun–Earth–Moon aligned). The eclipse itself does not change the positions of the Sun or Moon — only Earth's shadow falls on the Moon — so no new tidal forces arise. Earth's magnetic field is generated by motion of molten iron in the outer core and is not affected by the Moon's orbital position. Claims of unusual effects during lunar eclipses are not supported by systematic scientific evidence.

Lunar eclipses provided key scientific insights across history. Around 330 BCE, Aristotle used Earth's circular shadow on the Moon as evidence for Earth's spherical shape. Around 240 BCE, Aristarchus used the ratio of the Moon's diameter to Earth's umbral shadow width to estimate the Moon's distance and size — within 20% of the correct values. In 1504, Columbus used a predicted lunar eclipse from his almanac to intimidate Jamaican islanders into resupplying his expedition. In the 17th century, eclipse timing was used to determine longitudes at sea and to study Earth's rotation rate.

Both terms describe events where the Moon only passes through Earth's outer penumbral shadow, never entering the umbra. An "appulse" is an older term for a very shallow penumbral contact where the Moon barely grazes the penumbra and the dimming effect is essentially zero — undetectable. Modern usage often treats "penumbral eclipse" and "appulse" interchangeably. Many catalogs only list umbral eclipses (partial or total) as true eclipses, treating shallow penumbral events as astronomical curiosities. The 2026 penumbral eclipses in this dataset are shallow enough that most observers will see no perceptible change.

Deep inside totality, the Moon often shows a faint turquoise or blue-grey band around the edge of the umbral shadow — most visible in long-exposure photographs. This colour originates from sunlight filtered through Earth's ozone layer at high altitudes (around 40–50 km), which strongly absorbs red wavelengths, leaving blue-green light. Since this layer is thin and at the very edge of Earth's atmosphere, it creates a thin bright ring visible as a coloured fringe. The turquoise band is especially prominent during dark eclipses with a low Danjon rating and is one of the most photogenically striking features of a total lunar eclipse.

The lunar eclipses in this dataset through 2028 are all penumbral — none produce the dramatic Blood Moon of a total eclipse. For total lunar eclipse dates worldwide, NASA's five-millennium eclipse catalog at eclipse.gsfc.nasa.gov and timeanddate.com list every eclipse years into the future. Unlike solar eclipses, total lunar eclipses are visible from the entire nighttime hemisphere simultaneously — no travel to a specific narrow path is needed.