Why solar and lunar eclipses come in pairs — and what an eclipse season really is

We tend to hear about solar and lunar eclipses only in the days before they happen, often with the impression that they are unfolding in far-off or exotic parts of the world. For months, the sky follows the familiar rhythm of new and full moons, and then — seemingly out of nowhere — the sky delivers two major eclipses just weeks apart.

In reality, eclipses are neither random nor one-off events. Every eclipse is part of a predictable pattern — and they almost always arrive in pairs during a short and recurring window known as an eclipse season.

There are typically two eclipse seasons each calendar year. We’re almost upon the next one. Between Feb. 17 and Mar. 3, 2026, the first of two eclipse seasons in 2026 will produce two eclipses separated by exactly two weeks: an annular solar eclipse followed by a total lunar eclipse.

What is an eclipse season?

An eclipse season is a period of 31 to 37 days, during which eclipses become possible. These seasons occur about every 173 days, or roughly twice per year — and every solar eclipse and every lunar eclipse you’ve ever heard about has taken place within one. Outside these windows, eclipses cannot occur.

Why? Because eclipses can only happen at new moon (solar eclipse) and full moon (lunar eclipse), when the Earth, moon and sun line up in space — an alignment astronomers call syzygy.

An eclipse season occurs when this alignment also happens close to the plane of Earth’s orbit around the sun, according to NASA. That plane defines the apparent path of the sun across Earth’s sky, and it has a special name — the ecliptic. When a new moon falls during an eclipse season, the moon’s shadow can fall on Earth to produce some kind of solar eclipse. When a full moon falls during the same window, the moon can pass into Earth’s shadow, causing a lunar eclipse.

Why isn’t there an eclipse every month?

Why Solar Eclipses Don’t Happen Every Month – Orbit Animation Explains – YouTube

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At first glance, eclipses might seem as though they should be monthly events. After all, there is a new moon every 29.5 days and a full moon just two weeks later. So why are eclipses relatively rare?

The reason lies in the tilt of the moon’s orbit. The moon orbits Earth on a path inclined by about 5 degrees relative to the ecliptic. As a result, most new moons pass slightly above or below the sun from our point of view, and most full moons pass above or below Earth’s shadow. In most cases, the precise alignment needed for an eclipse is missed.

Understanding the moon’s nodes

The key to understanding eclipse seasons lies in two invisible points in space known as the lunar nodes. These are the points where the moon’s tilted orbit crosses the ecliptic.

An eclipse season begins when the sun moves close to one of these nodes. For about a month, the geometry works out — new moons can produce solar eclipses and full moons can produce lunar eclipses. When the sun moves away from the node, the season ends, and eclipses become impossible again. According to long-term orbital calculations by NASA, the lunar nodes slowly regress westward by 19.3 degrees per year, shifting eclipse seasons by about 19 days each year.

Why solar and lunar eclipses come in pairs

Once an eclipse season begins, a pair of eclipses becomes almost inevitable. A new moon occurring near a node produces a solar eclipse when the moon passes between Earth and the sun. Roughly two weeks later, when the moon reaches full phase near the opposite node, Earth moves between the sun and the moon, producing a lunar eclipse. Or vice versa.

Occasionally, the timing works out so that a third eclipse can occur before the season ends, but most eclipse seasons deliver a pair.

2026’s first eclipse season: February-March 2026

The next eclipse season opens in mid-February 2026, providing a clear illustration of how eclipse pairing works in practice.

It begins on Tuesday, Feb. 17, 2026, with an annular solar eclipse, during which the moon will cover 96% of the sun to leave a slim “ring of fire” for up to 2 minutes and 20 seconds. However, it will be seen only from a small region of Antarctica, with a partial eclipse visible across Antarctica and parts of south-eastern Africa and South America.

Exactly 14 days later, on Tuesday, Mar. 3, 2026, the same eclipse season produces a total lunar eclipse, with the moon spending 58 minutes and 18 seconds fully inside Earth’s dark umbral shadow. Those in East Asia, Australia, the Pacific and western North America will get the best views of the moon, which takes on a reddish-coppery hue during totality.

2026’s second eclipse season: August 2026

The second and final eclipse season of 2026 is in August, and is arguably the more dramatic one because it includes something not seen on Earth since Apr. 8, 2024 — a total solar eclipse.

The eclipse season begins and peaks on Wednesday, Aug. 12, 2026, with a total solar eclipse. On that day, the moon will completely cover the sun for several minutes along a narrow path of totality that sweeps across Greenland, Iceland, and northern Spain. For observers within that path, daylight will briefly give way to darkness, temperatures will dip, and the sun’s outer atmosphere — the corona — will become visible to the naked eye. A deep partial solar eclipse will be visible across much of Europe, North Africa and the North Atlantic.

Just over two weeks later, on Wednesday, Aug. 28, 2026, the same eclipse season produces a partial lunar eclipse. Although less visually dramatic than a total lunar eclipse — a “blood moon” — the event will still see Earth’s shadow move across a significant portion of the moon’s surface, a special sight in itself. Observers across North America, South America, Europe and Africa will be well placed to watch the moon darken as it moves into the umbra.