The solar eclipse arriving Wednesday, Aug. 12, will transform daytime skies across a narrow section of the Northern Hemisphere as the moon moves directly between Earth and the sun.

The 2026 total solar eclipse will cross Greenland, Iceland, northern Russia, the Atlantic Ocean, Spain and a small portion of Portugal, while a much larger region will experience a partial eclipse.

Solar Eclipse is a Sun Shadow

A total solar eclipse occurs when the moon passes between Earth and the sun and its dark inner shadow, called the umbra, reaches Earth's surface.

People inside the path of totality briefly see the moon completely cover the bright face of the sun. Outside that narrow path, observers see only a portion of the sun disappear behind the moon.

The Aug. 12 eclipse will unfold in five principal stages, beginning with the first contact of the moon and sun and ending when the moon completely leaves the sun's disk.

Stage 1: The Partial Solar Eclipse Begins

The first stage begins at first contact; the moment the moon's edge appears to take its first bite from the sun.

The partial eclipse will be visible across a broad area, including parts of North America, Europe and Africa. In Alaska, the partial eclipse begins in the morning, while other locations will see the event later in the day.

For observers in the path of totality, the moon will gradually cover more of the sun. The bright solar disk will become a narrowing crescent as the eclipse approaches its most dramatic phase.

The changing light can produce noticeable effects on the landscape. Shadows may become unusual, temperatures can fall and the sky can take on an increasingly eerie appearance.

One especially interesting effect occurs when sunlight passes through small openings between leaves. Instead of producing ordinary circular patches of light, the openings can project tiny crescent-shaped images of the partially eclipsed sun onto the ground.

Stage 2: Second Contact and the Approach of Totality

The second stage begins as totality approaches and some of the most spectacular visual effects occur.

The final portion of sunlight can produce the diamond ring effect, in which a bright point of sunlight appears alongside the dark silhouette of the moon. Another phenomenon, known as Baily's beads, occurs when sunlight shines through valleys and irregularities along the moon's edge.

As the last sunlight disappears, the moon's shadow races across the landscape. The transition from daylight to the darkness of totality can happen remarkably quickly.

Observers should also watch the horizon. While the area directly beneath the eclipse becomes dark, distant portions of the landscape can remain illuminated, creating an unusual ring of twilight.

Stage 3: Solar Eclipse Totality 

The third stage is the main event: totality.

During totality, the moon completely covers the sun's bright surface. NASA says totality will last less than two and a half minutes even near the center of the eclipse path, with many locations experiencing less than two minutes of complete darkness.

For the first time during the event, people who are directly inside the path of totality can safely look at the eclipsed sun without solar viewing glasses. The moon blocks the intensely bright photosphere, allowing the sun's much fainter outer atmosphere, or corona, to become visible.

The corona can appear as a white, wispy halo surrounding the moon. Solar prominences may also become visible along the edge of the moon.

Solar Eclipse Maximum

Maximum eclipse occurs approximately halfway through totality, when the moon is positioned most directly between Earth and the sun.

The temporary darkness can also make bright planets and stars visible. NASA notes that the exact appearance of the sky will depend on the observer's location and conditions.

NASA plans extensive coverage of the event, including scientific observations of the sun's corona. Researchers will use aircraft and balloons to study how the temporary darkness affects Earth's atmosphere.

Stage 4: Totality Ends

The fourth stage begins when the sun's bright surface starts emerging from behind the moon.

The end of totality can produce another diamond ring effect and a new display of Baily's beads. As more of the solar surface becomes visible, the sky begins returning toward normal daylight.

This moment also marks the end of the brief period when it is safe to look directly at the sun without specialized eye protection.

Anyone who continues watching the eclipse must immediately put solar viewing glasses back on before the sun's bright surface reappears.

Stage 5: The Partial Eclipse Ends

The final stage is the waning partial eclipse.

The moon continues moving across the sun until its silhouette gradually leaves the solar disk. The crescent grows larger and larger until the sun once again appears as a normal, unobstructed disk.

The eclipse eventually ends at fourth contact, the astronomical term for the moment the moon's edge completely leaves the sun.

The Aug. 12 eclipse will therefore begin as a subtle partial eclipse, reach a dramatic period of darkness for those fortunate enough to be in the path of totality, and then gradually return to ordinary daylight.

What to Expect During the Solar Eclipse

• A growing solar crescent: The moon will gradually cover more of the sun during the partial phase.
• Changing temperatures: The air can become noticeably cooler as sunlight is blocked.
• Strange shadows: Crescent-shaped shadows can appear beneath trees and through other small openings.
• Baily's beads: Brief points of sunlight can shine through valleys along the moon's edge.
• The diamond ring: A brilliant point of sunlight can appear beside the moon immediately before or after totality.
• Rapid darkness: Areas inside the path of totality can experience a sudden transition from daylight to twilight-like conditions.
• The solar corona: During totality, the sun's normally hidden outer atmosphere becomes visible.
• Possible planets and stars: Bright celestial objects can become visible during the brief darkness.
• A rapidly changing landscape: Light and shadows can shift dramatically as the moon's shadow passes overhead.
• A return to daylight: After totality, the sun reappears as a growing crescent before the eclipse eventually ends.

Where the 2026 Eclipse Will Be Visible

The path of totality stretches across a remote portion of the Northern Hemisphere, beginning in far northern Russia before moving across the Arctic and North Atlantic, Greenland, Iceland and northern Spain. A small part of Portugal also falls within the totality zone.

Cities such as Reykjavik, Iceland, and several Spanish cities will experience totality. NASA lists totality beginning at approximately 5:48 p.m. local time in Reykjavik and around 8:28 p.m. in León, Spain.

Millions of other people will see a partial eclipse. In the United States, portions of the country from Alaska to North Carolina will experience at least some degree of partial coverage, although the percentage of the sun covered will vary considerably by location.

Eclipse Viewing Safety

Eye protection remains critical throughout the partial phases. Looking directly at the uneclipsed or partially eclipsed sun can cause serious and permanent eye injury.

NASA recommends using eclipse glasses or handheld solar viewers that meet appropriate safety standards. Ordinary sunglasses are not an adequate substitute. Specialized solar filters are also required when using cameras, binoculars or telescopes to observe the sun.

The only exception is the short period of totality, when the moon completely blocks the sun's bright face. Solar viewers must be put back on before the sun begins emerging.

More Information

• NASA: Total Solar Eclipse of Aug. 12, 2026
• NASA: Eclipse Maps and Viewing Information
• NASA: 2026 Eclipse Coverage and Livestream Information
• NASA: Solar Eclipse Viewing Safety
• NASA: August 2026 Eclipse Animations