When the sky darkens at midday, or the full moon turns a deep, burnished red, it can feel as though the universe has briefly broken its own rules.
Eclipses rank among the most dramatic celestial displays visible from Earth. And these events are not cosmic accidents. They are precise, predictable alignments governed by motion, light, and shadow.
Anywhere from four to seven times a year, the Earth, Moon, and Sun fall into near-perfect alignment, creating what astronomers call eclipses.
According to the National Aeronautics and Space Administration (Nasa), these events occur because the moon’s orbit around Earth is tilted relative to Earth’s orbit around the Sun. That five-degree tilt prevents eclipses from happening every month, but when the geometry locks into place, the result is a celestial shadow show that can transform the sky.
Two kinds of eclipses
There are two primary types: lunar eclipses and solar eclipses.
A lunar eclipse happens during a full moon, when Earth positions itself directly between the Sun and moon. Earth’s shadow falls across the lunar surface, dimming it, sometimes dramatically.
READ: Total lunar eclipse: Free public viewing set for March 3
A solar eclipse, by contrast, occurs during a new Moon, when the Moon moves between Earth and the Sun, casting its shadow onto Earth and blocking part or all of the Sun from view.
Though both occur several times each year, they differ sharply in how and where they are seen.
Lunar eclipses: Earth’s shadow on the Moon
Lunar eclipses are visible from roughly half of Earth at once. Anyone on the nighttime side of the planet can look up and witness the event. They unfold slowly, often over several hours.
Astronomers classify lunar eclipses into three types:
Total lunar eclipse
The moon moves entirely into Earth’s inner shadow, known as the umbra. During totality, the moon can glow a coppery red. It is a phenomenon popularly known as a “Blood Moon.”
The color comes from sunlight filtering through Earth’s atmosphere. Shorter wavelengths like blue and violet scatter easily, while longer wavelengths — red and orange — pass through and bend toward the moon. The more dust or clouds fill the Earth’s atmosphere, the redder the Moon can appear.
Partial lunar eclipse
An imperfect alignment causes only part of the moon to pass through Earth’s umbra. A curved shadow appears to “bite” into the lunar disk before receding.
Penumbral eclipse
The subtlest of the three, this occurs when the moon travels through Earth’s outer shadow, the penumbra. The dimming is slight, so slight that casual observers may miss it entirely.
Upcoming lunar eclipses include a total eclipse on March 3, 2026, visible across East Asia, Australia, the Pacific, and the Americas, and a partial eclipse on Aug. 28, 2026, visible from the East Pacific, the Americas, Europe, and Africa.
Why the moon turns red
The same physics that paints sunsets crimson also colors a totally eclipsed Moon.
Sunlight appears white but contains the full spectrum of colors. Blue light scatters more readily into Earth’s atmosphere, which is why skies appear blue during the day. At sunrise and sunset, sunlight travels a longer path through the atmosphere; the blue light scatters away, leaving reds and oranges to dominate.
During a total lunar eclipse, sunlight reaching the moon first passes through a thick slice of Earth’s atmosphere, effectively projecting every sunrise and sunset on the planet onto the lunar surface at once. The result: a muted, ember-like glow against the night sky.
Solar eclipses: the moon’s shadow on Earth
Solar eclipses, though just as frequent globally as lunar eclipses, are far rarer to witness from any one location. That is because the Moon’s shadow on Earth is comparatively narrow, only about 300 miles (480 kilometers) wide at most.
The Moon’s shadow has two parts:
Umbra — where the Sun is completely blocked, producing a total solar eclipse.
Penumbra — where the Sun is only partially obscured.
Observers within the umbra experience totality, often lasting only a few minutes. Within that brief window, daylight fades, temperatures can drop, and the Sun’s outer atmosphere — the corona — becomes visible.
Despite the shadow’s narrow path, Earth’s rapid rotation allows the eclipse track to sweep across vast distances before the alignment shifts.
Upcoming solar eclipses include a total eclipse on Aug. 12, 2026 (UTC), visible from Greenland, Iceland, Spain and parts of Russia and Portugal; an annular eclipse on Feb. 6, 2027 (UTC), visible from Chile and Argentina; and another total eclipse on Aug. 2, 2027 (UTC) crossing North Africa and parts of the Middle East.
Why eclipses are not monthly events
If the moon orbits Earth every month, why don’t we see eclipses monthly?
The answer lies in orbital tilt. The Moon’s orbit is inclined about five degrees relative to Earth’s orbit around the Sun. Most months, the Moon passes slightly above or below the line connecting Earth and the Sun.
Only when the alignment occurs near the points where the two orbital planes intersect, known as nodes, can an eclipse take place.