Total Lunar Eclipses of the 21st Century

Because the Moon’s orbit is tilted relative to Earth’s path around the Sun. Anywhere from four to seven times a year, Earth, the Moon, and the Sun line up just right to create an eclipse, and the tilt of the Moon’s orbit around Earth relative to Earth’s orbit around the Sun is the reason we have occasional eclipses instead of eclipses every month. More precisely, the Moon’s orbital plane is inclined about 5 degrees relative to Earth’s orbital plane, and eclipses can only occur when the Moon is near one of two points called lunar nodes, where its orbit crosses the ecliptic, during a full or new moon. Most months, the full Moon simply passes above or below Earth’s shadow rather than through it.

This comes down to something astronomers call an “eclipse season.” The Moon’s nodes slowly regress around Earth, completing a full cycle in about 18.6 years, but they line up with the Sun roughly every 173.3 days, or about 5.8 months. Each of these periods lasts a few weeks and allows one or two lunar eclipses, and typically one solar eclipse, to occur. A recent example makes this concrete: an annular solar eclipse on February 17, 2026, was followed exactly two weeks later by the total lunar eclipse of March 2 to 3, 2026, both part of the same eclipse season. Eclipses separated by a longer, more precise interval also repeat in a pattern astronomers call a Saros cycle. Similar solar and lunar eclipses repeat every 6,585.3 days, a bit more than 18 years, with the Sun, Moon, and Earth returning to nearly the same relative positions each time.

The color and brightness depend on exactly what is happening in Earth’s atmosphere at that moment, not on anything about the Moon itself. Volcanic eruptions are one of the most significant factors: eruptions that spew large amounts of ash into the air are generally followed by several years of unusually dark, deep red eclipses, and the 1991 eruption of Mount Pinatubo made the eclipse of December 9, 1992 so dark that many observers rated it a 0 on the five point brightness scale. That scale, devised by French astronomer André Danjon in 1921, runs from L=0 for a very dark eclipse where the Moon is almost invisible, up to L=4 for a very bright copper-red or orange eclipse with a distinctly bluish, bright shadow rim. So two total eclipses can look completely different depending on how much dust and cloud happen to be sitting in Earth’s atmosphere that night.

Because they genuinely are, and the reason is geometry rather than frequency. On average it takes about 375 years for a total solar eclipse to happen again at the exact same location, while a total lunar eclipse can be seen from any given spot roughly every 2.5 years. The difference exists because a solar eclipse is only visible from a very narrow path on Earth’s surface, whereas a lunar eclipse is visible from every location on the night side of the planet for as long as it lasts. In other words, you have to travel to a total solar eclipse, but a total lunar eclipse essentially travels to you, as long as it’s nighttime where you are.

They have, in some fairly consequential ways. Aristotle observed that Earth’s shadow always had a circular shape as it moved across the Moon during an eclipse, and reasoned that only a sphere could cast that kind of shadow, which became one of the earliest pieces of evidence that Earth was round. Centuries later, the phenomenon played a role in one of history’s more famous survival stories. According to an account by his son Ferdinand, Christopher Columbus, stranded in Jamaica in 1504, consulted an almanac and correctly predicted an upcoming total lunar eclipse. He warned the local Indigenous population that his gods were angry and would turn the Moon a bloody red color as a sign of their displeasure. When the eclipse arrived exactly on schedule, the account claims the Jamaicans agreed to resume supplying Columbus and his crew with food, though many historians remain skeptical of the story’s details.

It comes down to two things: how centrally the Moon passes through Earth’s shadow, and how close the Moon is to Earth at the time. The eclipses with the largest magnitude and longest totality all occur when the Moon passes almost perfectly through the center of the umbral shadow, and when the Moon is near perigee, its closest point to Earth, which is when the ratio of the Moon’s size to the umbra’s size is at its maximum. When both factors align, the Moon takes the longest possible path through the widest part of the shadow, stretching totality out toward the nearly 103 minute maximum. When the Moon instead grazes the shadow’s edge, or is farther from Earth and appears smaller relative to the umbra, totality can be as brief as a few minutes.

It’s simply two separate lunar phenomena happening to coincide, not a distinct type of eclipse. A Super Blood Moon combines a supermoon and a total lunar eclipse, resulting in a Moon that appears both larger and redder than a typical eclipse. In the 21st century, of the 87 total lunar eclipses that occur, 28 coincide with a supermoon and 6 coincide with a micromoon, the opposite phenomenon where the Moon is near its farthest point from Earth. A blood moon refers specifically to a total lunar eclipse, defined by Earth’s shadow, while a supermoon refers to a full moon at the Moon’s closest approach to Earth, defined purely by orbital position. They are genuinely different events that simply overlap on occasion.