May 5, 2023, lunar eclipse will be a subtle show of astronomical wonder

A lunar eclipse occurs when the Earth passes between the Sun and the Moon and throws a portion of its shadow on the Moon. The next lunar eclipse will occur on May 5, 2023.

Africa, Asia, Australia, and significant areas of Europe will be able to see the eclipse, but not this time in the United States. Since the eclipse won't cause a "blood moon," as some refer to it, it is not one. Instead, as it passes through a lighter region of the Earth's shadow known as the penumbra, the Moon will slightly dim.

As the Abrams Planetarium's director at Michigan State University, it is part of my responsibility to encourage people to look up and outside, and eclipses are among the most straightforward celestial events to see. Even though the upcoming event won't be the most breathtaking celestial spectacle, it is only the first of several eclipses that will happen over the course of the following year, and they all function similarly.

Why do eclipses happen?

Eclipses of the moon and sun are dependent on certain alignments of the earth, sun, and moon. When the Moon is completely or partially hidden by the Earth's shadow, a lunar eclipse occurs. Only when the Moon is completely opposite the Sun from the Earth, which happens during full moons, does this occur.

The Sun always shines on half of the Moon, just like on Earth. People on Earth may view the complete lit-up side of the Moon, which appears as a circular disc in the night sky, when the Moon and Sun are exactly opposite one another.

Every full moon would be a lunar eclipse if the Moon's orbit were perfectly flat. But in contrast to Earth's orbit around the Sun, the Moon's orbit is tilted by about 5 degrees. Due to this slight tilt, a full moon typically lies just above or just below the Earth's shadow.

However, the Moon passes through the same horizontal plane as the Earth and the Sun twice during each 30-day lunar orbit. A lunar eclipse would arise if the Sun, Earth, and Moon formed a straight line and the Moon passed into the Earth's shadow during a full moon.

The cast of the EarthEarth casts a shadow behind itself as the Sun illuminates it. However, shadows don't always have a consistent level of darkness, and the Earth's shadow is no exception.

The light beams from a broad, or extended, light source, like the Sun or a flashlight, don't all originate in the same place. Because of how big the Sun is, light beams that are directed toward Earth may originate from locations that are considerably apart.

Due to the Earth's different distance from the Sun, it is possible that Earth does not completely block off light emanating from all of the Sun. As a result, certain areas of the shadow cast by the Earth are darker than others. The darker areas are those where all light is blocked, while the brighter areas are those where some light still escapes the Earth.

A total lunar eclipse occurs when the Moon completely traverses the umbra, or deepest region, of the shadow cast by the Earth. A partial lunar eclipse occurs when the Moon is partially engulfed by the umbra. It is called as a penumbral lunar eclipse because the eclipse on May 5, 2023, will be the last of its kind to cover the Moon entirely with light-colored shadow.

How can the lunar eclipse be seen?

A lunar eclipse may be seen as long as you are on the night side of the planet when it occurs. Most of Europe and Africa will be able to see the penumbral eclipse on May 5 at moonrise; Asia and Australia will be able to see the entire event in the middle of the night; and locations all over the Pacific Ocean will be able to see it at moonset.

Lunar eclipses only last a few hours from beginning to end, making them comparatively brief events. Depending on how near you are to the center of the shadow, totality—the darkest portion of the eclipse—can last anywhere from 30 to 60 minutes.

There will be a ton more in the coming years for folks in North and South America where they won't be able to see the eclipse. The following lunar eclipse, which will be partial, will occur on October 28, 2023, and will be visible predominantly in Africa, Europe, and Asia. However, on March 25, 2024, the Americas will experience their own penumbral eclipse, which will be followed by a partial lunar eclipse on September 18, 2024.

On March 14, 2025, a complete lunar eclipse will be visible from the Americas, western Europe, and western Africa. Those seeking to see it will have to wait until then.