Lunar eclipse facts for kids
A lunar eclipse is an amazing event in space. It happens when the Moon moves into the shadow of the Earth. This can only happen during a full moon. Lunar eclipses usually happen about twice a year. They can be seen from a much bigger part of the Earth compared to solar eclipses. Lunar eclipses can last for a few hours, but solar eclipses might only last a few minutes.
During a lunar eclipse, the Moon often looks reddish-brown. You might think the Moon would be completely dark because of Earth's shadow. However, the reddish color comes from some of the Sun's light bending through Earth's atmosphere and then bouncing off the Moon.
Just like solar eclipses, there are different kinds of lunar eclipses. A total lunar eclipse is when the Moon passes completely through Earth's darkest shadow. The whole Moon then looks reddish-brown. A partial lunar eclipse is when only part of the Moon goes through Earth's shadow. So, only part of the Moon looks reddish-brown.
It is completely safe to watch lunar eclipses with your eyes. You can also use telescopes to get a closer look!
Contents
What are the Types of Lunar Eclipses?
Earth's shadow has two main parts. These are called the umbra and the penumbra. The umbra is the central, darkest part of the shadow. Here, Earth completely blocks direct sunlight. The penumbra is the outer, lighter part of the shadow. In this area, Earth only partly blocks the sunlight. This is because the Sun looks about one-quarter the size of Earth from the Moon.
A penumbral lunar eclipse happens when the Moon passes through Earth's penumbra. This causes the Moon's surface to look only slightly dimmer. A special kind of penumbral eclipse is a total penumbral lunar eclipse. In this rare event, the Moon is entirely within Earth's penumbra. The part of the Moon closest to the umbra might look a bit darker than the rest.
A partial lunar eclipse happens when only a part of the Moon enters Earth's umbra. A total lunar eclipse happens when the entire Moon enters the umbra. The Moon moves at about 2,300 miles per hour (3,700 km/h). This means a total eclipse can last for almost 107 minutes. However, the total time the Moon is in Earth's shadow can be up to four hours.
The Moon's distance from Earth can change how long an eclipse lasts. When the Moon is farthest from Earth in its orbit (called apogee), it moves the slowest. The size of Earth's umbra does not change much with the Moon's distance. So, a total lunar eclipse that happens when the Moon is near apogee will last longer.
A central lunar eclipse is a total lunar eclipse where the Moon passes right through the center of Earth's shadow. These are quite rare.
What is a Selenelion?
A selenelion (or selenehelion) is a special event. It is when you can see both the Sun and an eclipsed Moon at the same time. This can only happen just before sunset or just after sunrise. At these times, both the Sun and Moon appear just above the horizon on nearly opposite sides of the sky. Because of this, it is also called a horizontal eclipse.
You can see a selenelion from high places during sunrise or sunset. Even though the Moon is in Earth's shadow, you can see both the Sun and the eclipsed Moon. This is because of something called atmospheric refraction. This makes both the Sun and Moon appear higher in the sky than they actually are.
How Dark Can a Lunar Eclipse Be?
The Danjon scale helps us rate how dark a lunar eclipse is. It was created by André Danjon.
- L=0: Very dark eclipse. The Moon is almost invisible, especially in the middle of the eclipse.
- L=1: Dark eclipse. The Moon looks gray or brownish. It is hard to see details.
- L=2: Deep red or rust-colored eclipse. The center of the shadow is very dark, but the outer edge is quite bright.
- L=3: Brick-red eclipse. The shadow usually has a bright or yellow rim.
- L=4: Very bright copper-red or orange eclipse. The shadow looks bluish and has a very bright rim.
Lunar Eclipses vs. Solar Eclipses
People often mix up solar eclipses and lunar eclipses. Both involve the Sun, Earth, and Moon. However, they are very different events.
Why Does the Moon Look Red During an Eclipse?
The Moon does not go completely dark when it passes through Earth's umbra. This is because sunlight bends, or refracts, through Earth's atmosphere into the shadow. If Earth had no atmosphere, the Moon would be totally dark during an eclipse. The reddish color happens because sunlight has to travel through a thick layer of Earth's atmosphere. Here, the light is scattered. Shorter light waves (like blue and violet) are scattered more by air molecules and small particles. This means longer light waves (like red) are the ones that mostly make it through. This is why we see the Moon as red. It is the same effect that makes sunsets and sunrises look reddish. Imagine you are on the Moon. You would see the Sun setting or rising behind Earth, creating a ring of reddish light around Earth.
How much light bends depends on how much dust or clouds are in the atmosphere. The dustier the atmosphere, the more other colors of light are removed. This leaves a deeper red color. This is why the Moon's coppery-red color can look different in each eclipse. Large volcanic eruptions can put a lot of dust into the atmosphere. This can greatly affect the Moon's color during an eclipse that happens soon after.
Lunar Eclipses in Culture and History
Many cultures have myths about lunar eclipses. Some see them as good or bad omens. The ancient Egyptians thought an eclipse was a sow swallowing the Moon for a short time. Other cultures believed the Moon was being eaten by animals. For example, the Mayans thought a jaguar was eating it. In China, some believed a three-legged toad was the culprit. Some societies thought a demon was swallowing the Moon. They would throw stones and shout curses to try and scare it away. The ancient Greeks were very smart. They knew the Earth was round and used the shadow from a lunar eclipse as proof. Some Hindus believe that bathing in the Ganges River after an eclipse helps them achieve salvation.
Incans
Like the Mayans, the Incans believed a jaguar ate the Moon during a lunar eclipse. This is why the Moon looked red, like blood. The Incans also feared that after eating the Moon, the jaguar might come down and eat all the animals on Earth. So, they would use spears and shout at the Moon to keep the jaguar away.
Mesopotamians
The ancient Mesopotamians believed that seven demons attacked the Moon during a lunar eclipse. They thought this attack was also aimed at their king, who represented the land. To protect the true king, they would have someone pretend to be the king. This substitute king would then be attacked instead. After the eclipse, the substitute king would disappear, possibly by poisoning.
Chinese
In some Chinese cultures, people would ring bells during an eclipse. They did this to stop a dragon or other wild animals from biting the Moon. In the 1800s, the Chinese navy even fired its cannons during a lunar eclipse because of this belief. During the Zhou Dynasty, people believed that a red Moon covered in darkness meant famine or disease was coming.
What is a "Blood Moon"?
You might hear the term "blood moon" in popular articles. This is not a scientific term. It has two meanings that are related.
The first meaning is simpler. It refers to the reddish color a totally eclipsed Moon takes on. When sunlight passes through Earth's atmosphere, the air acts like a filter. It bends the light rays. Green to violet light waves are scattered more strongly than red ones. This makes the Moon look reddish.
The second meaning of "blood moon" comes from two Christian pastors, Mark Blitz and John Hagee. They said that a series of four lunar eclipses in 2014–2015 (a "lunar tetrad") matched what the Book of Joel in the Hebrew Bible describes as the "moon turning to blood." These eclipses happened at the same time as the Jewish feasts of Passover and Tabernacles. They claimed this tetrad meant the Second Coming of Christ and the Rapture were near.
How Often Do Lunar Eclipses Happen?
At least two lunar eclipses happen every year. Sometimes, there can be as many as five. However, total lunar eclipses are much less common. If we know the date and time of one eclipse, we can predict future ones using something called an eclipse cycle, like the saros.
Images for kids
-
The total May 2022 lunar eclipse. Direct sunlight is blocked by Earth. The only light reaching the Moon is sunlight bent by Earth's atmosphere, making it look reddish.
-
Later stages of the partial July 2019 lunar eclipse taken from Gloucestershire, United Kingdom.
-
The Moon does not go completely dark during an eclipse. This is because Earth's atmosphere bends sunlight into the shadow.
_(cropped).jpg)
See also
In Spanish: Eclipse lunar para niños
