Lunar eclipses occur when Earth's shadow blocks sunlight that would otherwise be reflected by the moon. There are three types: total, partial, and penumbral. Learn more about lunar eclipses here and why eclipses happen.
What is a Lunar Eclipse?
The lunar eclipse is an astronomical phenomenon that occurs when the shadow of the Earth obscures the moon. In fact, the Earth makes a rotation movement around the Sun, called a revolution, the side of the Earth facing the Sun is hit by sunlight, while on the opposite side the Earth casts a shadow cone in space.
The Moon, in turn, revolves around the Earth, so it can pass totally or partially into this shadow cone. If this happens, we witness a lunar eclipse . This event occurs on average twice a year. Additionally, a wider penumbra cone extends around the Earth's shadow cone, through which some sunlight penetrates. You can learn more about astronomy for children to understand this phenomenon.
The phenomenon can last for almost four hours. As it darkens, the moon often takes on various shades. The so-called red moon is particularly fascinating. This occurs due to the optical phenomenon of sunlight refraction; in fact, Earth's atmosphere deflects some of the sun's light—the red light—into its own shadow. You can learn more about the blood moon here to find out more about this phenomenon.
For this reason, when the Moon enters the Earth's shadow cone, it is enveloped in a reddish haze. A total eclipse occurs only when the alignment between the Sun, Earth, and Moon is perfect. You can research the Worm Moon further if you are interested in other types of moons.
However, if the alignment is not perfect, one part of the Moon falls into the cone of shadow while the other falls into the cone of twilight: in this case, only one part of the Moon is completely dark and the other, for other side, is slightly veiled from twilight.
Steps
For a Lunar Eclipse to occur, several stages are required:
The moon enters the penumbra: the Earth's shadow cone has two parts: a dark inner umbra, surrounded by a lighter penumbra; the penumbra is the pale outer portion of the Earth's shadow.
Although the eclipse officially begins at the moment the Earth enters the penumbra, this is a correct event. Nothing unusual will be observed to happen to the moon, at least not yet.
The moon enters the umbra: The moon now moves through the Earth's dark central shadow, called the umbra. A small dark band appears on the lower left (southeast) side of the moon; the partial phases of the eclipse begin; the pace quickens and the change is dramatic.
The umbra is much darker than the penumbra and has quite sharp edges. As the minutes pass, the dark shadow appears to creep slowly across the face of the Moon.
At first, the limb of the moon may appear to fade completely into the umbra, but much later, as the moon moves deeper, you'll probably notice it glowing orange, red, or brown. .
The total eclipse begins: when the last part of the moon enters the umbra, the total eclipse begins. It's impossible to know what the moon will look like during totality. Some eclipses are a dark gray-black color, so dark that the moon almost disappears from view; in other eclipses, the moon may shine with a bright orange color.
For an astronaut standing on the moon during totality, the sun would be hidden behind a dark Earth, outlined by a bright red ring made up of all the sunrises and sunsets on Earth. The way light is scattered is also an interesting phenomenon that you can explore further in the actual shape of the Earth.
The brightness of this ring around the Earth depends on global weather conditions and the amount of dust suspended in the air, a clear atmosphere on Earth means a bright lunar eclipse.
Mid-totality: The moon is now between 10.000 and 100.000 times fainter than it was just a couple of hours before. As the moon moves north of the center of Earth's umbra, the gradation of color and brightness on the moon's disk should make its lower portion appear darker, with shades of deep copper or chocolate brown.
The total eclipse ends: the moon begins to emerge from the shadow, the first small segment of the moon reappears, followed again for the next few minutes by the Japanese lantern effect.
The moon leaves the umbra: the dark central shadow clears the right (western) limb of the moon.
Penumbra's shadow fades: as the last faint shadow fades from the right portion of the moon, the visual spectacle comes to an end.
The moon leaves the penumbra: the eclipse officially ends, as the moon is completely free of the penumbral shadow.
How does a Lunar Eclipse occur?
A total lunar eclipse occurs when the Moon passes completely through the Earth's umbra. The Moon dims as it enters twilight and then darkens further as it passes through the umbra. Later, it gradually regains its brightness as it emerges first from the umbra and then from the penumbra. For more details about this phenomenon, you can explore Norse myths about the moon.
The name refers to the gradual darkening of stars during an eclipse, and it has been a subject of study since antiquity: the Maya and the ancient Greeks were able to predict them as early as the 5th century BC. Furthermore, the profile of the Earth's shadow on the Moon during eclipses is one of the earliest indications that the Earth is spherical. You can learn more about Mayan astronomy related to eclipses.
When there is?
This type of eclipse is visible from all locations on Earth where the Moon is above the horizon, and it occurs approximately four to five times a year. More information about specific dates can be found in the eclipse classes.
This occurs because, due to the effect of the Earth's atmosphere, the sun's rays are partly diffused and partly refracted into the shadow cone and are not completely shielded.
Types of Lunar Eclipse
There are three types of Lunar Eclipse, which are mentioned below:
penumbral
Penumbral lunar eclipses are very subtle and can sometimes go unnoticed depending on how deep they enter the penumbra. During these eclipses, the Moon only grazes the Earth's outer shadow.
Of course, these are witnesses to the early stages of a partial or total lunar eclipse, but sometimes penumbral lunar eclipses occur. A slight darkening of one side of the full moon is seen, which then slowly progresses around the edge of the moon before a full moon is re-established. The impact of these eclipses has been studied throughout the history of night sky guides.
Part Time
Partial lunar eclipses can be seen during the build up to a total lunar eclipse or when there is an eclipse of the Moon which will only be partial, the Moon enters the penumbra and then part of the Earth's primary shadow called the umbra, but this shadow does not cover completely the moon.
There is an illustration of these two shadows further down the page. Only the Earth's outer shadow (the penumbra) covers the entire Moon, making the full moon appear dimmer. The side of the Moon in the umbra will darken considerably, as shown in the image above. Those interested can continue reading about related astronomical phenomena .
Total
In a total lunar eclipse, also called a blood moon, the earth's shadow falls on the moon, this can be seen in the sky as a coppery red, dark yellow or brown disk.
Although the moon itself is a dark object, it can be observed from Earth because it is illuminated by the sun. During a total lunar eclipse, the Earth moves between the sun and the moon, so direct sunlight no longer reaches the moon's surface. As mentioned earlier, you can learn more about the moon as a satellite and its influence on astronomical events.
The Eclipse of the year 1504
While Christopher Columbus was examining an almanac containing astronomical charts covering solar and lunar eclipses from 1475 to 1506, he noted that a total lunar eclipse was due shortly, on the night of February 29, 1504.
So Columbus arranged a meeting with the chief of the Arawaks and told him that the Christian God was angry with the natives for not feeding Columbus and his men.
He informed the natives that their God would demonstrate his wrath within three nights by turning the moon blood red and then erasing it as a portent of coming calamities. The Arawaks mocked this until the appointed night when Columbus's prediction came true and the moon turned red, then began to disappear.
The moon gradually reappeared just as Columbus finished speaking and from then on the Arawak leaned back to help and kept Columbus and his crew supplied and well fed.
The castaways spent leisurely time during the remainder of their stay in Jamaica, until rescue ships arrived to haul them off the island months later.
Solar and lunar eclipses in culture
Ancient peoples tracked how lunar and solar cycles intersected, and they also discovered some of the factors that lead to lunar and solar eclipses, which require specific times of the sun's and moon's positions across the sky over the years. The relationship between these phenomena and Mayan culture is particularly interesting.
In many ways, the ability to predict eclipses was an outgrowth of the pre-existing need to keep track of lunar and solar calendar relationships.
ancient China
Observing total solar eclipses was an important element in forecasting future health. The Emperor's successes and astrologers were left with the onerous task of trying to anticipate when these events might occur. If the prediction is not done well, in at least one recorded case in the year 2300 a. C., resulted in the beheading of two astrologers.
Babylon and Sumer
Like the Chinese, Babylonian astrologers kept careful records of celestial events, including the movements of Mercury, Venus, the Sun, and the Moon, on tablets dating from 1700 to 1681 BC. Later records identified a total solar eclipse on July 31, 1063 BC.
Ancient Greece
Lunar eclipses were especially easy to calculate due to the vast area covered by Earth's structure on the Moon. However, solar eclipses required much greater knowledge; the Moon's shadow on Earth is less than 100 kilometers wide.
The Maya
The Maya were working on calendars and recording celestial observations. The Dresden Codex records several tables that are considered lunar eclipse tables. As with earlier civilizations elsewhere in the world, the Maya used records of historical lunar eclipses to calculate their frequency over a 405-month period.
