Total Lunar Eclipse

Total lunar eclipses are among the most spectacular events we can witness on Earth. Total lunar eclipses occur when the Earth is situated between the Sun and the Moon, and thus it covers the Moon with its shadow. This can only happen when the Moon is full.

Occasionally, the Moon might turn red, but that’s nothing to fear since it’s all related to Earth’s atmosphere. One factor, among others, which contributes to the Moon’s reddish hue, is the level of pollution in Earth’s atmosphere.

With that being said, let’s learn some more interesting facts about total lunar eclipses, like how often do they occur, and when the next one will be. Read on, and enjoy!

How Often is a Total Lunar Eclipse?

A total lunar eclipse is a rare event that happens once every 2.5 years or so. They are among the rarest type of eclipse we can witness on Earth, and we can see them from any given location.

Around 35% of lunar eclipses are thus total lunar eclipses. Major lunar eclipses are either total or partial. When it comes to solar eclipses, they are categorized as total, partial, annual, or hybrid.

The difference between a solar and a lunar eclipse is that when we experience a lunar eclipse, the Earth is passing in between the Moon and the Sun.  It’s the opposite during a solar eclipse, as the Moon passes in between the Earth and the Sun, blocking the Sun from view.

When was the Last Total Lunar Eclipse?

Total lunar eclipses are quite rare, but the last total lunar eclipse we have experienced since 2020, was on January 20, 2019. This was the 18th total lunar eclipse since 2001.

In the 21st century, researchers have estimated that we will witness around 85 total lunar eclipses. But that’s not all. We will also witness 87 penumbral eclipses and around 58 partial eclipses. As such, there will be around 230 lunar eclipses in the 21st century.

How does Total Lunar Eclipse Work?

When the Earth is situated between the Sun and the Moon, it blocks enough sunlight to form a shadow on the Moon, resulting in an eclipse. 

The lunar nodes are the two points where the Moon’s orbital path crosses the ecliptic, the Sun’s apparent path on the celestial sphere. Based on how close the Full Moon is to one of these points, Earth’s shadow is larger or smaller, covering the Moon. 

Depending on the size of the shadow, it also affects the duration of a lunar eclipse. As such, there are three types of lunar eclipses:

  • Total lunar eclipse
  • Partial lunar eclipse
  • Penumbral lunar eclipse

The total lunar eclipse is the most significant of these three since Earth’s shadow completely covers the Moon. This is known as the umbra. When it comes to a partial lunar eclipse, the inner part of Earth’s shadow, the umbra, veils only a fraction of the Moon.

In the third case, during a penumbral lunar eclipse, only the diffuse part of Earth’s shadow, which is called the penumbra, falls on the Moon’s surface.

The penumbral lunar eclipse is the most subtle out of all the three types of lunar eclipses. It is much more difficult to observe than a total lunar eclipse or a partial lunar eclipse. 

Don’t forget though; total lunar eclipses occur only when the Moon is full. The scientific term for this event is called syzygy. This term comes from Greek, and it translates to “being paired together.”

The Moon doesn’t have its own light, and as such, it only shines because it reflects the Sun’s rays. The Earth darkens the Moon through its shadow since it blocks sunlight, but the interesting part is that Earth’s shadow is divided into three parts:

  • Umbra
  • Penumbra
  • Antumbra

The umbra is the darkest and central part of Earth’s shadow, while the penumbra is the outer part, and the antumbra is the partly shaded area beyond the umbra.

For a total lunar eclipse to happen, the Sun, Earth, and Moon need to be perfectly aligned. When they come together on a straight line, Earth’s umbra completely covers the Moon.

If these celestial bodies aren’t aligned, but Earth’s penumbra partly covers the Moon, then a partial lunar eclipse occurs. However, if only the outer part of Earth’s shadow covers the Moon, then a penumbral lunar eclipse occurs. Since Earth’s shadow extends far beyond the orbit of the Moon into space, the antumbra plays no role in lunar eclipses.

Why Does the Moon Appear Red During an Eclipse?

Even though Earth blocks the sunlight from reaching the Moon, a bit of light is reflected towards the Moon during sunrises and sunsets. When light waves are stretched out, they appear red.

How red the Moon appears to be depends on certain factors such as pollution, cloud cover, or debris located in Earth’s atmosphere. Sometimes, volcanic eruptions occur, and during these events, particles are released in the atmosphere, which may make the Moon appear darker than usual.

When the Moon appears red during a total lunar eclipse, it is called a Blood Moon; however, something even greater can happen. It is known as a Super Blood Wolf Moon.

A Super Blood Moon is quite a rarity since a special set of circumstances must be completed. For example, the Moon needs to be in its Blood Moon phase, and it needs to be closer to Earth than usual.

When a Full Moon happens during the Moon’s closest point to Earth, we call it a Supermoon, as it appears bigger and brighter than normal.

How Many Lunar Eclipses will there be in 2020?

In 2020, we will experience four lunar eclipses and two solar eclipses. The first lunar eclipse in 2020 was a penumbral lunar eclipse, which occurred on January 10, and it lasted until the 11th.

All the lunar eclipses of 2020 are, in fact, penumbral lunar eclipses. The second occurred on June 5, the third on July 4, while the fourth will happen on November 29, 2020, and it will last until the 30th.

The last lunar eclipse of 2020 can be seen from Europe, parts of Asia, Australia, North America, South America, the Pacific, Atlantic, and the Arctic.

However, the most notable eclipse of 2020 will be a total solar eclipse, which will occur on December 14. It won’t last long, and it will be visible from South Africa, South America, Pacific, Atlantic, Indian Ocean, and Antarctica.

When is the next Total Lunar Eclipse?

In 2021 we will experience a total lunar eclipse on May 26. It will be visible from South/East Asia, Australia, North America, South America, Pacific, Atlantic, Indian Ocean, and Antarctica.

The next total lunar eclipse will then happen on 15-16 May 2022. It will be visible in South/West Europe, South/West Asia, Africa, North America, South America, Pacific, Atlantic, Indian Ocean, and Antarctica.

The year 2022 will be quite spectacular since another total lunar eclipse will occur on November 8. It will be visible from North/East Europe, Asia, Australia, North & South America, Pacific, Atlantic, Indian Ocean, and Antarctica.

From 2022 things will settle down regarding total lunar eclipses; however, things will change in 2025. In 2025, we will experience two more total lunar eclipses. The first one will occur on 14-15 March, while the second one 7-8 September 2025. They will be visible through much of the globe.

Did you Know?

  • Blood Moons caused fear in ancient times, and rightfully so. For example, Columbus knew when the next Blood Moon would occur and used this to his advantage to scare some native Jamaicans into giving him and his screw food supplies.
  • Many apocalyptic prophecies are associated with the Blood Moon.
  • A total lunar eclipse can last up to an hour and three quarters. Solar eclipses are much shorter, and they can last up to seven minutes.
  • Total lunar eclipses, unlike total solar eclipses, are safe to watch with the naked eye.


  1. Timeanddate
  2. Wikipedia
  3. Space
  4. NHM
  5. RMG
  6. NASA

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