There are lunar eclipses when the sun and moon are aligned. According to the European Space Agency, a lunar eclipse can last as long as six hours.

There are three types of lunar eclipses depending on how the sun, Earth and moon are aligned.

  1. Total lunar eclipse 
  2. Partial lunar eclipse 
  3. Penumbral lunar eclipse 

There will be two total lunar eclipses in 2022. The first and second lunar eclipses will take place in May and November. To find out when, where and how to see this year's lunar eclipses, check out our lunar eclipse guide.

How to photograph a lunar eclipse.

What are lunar eclipses?

Earth blocking sunlight from reaching the moon causes a lunar eclipse. During a lunar eclipse, the umbra is a full shadow and the penumbra is a partial shadow.

lunar eclipse diagram showing show Earth casts a shadow across the lunar surface.

During a lunar eclipse the sun, Earth and moon align so that Earth blocks sunlight from reaching the moon and casts a shadow across the lunar surface. Whether the moon sits in the penumbra or umbra will dictate the type of lunar eclipse. During a total lunar eclipse, the umbra completely covers the lunar surface. In this diagram, the moon is located in the penumbral shadow so it is experiencing a penumbral eclipse. (Image credit: Future)

A total lunar eclipse has seven stages.

  1. Penumbral eclipse begins: This first stage is not that noticeable to the naked eye and occurs when the penumbral shadow begins to move across the moon. 
  2. Partial eclipse begins: The umbra begins to cover the moon. This is usually the first part of the eclipse visible to the naked eye.  
  3. Total eclipse begins: As the umbra completely covers the lunar surface, the moon turns a blood-red color. 
  4. Maximum eclipse: This is the stage of the eclipse with maximum coverage of the lunar surface by Earth's umbra.  
  5. Total eclipse ends: Earth's umbra begins to move away from the lunar surface as the eclipse begins to wrap up.  
  6. Partial eclipse ends: Earth's umbra leaves the lunar surface. 
  7. Penumbral eclipse ends: Earth's shadow is no longer cast across the lunar surface.  

A partial lunar eclipse may look like it is taking a bite out of the lunar surface. On the side of the moon facing Earth, there will be a dark shadow. How much of a bite we see depends on how the sun, Earth and moon align, according to NASA.

Why is the moon red during an eclipse?

red moon during a lunar eclipse

The moon turned blood-red over the Sossusvlei Desert Lodge on NamibRand Nature Reserve in Namibia in this stunning photo taken by skywatcher George Tucker on June 15, 2011. (Image credit: George Tucker)

During a total lunar eclipse, the lunar surface turns a rusty red color.

The eerie red appearance is caused by sunlight interacting with Earth.

Our atmosphere scatters and filters the sun's light. The Natural History Museum says that blue light is scattered outward while red light is bent into the umbra. When the moon passes through Earth's umbra during a total lunar eclipse, the red light reflects off the lunar surface, giving the moon its blood-red appearance.

NASA scientists say how gold, orange, or red the moon appears during a total lunar eclipse depends on how much dust, water, and other particles are in Earth's atmosphere. The appearance of the moon during a lunar eclipse is influenced by other atmospheric factors.

How often do lunar eclipses occur?

According to the National History Museum, there are about three lunar eclipses a year. According to TimeandDate.com, 29% of lunar eclipses are total lunar eclipses.

Solar eclipses are more difficult to observe than lunar eclipses, as they can be seen by anyone who can see the moon above the horizon. On average, a total eclipse can be seen from any given location once every 2.5 years.

How to watch a lunar eclipse

montage of lunar eclipse phases.

This montage of images taken by skywatcher Keith Burns shows the Dec. 20, 2010 total lunar eclipse. The photos won a NASA contest to become an official NASA/JPL wallpaper for the public. (Image credit: NASA/JPL-via Kieth Burns)

Skywatching events such as lunar eclipses are easy to observe.

You can simply look up and enjoy watching one. You do not need a telescope or any other special equipment. During an eclipse, moonwatching is as interesting as it is at any other time. An eclipse can take a couple of hours to unfold, so if you plan to be out for the duration, you should bundle up. Bring warm drinks and blankets.

Scientists like to watch lunar eclipses.

We can get good science out of what happens to the surface of the moon during lunar eclipses, but the cool thing is that the moon changes color. It is always exciting when we see a change in the skies.

If you want to take a photo of the moon during a lunar eclipse, we have a guide for you. The best cameras for Astrophotography and best lenses for Astrophotography have recommendations to make sure you are ready for the next eclipse.

lunar eclipse from the surface of the moon.

The Earth blocks the sun during a total lunar eclipse, as seen from the moon. (Image credit: NASA)

Additional resources

NASA Science has more about lunar phases and eclipses. Hanwell Community Observatory has a fact sheet on lunar eclipse information. We don't have a lunar eclipse every month because of the Rice Space Institute.

Bibliography

NASA. There was a total lunar eclipse. NASA. May 10, 2022.

J. O'Callaghan was published on July 16. There is a guide to the lunar eclipse. There is a museum about natural history. May 10, 2022.

May 3, 2017: NASA. What is an Eclipse? NASA. May 10, 2022.

The total lunar eclipse is on. May 10, 2022.