What is a lunar eclipse?
During a lunar eclipse, the Earth blocks most of the sunlight that normally reaches the Moon. The Earth is between the Sun and the Moon.
This is different from a solar eclipse, when the Moon passes between the Sun and Earth and blocks all or part of the Sun. In a solar eclipse, the Sun gets darker; in a lunar eclipse, the Moon gets darker. Visit our solar eclipse page to learn more.
Upcoming lunar eclipses
https://www.timeanddate.com/eclipse/
Watch this NASA video to learn more about the different roles of the Moon in lunar and solar eclipses.
2021 Lunar Eclipses: May 25-26, 2021 and November 18-19, 2021
Who Can See It
Lots of people! People in the contiguous United States, Alaska, and Hawaii will see two lunar eclipse events this year—but not everyone will see a total lunar eclipse.
Where and When Can You See It?
There are several websites to check to confirm if an when your location can view the total lunar eclipse on May 26th, 2021 and the partial lunar eclipse on Nov 19, 2021.
May 25-26, 2021
- TimeandDate.com has a helpful interactive to search for your location to determine start and end time of the upcoming lunar eclipses:
Eclipse Map — May 26, 2021 Total Lunar Eclipse - NASA has created PDFs that summarize the location where the lunar eclipses will be visible here:
Total Lunar Eclipse of May 26th, 2021 - Video of the May 25-26, 2021 Lunar Eclipse from Hawaii:
https://www.youtube.com/watch?v=_P_L7E7-CIE&t=4828s
https://sites.google.com/view/lunareclipse
November 18-19, 2021
- TimeandDate.com has a helpful interactive to search for your location to determine start and end time of the upcoming lunar eclipses:
Eclipse Map — November 18–19, 2021 Partial Lunar Eclipse - NASA has created PDFs that summarize the location where the lunar eclipses will be visible here:
Partial Lunar Eclipse of Nov 19th, 2021
Advice for Viewing
If skies are clear, the eclipse will be visible to the unaided eye. It is safe to view a lunar eclipse without any eye protection.
More viewing tips an information about lunar eclipses from the May 2021 Skywatching Tips from NASA
Why Does the Moon Turn Red?
The Moon does not completely darken in the Earth's shadow during a lunar eclipse. Sunlight on the edges is scattered by the Earth's atmosphere, only allowing red light through to the Moon. This red light is reflected back to viewers on Earth who can see the lunar eclipse.
Watch this NASA video to see why the Moon turns red during a lunar eclipse.
Additional Lunar Eclipse Resources
- Understanding Lunar Eclipses video
https://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=11516 - Lunar phases and eclipses from NASA Science Solar System Exploration
https://solarsystem.nasa.gov/moons/earths-moon/lunar-phases-and-eclipses/ - What would Earth look like from the Moon during a lunar eclipse?
https://svs.gsfc.nasa.gov/4157 - Teachable Moment: How to Watch a Total Lunar Eclipse and Get Students Observing the Moon
https://www.jpl.nasa.gov/edu/news/2018/1/18/how-to-watch-a-total-lunar-eclipse-and-get-students-observing-the-moon/ - Teachable Moment: What’s a Supermoon and Just How Super Is It?
https://www.jpl.nasa.gov/edu/news/2017/11/15/whats-a-supermoon-and-just-how-super-is-it/ - What science can be done during a lunar eclipse?
https://www.nasa.gov/feature/goddard/2018/what-scientists-can-learn-about-the-moon-during-the-jan-31-eclipse - Lunar eclipses until 2030
https://eclipse.gsfc.nasa.gov/LEdecade/LEdecade2021.html
Related NISE Network Moon Activities
- Exploring Earth: Bear’s Shadow early childhood activity (included in the Explore Science: Earth & Space 2017 and 2020 toolkit)
https://www.nisenet.org/catalog/exploring-earth-bears-shadow - Exploring the Solar System: Big Sun, Small Moon activity (included in the Explore Science: Earth & Space 2017 toolkit)
http://www.nisenet.org/catalog/exploring-solar-system-big-sun-small-moon - Exploring the Solar System: Solar Eclipse activity (included in the Explore Science: Earth & Space 2017 toolkit)
http://www.nisenet.org/catalog/exploring-solar-system-solar-eclipse - Exploring the Solar System: Craters activity (included in the Explore Science: Earth & Space 2018 and 2020 toolkit)
http://www.nisenet.org/catalog/exploring-solar-system-craters-2018 - Exploring the Solar System: Hide and Seek Moon early childhood activity (included in the Explore Science: Earth & Space 2018 and 2019 toolkit)
http://www.nisenet.org/catalog/exploring-solar-system-hide-and-seek-moon-2018 - Exploring the Solar System: Moonquakes activity (included in the Explore Science: Earth & Space 2020 toolkit)
https://www.nisenet.org/catalog/moonquakes - Exploring the Solar System: Story Blocks activity (included in the Explore Science: Earth & Space 2020 toolkit)
https://www.nisenet.org/catalog/moon-story-blocks - Exploring the Solar System: Observe the Moon activity (included in the Explore Science: Earth & Space 2020 toolkit)
https://www.nisenet.org/catalog/observing-the-moon - Moon Adventure Game
https://www.nisenet.org/moongame
Related NASA Educator Guides and Activities
- Classroom Activity: Evaluating a Lunar Eclipse
https://www.jpl.nasa.gov/edu/teach/activity/evaluating-a-lunar-eclipse/ - Classroom Activity: Measuring the Supermoon
https://www.jpl.nasa.gov/edu/teach/activity/measuring-the-supermoon/ - Classroom Activity: When Do Lunar Eclipses Happen?
https://www.jpl.nasa.gov/edu/teach/activity/when-do-lunar-eclipses-happen/ - Student Activity: When Do Lunar Eclipses Happen?
https://www.jpl.nasa.gov/edu/learn/project/when-do-lunar-eclipses-happen/
Compilation of Moon Resources including Artemis and Apollo Missions