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Total Solar Eclipse 2024: The Moon\u2019s Moment in the Sun<\/h1>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n![\"This](\"https:\/\/science.nasa.gov\/wp-content\/uploads\/2024\/03\/nasa-moon-eclipse-poster-nguyen-preview.png?w=1472\")
<\/figure>\nArtist\u2019s representation of a total solar eclipse, with a new moon in the foreground and the Sun\u2019s corona visible in the background. Download the Poster<\/div>\nNASA\/Vi Nguyen<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\nOn April 8, 2024, much of North America will experience a solar eclipse<\/a>: a cosmic alignment of Sun, Moon, and Earth, in that order. The Moon\u2019s shadow path will make landfall on Mexico\u2019s Pacific coast, cross the United States from Texas to Maine, and exit North America via Newfoundland, Canada, continuing into the Atlantic Ocean.\u00a0<\/p>\nLearn how to safely observe the 2024 Solar Eclipse<\/strong><\/a><\/p>\nIt\u2019s All About Perspective<\/strong><\/h2>\nSolar eclipses on Earth are a convenient coincidence. The Sun\u2019s diameter is about 400 times larger than the Moon\u2019s, and the Sun is almost 400 times farther away from us than the Moon is. This combination makes the Sun and Moon appear nearly the same size in our sky, setting up a spectacular show when they align. Try experimenting with apparent size for yourself by holding up a small item, like your thumb, and moving it closer and farther away to block different-sized objects from your view.\u00a0<\/p>\n
The Moon\u2019s distance from Earth varies, though only slightly. The Moon\u2019s orbit is not a perfect circle, and it is not quite centered on our planet. At its closest, the Moon is about twenty-eight Earth diameters away; at its farthest, about thirty-two. As a result, the Moon\u2019s apparent size changes over time, and eclipses are not all alike<\/a>.\u00a0<\/p>\nA total solar eclipse is only possible when the Moon is closer to Earth than average. When the Moon is farther away, its apparent size is smaller than the Sun\u2019s, so it does not completely block the Sun\u2019s bright disk. In this configuration, when the Moon passes between Earth and the Sun, a \u201cring of fire\u201d remains visible \u2013 that\u2019s an annular solar e<\/a>clipse<\/a>.<\/p>\nAn Orbital Dance<\/strong><\/h2>\n\n\n<\/div>Video tutorial describing the 2024 total solar eclipse and explaining the Moon\u2019s role in creating it. Credit: NASA\u2019s Goddard Space Flight Center<\/figcaption><\/figure>\nEver wonder why solar eclipses don\u2019t happen more often? Earth, Moon, and Sun don\u2019t line up perfectly every month because the Moon\u2019s orbit is tilted by about 5 degrees compared to Earth\u2019s orbit around the Sun. Most of the time, the Moon\u2019s shadow misses our planet<\/a>.\u00a0<\/p>\nWhen all three celestial bodies do align, views of the eclipse depend not just on our position in the solar system, but also on our location on Earth<\/a>. The Moon\u2019s shadow has two parts, the umbra and the penumbra. Observers in the umbra (or \u201cpath of totality\u201d) will experience a total solar eclipse. For those in the penumbra, the eclipse will be partial.<\/p>\n\n\n\n![\"A](\"https:\/\/science.nasa.gov\/wp-content\/uploads\/2022\/10\/eclipse-map-2024-1920-1.png?w=1920\")
<\/figure>\n2024 Total Solar Eclipse shadow path map, built using datasets from several NASA missions. For more information, visit NASA\u2019s Scientific Visualization Studio: The 2024 Total Solar Eclipse.<\/div>\nNASA\u2019s Scientific Visualization Studio<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\nIf you are planning to observe the eclipse, you\u2019ve probably consulted a shadow path map like this one. But how do we know exactly where and when the Moon will cast its shadow? Eclipse prediction depends, first and foremost, on understanding the positions and movements of the Moon, Sun, and Earth. Modern maps build on a long human history of eclipse forecasting. And since 2009, NASA\u2019s Lunar Reconnaissance Orbiter (LRO) has been mapping the Moon in unprecedented detail. LRO\u2019s lunar topography data enables us to make more accurate eclipse predictions than ever before.<\/p>\n
Moonshadow: The Making of a Map<\/strong><\/h2>\nThe Moon is a rugged world of peaks, craters, basins, and valleys. Since the lunar horizon is bumpy and jagged, the shadow it casts is not quite round<\/a>. Knowing the precise shape of the Moon helps us understand exactly where its shadow will darken Earth\u2019s surface. Of course, our own planet is not perfectly round, either. Today\u2019s eclipse maps<\/a> account not only for the lunar landscape, but also for the contours of Earth\u2019s mountain ranges, lowlands, and other features.<\/p>\n\n\n\n![\"Composite](\"https:\/\/science.nasa.gov\/wp-content\/uploads\/2024\/03\/solareclipsecomposite-sdo-lro.jpg?w=2048\")
<\/figure>\nUneven lunar terrain partially blocks the Sun in this composite image of a partial solar eclipse, showing the Moon (visualization based on Lunar Reconnaissance Orbiter data) passing between Earth and the Sun (as imaged from space by the Solar Dynamics Observatory spacecraft on October 7, 2010).<\/div>\nNASA\u2019s Scientific Visualization Studio<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n Bursts of Light: Baily\u2019s Beads and the Diamond Ring Effect<\/strong><\/h2>\nCasual observers don\u2019t usually notice that the Moon\u2019s silhouette is rough around the edges. At a distance of 239,000 miles (that\u2019s the average gap between Earth and the Moon), our nearest neighbor in space looks round \u2013 even mountains appear too small for the human eye to distinguish. But, for two brief moments during a solar eclipse, craggy lunar terrain commands the spotlight.<\/p>\n
On the brink of totality, as the Moon moves into full Sun-blocking position, the Sun\u2019s edge doesn\u2019t go dark all at once. Last rays of sunlight peek through valleys on the lunar horizon. These isolated areas of intense brightness can resemble a string of glowing beads or a single dramatic burst of light like the gem on a ring. The same phenomena, sometimes called Baily\u2019s Beads and the Diamond Ring Effect, can also occur as the Moon edges out of totality (or annularity). Since we know the shape and position of the Moon so well, we can predict where the first and last bits of sunlight will appear.<\/p>\n
\n\n\n![\"A](\"https:\/\/science.nasa.gov\/wp-content\/uploads\/2023\/07\/5663_Bailys_Beads-1.jpeg?w=1024\")
<\/figure>\nBaily\u2019s Beads as seen during the August 21, 2017 total solar eclipse.<\/div>\nNASA\/Aubrey Gemignani<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\nNASA Eclipse Science and You<\/strong><\/h2>\nNASA scientists take full advantage of the unusual atmospheric and environmental conditions<\/a> the Moon\u2019s passing shadow creates, and you can too. Here are just a few places to start.<\/p>\n\n- Join a community eclipse science project like Eclipse Soundscapes<\/a> or GLOBE Eclipse<\/a>.<\/li>\n
- A solar eclipse is a rare opportunity to directly observe a new moon<\/a>. Document your experience and kick off a month of Moon observations with our special edition Moon Observation Journal<\/a>.\u00a0<\/li>\n
- Learn more about lunar and solar eclipses<\/a>.\u00a0<\/li>\n
- Connect with observers around the world and keep celebrating the Moon\u2019s place in science and culture on the next International Observe the Moon Night<\/a>, Sept. 14, 2024.\u00a0<\/li>\n<\/ul>\n
Science Advisor: Ernie Wright, NASA\u2019s Goddard Space Flight Center<\/em><\/p>\n\n\n\nAbout the Author<\/h3>\n<\/div>\n<\/div>\n\n\n\n![\"Caela](\"https:\/\/secure.gravatar.com\/avatar\/f4ba9d4b54aac7d3b6e41d72ad7fa70a?s=300&d=blank&r=g\")
<\/div>\n\n\nCaela Barry<\/h2>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n<\/div>\n<\/div>\n<\/div>\n
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<\/figure>On April 8, 2024, much of North America will experience a solar eclipse<\/a>: a cosmic alignment of Sun, Moon, and Earth, in that order. The Moon\u2019s shadow path will make landfall on Mexico\u2019s Pacific coast, cross the United States from Texas to Maine, and exit North America via Newfoundland, Canada, continuing into the Atlantic Ocean.\u00a0<\/p>\n Learn how to safely observe the 2024 Solar Eclipse<\/strong><\/a><\/p>\n Solar eclipses on Earth are a convenient coincidence. The Sun\u2019s diameter is about 400 times larger than the Moon\u2019s, and the Sun is almost 400 times farther away from us than the Moon is. This combination makes the Sun and Moon appear nearly the same size in our sky, setting up a spectacular show when they align. Try experimenting with apparent size for yourself by holding up a small item, like your thumb, and moving it closer and farther away to block different-sized objects from your view.\u00a0<\/p>\n The Moon\u2019s distance from Earth varies, though only slightly. The Moon\u2019s orbit is not a perfect circle, and it is not quite centered on our planet. At its closest, the Moon is about twenty-eight Earth diameters away; at its farthest, about thirty-two. As a result, the Moon\u2019s apparent size changes over time, and eclipses are not all alike<\/a>.\u00a0<\/p>\n A total solar eclipse is only possible when the Moon is closer to Earth than average. When the Moon is farther away, its apparent size is smaller than the Sun\u2019s, so it does not completely block the Sun\u2019s bright disk. In this configuration, when the Moon passes between Earth and the Sun, a \u201cring of fire\u201d remains visible \u2013 that\u2019s an annular solar e<\/a>clipse<\/a>.<\/p>\n Ever wonder why solar eclipses don\u2019t happen more often? Earth, Moon, and Sun don\u2019t line up perfectly every month because the Moon\u2019s orbit is tilted by about 5 degrees compared to Earth\u2019s orbit around the Sun. Most of the time, the Moon\u2019s shadow misses our planet<\/a>.\u00a0<\/p>\n When all three celestial bodies do align, views of the eclipse depend not just on our position in the solar system, but also on our location on Earth<\/a>. The Moon\u2019s shadow has two parts, the umbra and the penumbra. Observers in the umbra (or \u201cpath of totality\u201d) will experience a total solar eclipse. For those in the penumbra, the eclipse will be partial.<\/p>\n If you are planning to observe the eclipse, you\u2019ve probably consulted a shadow path map like this one. But how do we know exactly where and when the Moon will cast its shadow? Eclipse prediction depends, first and foremost, on understanding the positions and movements of the Moon, Sun, and Earth. Modern maps build on a long human history of eclipse forecasting. And since 2009, NASA\u2019s Lunar Reconnaissance Orbiter (LRO) has been mapping the Moon in unprecedented detail. LRO\u2019s lunar topography data enables us to make more accurate eclipse predictions than ever before.<\/p>\n The Moon is a rugged world of peaks, craters, basins, and valleys. Since the lunar horizon is bumpy and jagged, the shadow it casts is not quite round<\/a>. Knowing the precise shape of the Moon helps us understand exactly where its shadow will darken Earth\u2019s surface. Of course, our own planet is not perfectly round, either. Today\u2019s eclipse maps<\/a> account not only for the lunar landscape, but also for the contours of Earth\u2019s mountain ranges, lowlands, and other features.<\/p>\n Casual observers don\u2019t usually notice that the Moon\u2019s silhouette is rough around the edges. At a distance of 239,000 miles (that\u2019s the average gap between Earth and the Moon), our nearest neighbor in space looks round \u2013 even mountains appear too small for the human eye to distinguish. But, for two brief moments during a solar eclipse, craggy lunar terrain commands the spotlight.<\/p>\n On the brink of totality, as the Moon moves into full Sun-blocking position, the Sun\u2019s edge doesn\u2019t go dark all at once. Last rays of sunlight peek through valleys on the lunar horizon. These isolated areas of intense brightness can resemble a string of glowing beads or a single dramatic burst of light like the gem on a ring. The same phenomena, sometimes called Baily\u2019s Beads and the Diamond Ring Effect, can also occur as the Moon edges out of totality (or annularity). Since we know the shape and position of the Moon so well, we can predict where the first and last bits of sunlight will appear.<\/p>\n NASA scientists take full advantage of the unusual atmospheric and environmental conditions<\/a> the Moon\u2019s passing shadow creates, and you can too. Here are just a few places to start.<\/p>\n Science Advisor: Ernie Wright, NASA\u2019s Goddard Space Flight Center<\/em><\/p>\n \n<\/div>\n<\/div>\n<\/div>\nIt\u2019s All About Perspective<\/strong><\/h2>\n
An Orbital Dance<\/strong><\/h2>\n
<\/figure>Moonshadow: The Making of a Map<\/strong><\/h2>\n
<\/figure> Bursts of Light: Baily\u2019s Beads and the Diamond Ring Effect<\/strong><\/h2>\n
<\/figure>NASA Eclipse Science and You<\/strong><\/h2>\n
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About the Author<\/h3>\n<\/div>\n<\/div>\n
Caela Barry<\/h2>\n<\/div>\n
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