2017 Eclipse: Earth, Moon and Sun
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- Visualizations by:
- Ernie Wright
- View full credits
A solar eclipse occurs when the Moon passes between the Sun and the Earth, casting its shadow on the Earth. The shadow comprises two concentric cones called the umbra and the penumbra. Observers on the Earth who are within the smaller, central umbra see the Sun completely blocked. Within the larger penumbra, the Sun is only partially blocked.
In this animation, the Earth, Moon, Sun, and shadow cones are viewed through a telescopic lens on a virtual camera located far behind the Earth. Long focal lengths like the one used here appear to compress the distance between near and far objects. Despite appearances, the geometry of the scene is correct. The Moon's umbra cone is roughly 30 Earth diameters long, barely enough to reach the Earth, while the Sun is almost 400 times farther away.
From this perspective, we see the night sides of both the Earth and the Moon. Solar eclipses can only occur during New Moon, when the entire Earth-facing side of the Moon is experiencing nighttime darkness.
Credits
Please give credit for this item to:
NASA's Scientific Visualization Studio
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Visualizer
- Ernie Wright (USRA) [Lead]
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Producer
- Kayvon Sharghi (USRA)
Series
This visualization can be found in the following series:Datasets used in this visualization
DE421 (A.K.A. JPL DE421)
Planetary ephemerides
Dataset can be found at: http://ssd.jpl.nasa.gov/?ephemerides#planets
See more visualizations using this data setNote: While we identify the data sets used in these visualizations, we do not store any further details, nor the data sets themselves on our site.
Related pages
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ID: 12678 B-Roll
Eclipse Watching B-Roll At NASA Goddard
Read moreB-roll for August 21st Eclipse, filmed at NASA'S Goddard Space Flight Center's mall and visitor center. || On Monday, Aug. 21, all of North America was treated to one of the rarest celestial events – a solar eclipse. Members of the public came out to NASA’s Goddard Space Flight Center’s Visitors Center to experience the partial and chat NASA scientists about this unique event.During the eclipse, 14 states across the U.S. were in the path of totality and experienced more than two minutes of darkness in the middle of the day – with a partial eclipse viewable all across North America. The eclipse’s long path over land provided a unique opportunity to study the Sun, Earth, Moon and their interaction.Solar eclipses happen somewhere in the world about every 18 months, but much of the time it happens over the ocean. To have an eclipse travel across so much land where millions of people live is incredibly rare, and makes for a unique opportunity for so many to witness one of nature’s most impressive shows.Still images from Earth and science satellites will be uploaded/available at https://flic.kr/s/aHsm21Mytv.Images sent in by the general public will be uploaded/available at https://www.flickr.com/groups/nasa-eclipse2017/. ||
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ID: 12565 Produced Video
Are You Ready for the Eclipse? (Live Interviews on Aug. 16, 2017)
Read moreCanned interviews and b-roll will be available here starting Tuesday, August 15, at 6:00 p.m. ET. || Are you ready for the historic solar eclipse that’s just days away?Do you have what you need to see it safely?You can see the eclipse no matter where you are in North America on Aug. 21!August 21 will be a day for the history books. No matter where you are in North America, you’ll get to experience the first coast-to-coast solar eclipse in nearly a century! The dark shadow of the moon will sweep from Oregon to South Carolina, putting 14 states in the path of totality and providing a spectacular view of a partial eclipse across all 50 states.Eclipses are an incredible experience, but it’s important to view them safely. Join NASA scientists on Wednesday, August 16, from 6:00 a.m. – 12:30 p.m. ET and again from 3:00 p.m. – 8:00 p.m. ET to show your viewers what they need to safely see the eclipse whether they’re inside the path of totality or not. You should never look directly at the sun! The only safe way to look directly at the sun or partially eclipsed sun is through special-purpose solar filters, such as “eclipse glasses” or hand-held solar viewers. An eclipse is a striking phenomenon you won't want to miss, but you must carefully follow safety procedures.Solar eclipses happen somewhere in the world about every 18 months, but much of the time it happens over the ocean. To have an eclipse travel across so much land where millions of people live is incredibly rare, and makes for a unique opportunity for so many to witness one of nature’s most impressive shows. It’s also a great opportunity for scientists to see the sun’s faint outer atmosphere and evaluate how Earth responds to the sudden darkening.Take this opportunity to step outside and safely watch one of nature’s best shows!*** To book a window ***Contact Michelle Handleman michelle.z.handleman@nasa.gov / 301-286-0918HD Satellite Digital Coordinates for G17-K20/Up: Galaxy 17, Ku-band Xp 20, Slot Upper | 91.0 ° W Longitude | DL 12109.0 MHz | Vertical Polarity | QPSK/DVB-S | FEC 3/4 | SR 13.235 Mbps | DR 18.2954 MHz | HD 720p | Format MPEG2 | Chroma Level 4:2:0 | Audio EmbeddedSuggested Questions:1. The anticipated solar eclipse is just days away! What will we experience next week?2. We’ve been told never to look directly at the sun (even with sunglasses!). How can we enjoy this eclipse safely?3. For those in the path of totality – when is it safe to finally take off our solar glasses?4. We’re not in the path of totality – what interesting things should we lookout for?5. Why are you excited for this eclipse?6. Where can we learn more?Extra Questions for Longer Interviews:7. How did a picture of an eclipse in 1919 prove Einstein’s theory of relativity?8. Eclipses are actually a special type of transit. How are transits helping scientists search for life on other planets?9. Why does an eclipse only last for a few minutes?10. What happens to Earth during the eclipse?11. If you were looking back at Earth during the eclipse what would you see?12. How has our precise mapping of the moon helped us predict the path of eclipses?13. How long and where was the longest ever recorded eclipse?Location: NASA’s Goddard Space Flight Center/Greenbelt, MarylandInterviews With:Dr. Michelle Thaller / NASA ScientistDr. Alex Young / NASA ScientistDr. Jim Garvin / NASA ScientistDr. Nicholeen Viall / NASA ScientistDr. Eric Christian / NASA ScientistDr. Yari Collado-Vega / NASA Scientist [Spanish speaker]Dr. Geronimo Villanueva / NASA Scientist [Spanish speaker]https://eclipse2017.nasa.gov/@NASASunHow to photograph an eclipse.Planning to take photos of the eclipse? Check out our tips for capturing the best images:#Eclipse2017 ||
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ID: 12664 Produced Video
One Month & Counting: Solar Eclipse Liveshots (July 21, 2017)
Read moreCanned interviews will be available by 6:00 p.m. ET on July 20, 2017. || One Month and Counting: Solar Eclipse Visible From Everywhere in North AmericaBecome a Citizen Scientist During the Eclipse, Using the GLOBE Phone AppHelp Scientists Study What Happens When Earth Goes Dark During the Solar EclipseOne of the most anticipated solar eclipses in history is just a month away. The August 21 solar eclipse provides a unique opportunity to study our planet and what happens when Earth goes dark during an eclipse. It’s also an opportunity for what may be the largest citizen science project of all time.On that Monday, the moon’s shadow will darken the sky, causing temperatures to drop and stars to become visible in the normally day lit sky. This brief hiccup in the usual day-night cycle changes the amount of energy an area gets from the sun.NASA scientists hope to learn just how much Earth’s environment changes during this historic eclipse and they need help from your viewers! Using the GLOBE Observer phone application, curious eclipse onlookers can become citizen scientists. This resulting data will help us better understand the important relationship between the sun and Earth.Join NASA scientists on Friday, July 21 from 6:00 a.m. – 12:00 p.m. ET to find out where your viewers can see the eclipse and how they can participate, whether they’re viewing from the path of totality or not!Everyone in North America (weather dependent) will experience an eclipse, one of nature’s rarest shows – even those outside the path of totality. For the first time since 1918, the dark shadow of the moon will sweep coast-to-coast across the United States, putting 14 states in the path of totality and providing a spectacular view of a partial eclipse across all 50 states.HD Satellite Coordinates for G17-K18/LO: Galaxy 17 Ku-band Xp 18 Slot Lower| 91.0 ° W Longitude | DL 12051.0 MHz | Vertical Polarity | QPSK/DVB-S | FEC 3/4 | SR 13.235 Mbps | DR 18.2954 MHz | HD 720p | Format MPEG2 | Chroma Level 4:2:0 | Audio Embedded*** To book a window contact*** Clare Skelly / clare.a.skelly@nasa.gov / (301) 286-4994Suggested Questions:1. What’s going to happen one month from today? [answer includes safety information]2. Why is this eclipse special to NASA?3. How can our viewers participate?4. We live on a solar powered planet. How does energy from the sun impact Earth?5. Where can we learn more?Extra Questions for Longer Interviews:6. Tell us about the new mission NASA is preparing to launch that will continue to collect information on the sun-Earth relationship.7. Can solar eclipses be seen from other planets and what do they look like?8. An eclipse is a type of transit. How can astronomers use transits to detect planets orbiting other stars?Location: NASA’s Goddard Space Flight Center / Greenbelt, MarylandScientists:Dr. Michelle Thaller / NASA ScientistDr. Jim Garvin / NASA ScientistDr. Alex Young / NASA ScientistDr. Ivona Cetinic / NASA ScientistVideo: NASA will roll all insert videos during live interviews. If needed, stations can roll a clean feed of all video at 5:45 a.m. ET on July 21, 2017, at the above listed satellite.Download the GLOBE Observer Application for iOS or Android.For eclipse information, maps and safety: https://eclipse2017.nasa.gov/To learn more about the GLOBE program: https://observer.globe.gov/For more information about how NASA studies Earth: https://www.nasa.gov/earth ||
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ID: 4579 Visualization
Flying Around The Eclipse Shadow
Read moreA view of the Moon's shadow during the August 21, 2017 eclipse from both the night and day sides of the Earth. || This visualization combines the views from several previous visualizations (#4390, #4321, and #4314) to create a continuous camera flight from the night side of the Earth to the day side, showing the relationship of the Earth, Moon, and Sun during the August 21, 2017 eclipse. It shows the direction of the Moon's motion and the Earth's rotation, the complete path of the umbra from the moment it touches down on the Earth until the moment it departs, and the true scale of the Earth-Moon system. ||
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ID: 12625 Produced Video
Rare Total Solar Eclipse Is Only Two Months Away Live Shots 6.21.17
Read moreB-roll for the live shots || The Countdown is on for Rare Solar Eclipse Visible Across all of North AmericaFor the First Time in Nearly 100 Years, Millions of Americans Coast-to-Coast Will see an Eclipse Chat with NASA to find out how you can catch this spectacular eventOn August 21, 2017, daylight will fade to the level of a moonlit night as millions of Americans experience one of nature’s most awe-inspiring shows – a total solar eclipse. For the first time since 1918, the dark shadow of the moon will sweep coast-to-coast across the United States, putting 14 states in the path of totality and providing a spectacular view of a partial eclipse across all 50 states.NASA scientists are available Wednesday, June 21, from 6:00 a.m. – 12:00 p.m. ET to show your viewers the path of the eclipse, what they need to see it safely and talk about the unprecedented science that will be gathered from one of the most anticipated and widely observed celestial events in history. We’ll also give your viewers a sneak peek of a press conference about the eclipse NASA is having later that day.A solar eclipse happens when a rare alignment of the sun and moon casts a shadow on Earth. NASA knows the shape of the moon better than any other planetary body, and this data allows us to accurately predict the shape of the shadow as it falls on the face of Earth. While everyone in the U.S. will see the eclipse if their local skies are clear, people standing in the path of totality – completely in the moon’s shadow – will see stars and planets become visible in what is normally a sunlit sky. Eclipses provide an unprecedented opportunity for us to see the sun’s faint outer atmosphere in a way that cannot be replicated by current human-made instruments. Scientists believe this region of the sun is the main driver for the sun’s constant outpouring of radiation, known as the solar wind, as well as powerful bursts of solar material that can be harmful to our satellites, orbiting astronauts and power grids on the ground. HD Satellite Coordinates for G17-K18/LO: Galaxy 17 Ku-band Xp 18 Slot Lower | 91.0 ° W Longitude | DL 12051.0 MHz | Vertical Polarity | QPSK/DVB-S | FEC 3/4 | SR 13.235 Mbps | DR 18.2954 MHz | HD 720p | Format MPEG2 | Chroma Level 4:2:0 | Audio Embedded**To book a window contact** / Michelle Handleman / michelle.z.handleman@nasa.gov / 301-286-0918Suggested Questions:1. This is the first time in nearly 100 years that the United States will have the opportunity to see a total solar eclipse coast-to-coast! What will happen on August 21?2. This eclipse will be the most widely observed and shared celestial event in U.S. history. Why are scientists excited for this eclipse?3. Eclipses allow scientists to see the sun’s faint outer atmosphere, which is actually hotter than its surface. What can you tell us about NASA’s upcoming mission that will touch the sun?4. How does NASA’s study of our sun help us explore the solar system?5. How does NASA’s mapping of the moon give us the accurate path of totality?6. Where can we learn more?Live Shot Details:Location: NASA’s Goddard Space Flight Center/Greenbelt, MarylandScientists:Dr. Alex Young / NASA ScientistDr. Nicholeen Viall / NASA ScientistDr. Noah Petro / NASA ScientistDr. Geronimo Villanueva [in Spanish] / NASA ScientistTo learn more visit:Eclipse Across AmericaOn Twitter @NASASun ||
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ID: 12412 Produced Video
Tracing the 2017 Solar Eclipse
Read moreWhen depicting an eclipse path, data visualizers have usually chosen to represent the moon's shadow as an oval. By bringing in a variety of NASA data sets, visualizer Ernie Wright has created a new and more accurate representation of the eclipse. For the first time, we are able to see that the moon's shadow is better represented as a polygon. This more complicated shape is based NASA's Lunar Reconnaissance Orbiter's view of the mountains and valleys that form the moon's jagged edge. By combining moon's terrain, heights of land forms on Earth, and the angle of the sun, Wright is able to show the eclipse path with the greatest accuracy to date. ||
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ID: 4466 Visualization
Insolation during the 2017 Eclipse
Read moreInsolation (the amount of sunlight reaching the ground) is affected dramatically by the Moon's shadow during the August 21, 2017 total solar eclipse. || On an ordinary day, the insolation — the amount of sunlight hitting a given spot on the Earth — is proportional to the sine of the Sun's altitude. When the Sun is 30° above the horizon, the sunlight energy per square meter is half of what it is when the Sun is directly overhead. This relationship is the reason that the tropics are hot and the poles are cold. Combined with day length, it's also the reason for the difference in temperature between the seasons at temperate latitudes.As this animation shows, the Moon's shadow dramatically, if temporarily, affects insolation in the continental United States during the total solar eclipse of August 21, 2017. The effect is readily apparent to observers in the path of totality. As the umbra passes overhead, the temperature drops by several degrees. The cooled column of air within the shadow cone can even influence cloud formation and the speed and direction of the wind.The insolation map in the animation combines solar altitude with obscuration, the fraction of the Sun's area blocked by the Moon during the eclipse. It ignores a number of other factors, including atmospheric scattering, refraction, and cloud cover, that also play a role in the amount of sunlight that reaches the ground. ||
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ID: 4467 Visualization
2017 Solar Eclipse from L1
Read moreThe August 21, 2017 total solar eclipse as seen from a satellite in orbit around L1, a point about 1.5 million kilometers from Earth in the direction of the Sun. || A number of satellites will be watching the August 21, 2017 total solar eclipse from space. One of them, the Deep Space Climate Observatory (DSCOVR) will see the eclipse from its orbit around L1, the Lagrange point located about 1.5 million kilometers from Earth along the Earth-Sun line. From this vantage point, DSCOVR's EPIC camera continuously images the full sunlit disk of the Earth.This animation simulates the view that EPIC will have of the 2017 eclipse. The shadow size and opacity are based on the eclipse obscuration, the fraction of the Sun's disk covered by the Moon. The bright spot near the equator is the reflection of the Sun on the water. The red streak shows the path of totality, the locations on the Earth where observers will see the Sun completely covered by the Moon.EPIC will see both the Moon's shadow and the Sun's reflection because DSCOVR's orbit takes it several degrees off both the Sun-Earth line and the Sun-Moon line. For the same reason, the Moon will not be in the frame. The animation places the virtual camera in a plausible position for DSCOVR. The actual position of the spacecraft at the time of the eclipse will be affected by adjustments to its orbit that may be made in the coming months.EPIC has already captured the total solar eclipse of March, 2016. ||
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ID: 12049 Produced Video
NASA On Air: NASA Previews 2017 Total Solar Eclipse (11/11/2015)
Read moreLEAD: NASA scientists and astronomers are already planning for the first total solar eclipse for the United States in 38 years. 1. On August 21, 2017, the moon will pass between the sun and Earth in an alignment that will cast the moon's shadow onto Earth. 2. A dark shadow of the moon, 170 miles wide, will sweep across the U.S. over the course of one-and-a-half hours. 3. People in cities lying within the narrow path of the shadow (red line in the video) will experience an eerie sense of twilight as day turns to night and back to day again within roughly 2-2.5 minutes. TAG: Solar astronomers will use the solar eclipse to study the outer atmosphere of the sun. ||
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ID: 4314 Visualization
2017 Total Solar Eclipse in the U.S.
Read moreA view of the United States during the total solar eclipse of August 21, 2017, showing the umbra (black oval), penumbra (concentric shaded ovals), and path of totality (red) through or very near several major cities. || On Monday, August 21, 2017, the Moon will pass in front of the Sun, casting its shadow across all of North America. This will be the first total solar eclipse visible in the contiguous United States in 38 years.The Moon's shadow can be divided into areas called the umbra and the penumbra. Within the penumbra, the Sun is only partially blocked, and observers experience a partial eclipse. The much smaller umbra lies at the very center of the shadow cone, and anyone there sees the Moon entirely cover the Sun in a total solar eclipse.In the animation, the umbra is the small black oval. The red streak behind this oval is the path of totality. Anyone within this path will see a total eclipse when the umbra passes over them. The much larger shaded bullseye pattern represents the penumbra. Steps in the shading denote different percentages of Sun coverage (eclipse magnitude), at levels of 90%, 75%, 50% and 25%. The yellow and orange contours map the path of the penumbra. The outermost yellow contour is the edge of the penumbra path. Outside this limit, no part of the Sun is covered by the Moon.The numbers in the lower left corner give the latitude and longitude of the center of the umbra as it moves eastward, along with the altitude of the Sun above the horizon at that point. Also shown is the duration of totality: for anyone standing at the center point, this is how long the total solar eclipse will last. Note that the duration varies from just 2 minutes on the West Coast to 2 minutes 40 seconds east of the Mississippi River.About AccuracyYou might think that calculating the circumstances of an eclipse would be, if not easy, then at least precise. If you do the math correctly, you’d expect to get exactly the same answers as everyone else. But the universe is more subtle than that. The Earth is neither smooth nor perfectly spherical, nor does it rotate at a perfectly constant, predictable speed. The Moon isn’t smooth, either, which means that the shadow it casts isn’t a simple circle. And our knowledge of the size of the Sun is uncertain by a factor of about 0.2%, enough to affect the duration of totality by several seconds.Everyone who performs these calculations will make certain choices to simplify the math or to precisely define an imperfectly known number. The choices often depend on the goals and the computing resources of the calculator, and as you'd expect, the results will differ slightly. You can get quite good results with a relatively simple approach, but it sometimes takes an enormous effort to get only slightly better answers.The following table lists some of the constants and data used for this animation.Earth radius6378.137 kmEarth flattening1 / 298.257 (the WGS 84 ellipsoid)Moon radius1737.4 km (k = 0.2723993)Sun radius696,000 km (959.634 arcsec at 1 AU)EphemerisDE 421Earth orientationearth_070425_370426_predict.bpc (ΔT corrected)Delta UTC68.184 seconds (TT – TAI + 36 leap seconds)A number of sources explain Bessel’s method of solar eclipse calculation, including chapter 9 of Astronomy on the Personal Computer by Oliver Montenbruck and Thomas Pflager and the eclipses chapter of The Explanatory Supplement to the Astronomical Almanac. The method was adapted to the routines available in NAIF's SPICE software library.The value for the radius of the Moon is slightly larger than the one used by Fred Espenak and slightly smaller than the one used by the Astronomical Almanac. The Sun radius is the one used most often, but see figure 1 in M. Emilio et al., Measuring the Solar Radius from Space during the 2003 and 2006 Mercury Transits for a sense of the uncertainty in this number.Both the elevations of locations on the Earth and the irregular limb of the Moon were ignored. The resulting small errors mostly affect the totality duration calculation, but they tend to cancel out—elevations above sea level slightly lengthen totality, while valleys along the lunar limb slightly shorten it. The effect on the rendered images is negligible (smaller than a pixel).Another minor complication that's ignored here is the difference between the Moon's center of mass (the position reported in the ephemeris) and its center of figure (the center of the disk as seen from Earth). These two centers don't exactly coincide because the Moon's mass isn't distributed evenly, but the difference is quite small, about 0.5 kilometers. ||
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ID: 4321 Visualization
2017 Eclipse Shadow Cones
Read moreThe umbral and penumbral shadow cones travel across the surface of the Earth during the August 21, 2017 total solar eclipse. || A solar eclipse occurs when the Moon's shadow falls on the Earth. The shadow comprises two concentric cones called the umbra and the penumbra. Within the smaller, central umbra, the Sun is completely blocked by the Moon, and anyone inside the umbra sees a total eclipse. Within the larger penumbra, the Sun is only partially blocked.In this animation, the umbra and penumbra cones are viewed through a telescopic lens on a virtual camera located far behind the Moon. Long focal lengths like the one used here appear to compress the distance between near and far objects. Despite appearances, the geometry of the scene is correct. The Earth is roughly 112 lunar diameters beyond the Moon, and the angle at the apex of the umbral cone is only about half a degree.From this point of view directly behind the Moon, the edges of the shadow cones look circular. The edge of the penumbra is outlined in yellow. It passes over all of North and Central America and the Amazon basin, as well as Greenland and the North Pole. Everyone there will see at least a partial eclipse. The path of the umbra (the small black dot) crosses the United States from Oregon to South Carolina. ||
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ID: 4324 Visualization
2017 Eclipse and the Moon's Orbit
Read moreThe Moon orbits the Earth in the months prior to the August 21, 2017 total solar eclipse. Viewed from above, the Moon's shadow appears to cross the Earth every month, but a side view reveals the five-degree tilt of the Moon's orbit. Its shadow only hits the Earth when the line of nodes, the fulcrum of its orbital tilt, is pointed toward the Sun. || Solar eclipses can only occur at New Moon, when the Moon is between the Earth and the Sun. But not every New Moon produces an eclipse. The Moon's orbit is slightly tilted, and as seen in this animation, the tilt causes the Moon's shadow to miss the Earth during most New Moons—about five out of six, in fact.As the Earth-Moon system orbits the Sun throughout the year, the Moon's orbital tilt changes direction relative to the Sun. Sometimes the up side of the orbit is facing the Sun, and sometimes the down side. Twice a year, for about a month, what's facing the Sun is the line dividing the up and down sides. This is the line of nodes, the intersection of the Earth-Moon plane and the ecliptic or Earth-Sun plane. A solar eclipse can only occur at a New Moon that falls within one of these month-long eclipse seasons. That's when the Moon is close enough to the ecliptic to actually come between the Earth and the Sun.In this animation, the olive-colored square represents the ecliptic plane, while the light blue circle shows the plane of the Moon's orbit. The darker half of the lunar orbit plane is below (south of) the ecliptic, and the dividing line between light and dark is the line of nodes.The radial grid on the lunar orbit plane is stationary relative to the stars. It appears to rotate because our point of view is fixed to the Earth-Sun line; we're following the Earth as it orbits the Sun. At first glance, the line of nodes appears to be tracking with the grid, but in reality it's slowly turning westward (clockwise), completing a full revolution in 18.6 years.Unlike most illustrations of this kind, the Earth and the Moon are to scale. The Sun is off-screen to the left, about 400 times farther than the Earth-Moon distance and roughly twice as big as the Moon's orbit. ||
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ID: 12481 Produced Video
2017's All American Solar Eclipse
Read moreOn August 21, 2017, a solar eclipse will be visible across North America. || On Monday, Aug. 21, 2017, a total eclipse will cross the entire United States, coast-to-coast, for the first time since 1918. Weather permitting, the entire continent will have the opportunity to view a partial eclipse as the moon passes in front of the sun, casting a shadow on Earth’s surface. Some will see a total eclipse along a path that begins near Lincoln City, Oregon and ends near Charleston, South Carolina. Solar eclipses occur when the moon blocks any part of the sun. Total solar eclipses, however, are only possible on Earth because of a cosmic quirk of geometry: The sun’s diameter is about 400 times wider than the moon’s, but it is also about 400 times farther away. The result is that the sun and the moon appear to be the same size from our perspective. When they line up just right, the moon can obscure the sun’s entire surface, an occurrence once every 12 to 18 months. Partial solar eclipses, on the other hand, occur when the alignment is such that the moon blocks only part of the sun, and these can occur more frequently. During a total eclipse, we have the rare opportunity to look directly at the sun’s vast, striking outer atmosphere, the corona. The corona appears as pearly white rays and streamers, radiating around the lunar disk. Watch the video to learn more. ||
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ID: 12117 Produced Video
Visualizing the 2017 All-American Eclipse
Read moreComplete transcript available.Watch this video on the NASAgovVideo YouTube channel.This video is also available on our YouTube channel. || On August 21, 2017, the Earth will cross the shadow of the Moon, creating a total solar eclipse. Eclipses happen about every six months, but this one is special. For the first time in almost 40 years, the path of the Moon's shadow passes through the continental United States.The video features several visualizations of this event. From behind the Earth, we see the night sides of both the Earth and Moon and the umbral and penumbral shadow cones projecting from the Moon. We then see the tilted orbit of the Moon and the long, thin shadow cones striking the Earth. In the view from behind the Moon, we see the daylit far side of the Moon and the western hemisphere of the Earth, and from this vantage point, the outline of the shadow on the Earth is circular.Most of the video shows a close-up view of the U.S. during the eclipse. Everyone there will see the Moon at least partially block the Sun, but those along the path of totality, shown in red, will see the Moon block the Sun entirely. The appearance of the Sun throughout the eclipse is shown for a number of locations in North America, with each Sun image oriented to the local horizon.Some of the visualizations use extremely long telephoto lenses to visually compress the scene, but all of them are geometrically accurate and true to scale. Go here for more details about the calculations and for links to each of the visualizations. ||
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