Flying Around The Eclipse Shadow

This video explains how our moon creates a solar eclipse, why it's such a rare event to see, and how data from NASA's Lunar Reconnaissance Orbiter has enhanced our ability to map an eclipse's path of totality.Music Provided by Universal Production Music: “Bring Me Up” – Anders Gunnar Kampe & Henrik Lars Wikstrom.Watch this video on the NASA.gov Video YouTube channel. While the sun is the main focus of a solar eclipse, our moon plays the most crucial role in creating this unique event. This video tutorial explains what happens during a total solar eclipse and a partial eclipse and how often they both occur. The video also explains how a solar eclipse differs from a lunar eclipse, and gives a helpful tip on how to remember the difference. In addition, the video examines how the two parts of the moon’s shadow, the umbra and penumbra, affect how we see an eclipse on the Earth, and illustrates the surprising true shape of the umbra. The video concludes by highlighting how data from NASA’s Lunar Reconnaissance Orbiter has helped us better map a solar eclipse’s path of totality. Visualizations included in this piece showcase the August 21, 2017 total solar eclipse happening in the United States. Related pages

Canned interviews will be available by 6:00 p.m. ET on July 20, 2017. B-roll package for liveshot. Canned soundbites with Dr. Alex Young. TRT 4:59. Includes full transcript answering the following 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. How can we safely view the eclipse?6. Where can we learn more? Soundbites with NASA Scientist Dr. Michelle Thaller looking off camera. TRT 4:06. Includes full text of the soundbites. SOTs are separated by a slate. She answers the following questions:1. What's going to happen one month from today?2. What's it like to see an eclipse?3. How can we view the eclipse safely?4. How can our viewers participate?5. What is NASA's new mission that will collect information on the sun-Earth relationship? 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 For More InformationSee [https://eclipse2017.nasa.gov/](https://eclipse2017.nasa.gov/) Related pages

B-roll for the live shots Canned interview with NASA Scientist Dr. Nicholeen Viall looking off camera. Soundbites are separated by slates. Includes transcript of soundbites. Canned interview in Spanish with Dr. Yari Collado-Vega. Soundbites are separated with slates Soundbites with Drs. Alex Young and Noah Petro. TRT 5:41. Includes full transcript with timecodes 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 For More InformationSee [https://eclipse2017.nasa.gov/](https://eclipse2017.nasa.gov/) Related pages

The Moon moves right to left in its orbit around the Earth. The shadow it casts hits the Earth during the August 21, 2017 total solar eclipse. A print-resolution still image showing the Earth, Moon, and Sun at 17:05:40 UTC during the August 21, 2017 eclipse. The image is 12 × 9 inches at 300 DPI. 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. Related pages

A 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. A 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). This version omits the city and state names and the statistics display. A 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). This version includes images of the Sun showing its appearance in a number of locations, each oriented to the local horizon. 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. Related pages

The 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. Related pages