{"id":11995,"date":"2024-09-19T12:09:42","date_gmt":"2024-09-19T16:09:42","guid":{"rendered":"https:\/\/zobi.alcowep.com\/bourtagshdrevxnls658739\/nasa-develops-process-to-create-very-accurate-eclipse-maps\/"},"modified":"2024-09-19T12:09:42","modified_gmt":"2024-09-19T16:09:42","slug":"nasa-develops-process-to-create-very-accurate-eclipse-maps","status":"publish","type":"post","link":"https:\/\/zobi.alcowep.com\/bourtagshdrevxnls658739\/nasa-develops-process-to-create-very-accurate-eclipse-maps\/","title":{"rendered":"NASA Develops Process to Create Very Accurate Eclipse Maps"},"content":{"rendered":"

NASA Develops Process to Create Very Accurate Eclipse Maps<\/h2>\n

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3 min read<\/p>\n

NASA Develops Process to Create Very Accurate Eclipse Maps<\/h1>\n<\/div>\n<\/div>\n<\/div>\n

New NASA research reveals a process to generate extremely accurate eclipse maps, which plot the predicted path of the Moon\u2019s shadow as it crosses the face of Earth. Traditionally, eclipse calculations assume that all observers are at sea level on Earth and that the Moon is a smooth sphere that is perfectly symmetrical around its center of mass. As such, these calculations do not take into account different elevations on Earth or the Moon\u2019s cratered, uneven surface.<\/p>\n

For slightly more accurate maps, people can employ elevation tables and plots of the lunar limb \u2014 the edge of the visible surface of the Moon as seen from Earth. However, now eclipse calculations have gained even greater accuracy by incorporating lunar topography data from NASA\u2019s LRO (Lunar Reconnaissance Orbiter<\/a>) observations.<\/p>\n

Using LRO elevation maps, NASA visualizer Ernie Wright at NASA\u2019s Goddard Space Flight Center in Greenbelt, Maryland, created a continuously varying lunar limb profile as the Moon\u2019s shadow passes over the Earth. The mountains and valleys along the edge of the Moon\u2019s disk affect the timing and duration of totality by several seconds. Wright also used several NASA data sets to provide an elevation map of Earth so that eclipse observer locations were depicted at their true altitude.<\/p>\n

The resulting visualizations show something never seen before: the true, time-varying shape of the Moon\u2019s shadow, with the effects of both an accurate lunar limb and the Earth\u2019s terrain.<\/p>\n

\u201cBeginning with the 2017 total solar eclipse, we\u2019ve been publishing maps and movies of eclipses<\/a> that show the true shape of the Moon\u2019s central shadow \u00a0\u2014 the umbra,\u201d said Wright.<\/p>\n

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\"A<\/a><\/figure>
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A map showing the umbra (the Moon\u2019s central shadow) as it passes over Cleveland at 3:15 p.m. local time during the April 8, 2024, total solar eclipse.<\/div>\n
NASA SVS\/Ernie Wright and Michaela Garrison<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

\u201cAnd people ask, why does it look like a potato instead of a smooth oval? The short answer is that the Moon isn\u2019t a perfectly smooth sphere.\u201d<\/p>\n

The mountains and valleys around the edge of the Moon change the shape of the shadow. The valleys are also responsible for Baily\u2019s beads and the diamond ring, the last bits of the Sun visible just before and the first just after totality.<\/p>\n

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\"A<\/a><\/figure>
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A computer simulation of Baily\u2019s beads during a total solar eclipse. Data from Lunar Reconnaissance Orbiter makes it possible to map the lunar valleys that create the bead effect. <\/div>\n
NASA SVS\/Ernie Wright<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

Wright is lead author of a paper<\/a> published September 19 in The Astronomical Journal that reveals for the first time exactly how<\/em> the Moon\u2019s terrain creates the umbra shape. The valleys on the edge of the Moon act like pinholes<\/a> projecting images of the Sun onto the Earth\u2019s surface.<\/p>\n

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\"A<\/a><\/figure>
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A visualization of Sun images being projected from lunar valleys that are acting like pinhole projectors. Light rays from the Sun converge on each valley, then spread out again on their way to the Earth.<\/div>\n
NASA SVS\/Ernie Wright<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

The umbra is the small hole in the middle of these projected Sun images, the place where none of the Sun images reach.<\/p>\n

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\"Conceptual<\/a><\/figure>
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Viewed from behind the Moon, the Sun images projected by lunar valleys on the Moon\u2019s edge fall on the Earth\u2019s surface in a flower-like pattern with a hole in the middle, forming the umbra shape.<\/div>\n
NASA SVS\/Ernie Wright<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

The edges of the umbra are made up of small arcs from the edges of the projected Sun images.<\/p>\n

This is just one of several surprising results that have emerged from the new eclipse mapping method described in the paper. Unlike the traditional method invented 200 years ago, the new way renders<\/em> eclipse maps one pixel at a time, the same way 3D animation software creates images. It\u2019s also similar to the way other complex phenomena, like weather, are modeled in the computer by breaking the problem into millions of tiny pieces, something computers are really good at, and something that was inconceivable 200 years ago.<\/p>\n

For more about eclipses, refer to:<\/p>\n

https:\/\/science.nasa.gov\/eclipses<\/a><\/p>\n

By Ernie Wright and Susannah Darling<\/strong><\/p>\n

NASA\u2019s Goddard Space Flight Center, Greenbelt, Md.<\/strong><\/p>\n

Media Contact:<\/strong><\/p>\n

Nancy Neal-Jones
NASA\u2019s Goddard Space Flight Center, Greenbelt, Md.
301-286-0039
nancy.n.jones@nasa.gov<\/a> <\/em><\/p>\n

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