Darkened by the Moon’s Shadow

Darkened by the Moon’s Shadow

On October 14, 2023, the Moon aligned with the Sun and Earth to produce an annular solar eclipse. The spectacle bathed millions of Americans in a lunar shadow as the Moon blocked the Sun’s rays.

An annular eclipse occurs when the Moon passes in front of the Sun but is too far from Earth to completely obscure it. The Moon is at or near its farthest distance from Earth—known as its apogee—during an annular eclipse, making it look smaller in the sky. This leaves the Sun’s edges exposed in a red-orange ring, dubbed the “ring of fire.” A satellite caught an earthly view of the event, as the Moon’s shadow crossed North America.

The above image was acquired during the eclipse by NASA’s EPIC (Earth Polychromatic Imaging Camera) imager aboard DSCVR (Deep Space Climate Observatory), a joint NASA, NOAA, and U.S. Air Force satellite. The sensor provides frequent global views of Earth from its position at Lagrange Point 1, a gravitationally stable point between the Sun and Earth about 1.5 million kilometers from Earth. In this view, acquired at 16:58 Universal Time (11:58 a.m. Central Daylight Time), the shadow, or umbra, from the Moon can be seen falling across the southeastern coast of Texas, near Corpus Christi.

While the annular eclipse was partially visible across the entire United States, Mexico, and countries in Central and South America, the path of annularity—where the largest area of the Sun was covered by the Moon from the observers' point of view—was the best place to view it.

The map above, developed by NASA’s Scientific Visualization Studio, shows the dark path of the annularity stretching across the lower 48 states from Oregon to Texas. The map uses datasets from several NASA missions. Imagery from MODIS (Moderate Resolution Imaging Spectroradiometer) instruments on the Terra and Aqua satellites was the source of the Blue Marble Next Generation composite used to depict the terrain.

The path of annularity started in Oregon around 9:13 a.m. Pacific Daylight Time, though cloudy skies blocked the view for some sky watchers. The shadow then moved southeast across Nevada, Utah, Arizona, Colorado, and New Mexico, before passing over Texas and the Gulf of Mexico.

Also visible on the map within the path are duration contours. These delineate the length of time annularity lasted. The closer to the center of the solar eclipse path, the longer it lasted. For the annular path, times range from a few seconds on the outer edge to a maximum of around 4.5 minutes in the center.

The next annular solar eclipse visible from the United States will be on June 21, 2039. But a total solar eclipse will darken skies from Texas to Maine on Monday, April 8, 2024.

NASA image courtesy of the DSCOVR EPIC team. NASA Scientific Visualization Studio map by Michala Garrison. Story by Emily Cassidy.

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