Earth  Sun  Planets and Moons  ID: 4321

2017 Eclipse Shadow Cones

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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Visualization Credits

Ernie Wright (USRA): Lead Visualizer
Genna Duberstein (USRA): Producer
Please give credit for this item to:
NASA's Scientific Visualization Studio

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Data Used:
LRO/LROC/WAC 643nm High Sun Global Mosaic
JPL DE421 also referred to as: DE421
Ephemeris - NASA/JPL
LRO/LOLA/Digital Elevation Map also referred to as: DEM
Terra and Aqua/MODIS/Blue Marble: Next Generation also referred to as: BMNG
The Blue Marble data is courtesy of Reto Stockli (NASA/GSFC).
Note: 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.

This item is part of this series:
2017 Solar Eclipse

SVS >> Moon
SVS >> Solar Eclipse
SVS >> Hyperwall
SVS >> Eclipse
SVS >> Heliophysics
SVS >> Sun-Earth-Moon Interactions
SVS >> Sun and Earth
NASA Science >> Earth
NASA Science >> Sun
NASA Science >> Planets and Moons