This animation begins with an image of the Moon’s shadow on the Earth captured by the Lunar Reconnaissance Orbiter. As the levels of gray in the image are gradually adjusted the background saturates until the features of the landscape disappear, making it possible to see the edge of the total solar eclipse. As the gray levels are restored, the umbra (the completely shadowed area) becomes visible—followed by the penumbra (partial shadow) where part of the Sun is not completely covered by the Moon. The Moon is a high-contrast target with very bright materials next to dark materials, so LRO’s Narrow Angle Camera can record 3600 gray levels. Most digital cameras record only 255 levels of gray. In this animation the 3,600 levels of gray were compressed to 255 levels so the image can be rendered on a typical computer screen.
Image Credits: NASA / GSFC / Arizona State University