Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2010 August 4
See Explanation. Go online for the highest resolution available.

Eclipse Shadow Cone Over Patagonia
Credit & Copyright: Daniel Fischer (Cosmic Mirror)

Explanation: Sometimes, during a total eclipse of the Sun, a strange shadow of darkness can be seen stretching off into the distance. Called shadow cones, they are visible because the Earth's atmosphere is not completely transparent, scattering sunlight and hence appearing blue during the day. Shadow cones are particularly dramatic for eclipses near the horizon, as geometry creates a long corridor of sun-blocked air. Visible above is a shadow cone caught during a sunset total solar eclipse visible last month from Patagonia, Argentina. The eclipsed Sun itself still appears bright around the edges of the Moon because of light from the surrounding corona. A few minutes later, the Moon began to move away from the Sun as both set behind distant Andes mountains.

View this page (with external links) online at
http://apod.gsfc.nasa.gov/apod/ap100804.html.


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Official: Phillip Newman. Specific rights apply.
A service of: ASD at NASA/GSFC
& Michigan Tech. U.

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