[gatagato]

Anticrepuscular rays are similar to crepuscular rays, but seen opposite the sun in the sky. Anticrepuscular rays are near-parallel, but appear to converge at the antisolar point because of linear perspective. Anticrepuscular rays are most frequently visible near sunrise or sunset. Crepuscular rays are usually much brighter than anticrepuscular rays. This is because for crepuscular rays, seen on the same side of the sky as the sun, the atmospheric light scattering and making them visible is taking place at small angles (see Mie theory).

Although anticrepuscular rays appear to converge onto a point opposite the sun, the convergence is actually an illusion. The rays are in fact (almost) parallel, and the apparent convergence is to the vanishing point at infinity.

The spectacular video below was taken in Brazil, the cameraman is very puzzled and says that the sun is opposite to where the column of light seems to come from: basically, he was seeing an apparent sunshine in front of him while the sun was right behind him.
Anticrepuscular Rays aren't rare, if you want to try to catch them on camera, you have to turn around when ordinary crepuscular rays are visible, and if you have some luck...


Chandler Arizona, September 8th @ 6:25pm. Anticrepuscular Rays extend from the western setting sun to the eastern horizon. Photo by Ian Schlueter


Astronomy Picture of the Day - 2006 September 17
Credit & Copyright: Daniel Herron

Explanation: What's happening over the horizon? Although the scene may appear somehow supernatural, nothing more unusual is occurring than a setting Sun and some well placed clouds. Strangely, the actual sunset was occurring in the opposite direction from where the camera was pointing. Pictured above are anticrepuscular rays. To understand them, start by picturing common crepuscular rays that are seen any time that sunlight pours though scattered clouds. Now although sunlight indeed travels along straight lines, the projections of these lines onto the spherical sky are great circles. Therefore, the crepuscular rays from a setting (or rising) sun will appear to re-converge on the other side of the sky. At the anti-solar point 180 degrees around from the Sun, they are referred to as anticrepuscular rays. While enjoying the sunset after visiting NASA's Kennedy Space Center in Florida, the photographer chanced to find that an even more spectacular sight was occurring in the other direction just over the Atlantic Ocean -- a particularly vivid set of anticrepuscular rays.



http://en.wikipedia.org/wiki/Anticrepuscular_rays
http://www.atoptics.co.uk/atoptics/anti1.htm
http://apod.nasa.gov/apod/ap060917.html

[kellyhound]

very cool sight

[Faline]

Stunning, shit i'd love to witness