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Астронет: Астрономическая картинка дня Противосумеречные лучи над Флоридой http://variable-stars.ru/db/msg/1634025/eng |
Credit & Copyright: Bryan Goff
Explanation:
What's happening behind those clouds?
Although the scene may appear somehow
supernatural,
nothing more unusual is occurring than a
Sun setting on the other side of the sky.
Pictured here 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.
Featured here is a particularly striking display of
anticrepuscular rays photographed in 2016 over
Dry Tortugas National Park
in Florida,
USA.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.