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Астронет: Астрономическая картинка дня Огненная радуга над Нью-Джерси http://variable-stars.ru/db/msg/1228215/eng |
Credit & Copyright: Paul Gitto
(Arcturus Observatory)
Explanation:
What is that inverted rainbow in the sky?
Sometimes known as a fire rainbow for its flame-like appearance, a
circumhorizon arc
is created by ice, not fire.
For a circumhorizon arc
to be visible, the Sun must be at least 58 degrees high in a sky where
cirrus clouds are present.
Furthermore, the numerous, flat,
hexagonal ice-crystals
that compose the
cirrus cloud must be
aligned horizontally
to properly
refract sunlight
like a single gigantic
prism.
Therefore, circumhorizon arcs are quite unusual to see.
Pictured
above,
however, a rare fire rainbow was captured above trees in
Whiting,
New Jersey,
USA in late
May.
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.