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Астронет: Астрономическая картинка дня Северный зелёный луч http://variable-stars.ru/db/msg/1266295/eng |
Credit & Copyright: Göran Strand
Explanation:
As seen from
Frösön
island in northern Sweden the Sun did set a day after the
summer solstice.
From that location below the
arctic circle
it settled slowly behind the northern horizon.
During the sunset's final minute,
this remarkable sequence
of 7 images follows the distorted edge
of the solar disk as it just disappears against a distant tree line,
capturing both a
green
and blue flash.
Not a myth even in a land
of runes,
the colorful but ellusive glints are caused by
atmospheric refraction enhanced by long, low, sight lines and
strong atmospheric temperature gradients.
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.