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Астронет: Астрономическая картинка дня Солнечное и лунное гало http://variable-stars.ru/db/msg/1334803/eng |
Credit & Copyright: Göran Strand
Explanation:
Two pictures captured on April 1
are combined in this
creative
day
and
night
composite.
Separated in time by about 10 hours the images otherwise match, looking
along the coast at Östersund Sweden.
The relative times were chosen to show the Sun and a nearly full Moon
at the same place in the
cold, early springtime sky.
In the night scene Jupiter also shines above the waterfront lights,
while Sun and Moon are both surrounded by a beautiful circular ice halo.
The Sun and Moon halos really do align, each with an
angular radius of 22 degrees.
That radius is a constant, not determined by the brightness
of Sun or Moon but
only
by the hexagonal geometry of
atmospheric
ice crystals
and the reflection and refraction of light.
Of course tomorrow, April 4, will find the Sun and Moon
on opposite sides of planet Earth for a
total lunar eclipse.
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.