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Астронет: Астрономическая картинка дня Швейцарские Альпы, марсианское небо http://variable-stars.ru/db/msg/1726884/eng |
Credit & Copyright: Jens Bydal
Explanation:
Taken on February 6,
this snowy mountain and skyscape was captured
near Melchsee-Frutt, central Switzerland, planet Earth.
The reddish daylight and blue tinted glow around the afternoon Sun are
colors of
the Martian sky, though.
Of course both worlds have the same Sun.
From Mars, the Sun looks only about half as bright and 2/3 the size
compared to its appearance from Earth.
Lofted from the surface of Mars, fine dust particles suspended
in the thin Martian atmosphere are rich in the iron oxides that make
the Red Planet red.
They tend to absorb blue sunlight giving a red tinge to the
Martian sky,
while forward scattering still makes the light
appear relatively bluish near the smaller, fainter Martian Sun.
Normally Earth's denser atmosphere strongly scatters blue light, making
the terrestrial sky blue.
But on February 6 a
huge
cloud of dust
blown across the Mediterranean
from the Sahara desert reached the Swiss Alps, dimming the Sun and
lending that Alpine afternoon the colors of the Martian sky.
By the next day, only the snow was left covered with reddish dust.
News from Mars:
NASA
Perseverance Coverage
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.