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Астронет: Астрономическая картинка дня Планета Земля в синий час http://www.variable-stars.ru/db/msg/1506560/eng |
Credit & Copyright: Matthias Ciprian
Explanation:
Nature photographers and other
fans of planet Earth
always look forward to
the blue hour.
That's the transition
in twilight,
just before sunrise or after sunset, when
the Sun is below the horizon but land and sky are still suffused with
beautiful bluish hues of light.
On August 8 this
early morning
blue hour panorama
scanned along the clear western sky, away from the impending sunrise.
A breathtaking scene, it looks down the slopes of Mt. Whitney,
from along the
John Muir Trail
toward rugged peaks of planet Earth's Sierra Nevada mountain range.
Above the horizon a faint pinkish band of back scattered sunlight,
the anti-twilight arch or
Belt of Venus,
borders the falling grey shadow of Earth itself.
Subtle bands of light across the clear sky are anti-crepuscular rays,
defined by
shadows
of clouds near the sunward horizon.
Actually following parallel lines
they seem to converge along the horizon at the point opposite
the rising Sun due to perspective.
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.