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Астронет: Астрономическая картинка дня Полумесяц за греческим храмом http://variable-stars.ru/db/msg/1883579/eng |
Credit & Copyright: Elias Chasiotis
Explanation:
Why is a thin crescent moon never seen far from a horizon?
Because the only
geometry that gives a thin crescent lunar phase occurs when
the Moon
appears close to
the Sun
in the sky.
The crescent is not caused by the
shadow of the Earth,
but by seeing only a small part of the Moon directly illuminated by the Sun.
Moreover, the thickest part of the
crescent always occurs in the direction of the Sun.
In the evening, a
thin crescent Moon will set
shortly after the Sun and not be seen for the rest of the night.
Alternatively, in the morning, a
crescent Moon will rise shortly before the Sun after
not being seen for most of the night.
Pictured two weeks ago, a crescent moon was captured near the horizon, just
before sunrise, far behind remnants of the ancient
Temple of
Poseidon
in
Greece.
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.