Астронет: Астрономическая картинка дня Равноденствие: от солнцестояния до солнцестояния http://variable-stars.ru/db/msg/1498261/eng |
Credit & Copyright: Tunç Tezel
(TWAN)
Explanation:
Today is an equinox, a date when day and night are equal.
Tomorrow, and every day until the next
equinox,
the night will be longer than the day in Earth's northern hemisphere,
and the day will be longer than the night in Earth's southern hemisphere.
An equinox
occurs midway between the two
solstices,
when the days and nights are the least equal.
The featured picture is a composite of hourly images taken of the Sun above
Bursa,
Turkey on key days from solstice
to
equinox to solstice.
The bottom Sun band was taken during the north's
winter solstice in 2007 December, when
the Sun
could not rise very high
in the sky nor stay above the horizon very long.
This lack of Sun caused
winter.
The top
Sun band was taken during the northern
summer solstice in 2008 June, when the
Sun rose highest in the sky and
stayed above the horizon for more than 12 hours.
This abundance of Sun caused
summer.
The middle band was taken during an
equinox in 2008 March, but it is the same sun band that
Earthlings see today, the day of the most recent
equinox.
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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.