Астронет: Астрономическая картинка дня Равноденствие на Земле http://variable-stars.ru/db/msg/1321957/eng |
Credit & Copyright: Roscosmos / NTSOMZ /
zelenyikot.livejournal.com
Courtesy: Igor Tirsky, Vitaliy Egorov
Explanation:
Earth is at equinox.
Over the next 24 hours, day and night have nearly equal duration all over planet
Earth.
Technically,
equinox transpires at 2:29 am
Universal Time tomorrow,
but this occurs today in North and South America.
This September equinox signal that winter is approaching in the northern hemisphere,
and summer is approaching in the south.
At equinox, the dividing line between the sunlit half of Earth and the nighttime
half of Earth
temporarily passes through Earth's north and south spin poles.
This dividing line
is shown in clear detail in the
featured video,
taken by the Russian meteorological satellite
Elektro-L
during last year's September equinox.
The Elektro-L satellite is in
geostationary
orbit over one spot on
Earth's equator and always points directly toward the Earth.
The
featured video
shows a time lapse for an entire day surrounding the equinox,
with a new image taken every 30 minutes.
Cloud motions are visible as well as the
reflection of the Sun
are visible as the equinox day progressed.
The next Earth equinox is scheduled for March.
Courtesy: Igor Tirsky, Vitaliy Egorov
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Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
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rights apply.
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NASA /
GSFC
& Michigan Tech. U.