Астронет: Астрономическая картинка дня Аналемма над древней Немеей http://variable-stars.ru/db/msg/1198473/eng |
Credit & Copyright: Anthony Ayiomamitis
Explanation:
An anelemma
is that figure-8 curve that you get when
you mark
the position of the Sun at the same time
each day throughout planet
Earth's year.
Above, 44 separate
exposures (plus one foreground exposure)
were recorded on a single piece of film to illustrate
the regular solar motion -- a Herculean task performed
during the calendar year 2003.
Appropriately, in the foreground are the ruins at
Ancient Nemea where the hero of Greek Mythology pursued
the first of his twelve labours.
Solstices, like the one
that occurred at 0057 UT on June 21,
correspond to the top and bottom of the figure-8 or the
northern and southernmost excursions of the Sun in the sky.
The tilt of planet Earth's axis and the variation in speed as
it moves around its orbit combine to produce the graceful
analemma
curve.
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.