Астронет: Астрономическая картинка дня Северная небесная башня http://variable-stars.ru/db/msg/1366003/eng |
Credit & Copyright: Anthony Ayiomamitis
(TWAN)
Explanation:
If you climbed to the top of this 13th century stone tower,
it looks like
you could reach out and touch the
North Celestial Pole,
the point at the center of all the star trail arcs.
The well-composed image
with scattered meteor streaks was recorded over a period of
five and half hours as a series of 45 second long exposures
spanning the dark of the night on July 7/8.
The exposures were made with a digital camera fixed to a tripod near
Marathon, Greece, planet Earth.
Of course, the graceful star trails reflect the
Earth's daily rotation around its axis.
By extension, the axis of rotation
leads to the center of the concentric arcs
in the night sky.
Convenient for northern hemisphere
night sky photographers and celestial navigators alike, the
bright star Polaris
is very close to the North Celestial
Pole and so makes the short bright trail in the tower's central gap.
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.