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Астронет: Астрономическая картинка дня Равноденствие на Сатурне http://www.astronet.ru/db/msg/1976606/eng |
Credit & Copyright: Imran Sultan
Explanation:
On Saturn, the rings tell you the season.
On Earth, today marks an equinox, the time when the
Earth's equator tilts directly toward the Sun.
Since
Saturn's grand rings
orbit along the planet's equator,
these rings appear most prominent --
from the direction of the Sun -- when the spin axis of
Saturn points toward the
Sun.
Conversely, when
Saturn's
spin axis points to the side, an equinox occurs,
and the edge-on rings are hard to see from not only the Sun -- but
Earth.
In the
featured montage, images of Saturn between the years of
2020 and 2025
have been superposed to show the giant planet passing,
with this year's equinox, from summer in the north to summer in the south.
Yesterday,
Saturn was coincidently about
as close as it gets to planet Earth,
and so this month the
ringed giant's orb is relatively bright and
visible
throughout the night.
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.