Les couleurs de saturne par Cassini
What creates Saturn's colors?
The
featured picture of Saturn only slightly exaggerates what a
human
would see if hovering close to the giant ringed world.
The image was taken in 2005 by the robot
Cassini spacecraft that orbited
Saturn
from 2004 to 2017.
Here Saturn's majestic rings appear directly only as a curved line,
appearing brown, in part, from its
infrared glow.
The rings best show their complex structure in the
dark shadows
they create across the upper part of the planet.
The northern hemisphere of
Saturn can appear partly blue for the same reason that
Earth's skies can appear blue -- molecules in the cloudless portions
of both planet's atmospheres are better at scattering blue light than red.
When looking deep into
Saturn's clouds, however, the natural
gold hue of Saturn's clouds becomes dominant.
It is not known why southern Saturn does not show the same blue hue --
one hypothesis holds that clouds are higher there.
It is also
not known why some of Saturn's
clouds are colored gold.