This is the sharpest image of Saturn's temperature emissions taken from
the ground; it is a mosaic of 35 individual exposures made at the W.M.
Keck I Observatory, Mauna Kea, Hawaii on Feb. 4, 2004.
The images to create this mosaic were taken with infrared radiation. The
mosaic was taken at a wavelength near 17.65 microns and is sensitive to
temperatures in Saturn's upper troposphere. The prominent hot spot at
the bottom of the image is right at Saturn's south pole. The warming of
the southern hemisphere was expected, as Saturn was just past southern
summer solstice, but the abrupt changes in temperature with latitude were
not expected. The tropospheric temperature increases toward the pole
abruptly near 70 degrees latitude from 88 to 89 Kelvin (-301 to -299
degrees Fahrenheit) and then to 91 Kelvin (-296 degrees Fahrenheit) right
at the pole.
Ring particles are not at a uniform temperature everywhere in their orbit
around Saturn. The ring particles are orbiting clockwise in this image.
Particles are coldest just after having cooled down in Saturn's shadow
(lower left). As they orbit Saturn, the particles increase in temperature
up to a maximum (lower right) just before passing behind Saturn again in
shadow.
A small section of the ring image is missing because of incomplete mosaic
coverage during the observing sequence.
