This image shows the location of Cassini's most precise measurements so
far of the surface temperatures at the active "tiger stripe" fractures
that cut the south polar region of Enceladus. The background image, which
shows the tiger stripe fracture named Damascus Sulcus, was obtained by
Cassini's cameras during the close Enceladus flyby on August 11, 2008 (see
PIA11113).
The yellow circles show the approximate location of two of the active
plumes of ice particles identified by the Cassini cameras. The red
rectangles show the region of Damascus Sulcus from which heat radiation
was measured by Cassini's Composite Infrared Spectrometer (CIRS) at about
the same time as the images were taken. The CIRS measurements indicate
temperatures up to at least 170 Kelvin (-103 Centigrade or -154
Fahrenheit) near Damascus Sulcus. This is more than 100 degrees Kelvin
(180 degrees Fahrenheit) warmer than the surrounding surface, due to heat
escaping from Enceladus' interior along the fractures. However, even
warmer temperatures are probable over smaller regions close to the tiger
stripes, and temperatures are expected to be warmer still below Enceladus'
surface. Therefore, subsurface temperatures may be high enough to melt ice
to create liquid water, as is suggested by recent Cassini measurements of
the salty composition of ice grains ejected from the tiger stripes.
The Cassini-Huygens mission is a cooperative project of NASA, the European
Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory,
a division of the California Institute of Technology in Pasadena, manages
the mission for NASA's Science Mission Directorate, Washington, D.C. The
Cassini orbiter was designed, developed and assembled at JPL. The
composite infrared spectrometer team is based at NASA's Goddard Space
Flight Center, Greenbelt, Md.
For more information about the Cassini-Huygens mission visit
http://saturn.jpl.nasa.gov/home/index.cfm. The composite infrared
spectrometer team homepage is http://cirs.gsfc.nasa.gov/.